Changes with nginx 1.1.4 20 Sep 2011v1.1.4

*) Feature: the ngx_http_upstream_keepalive module.

*) Feature: the "proxy_http_version" directive.

*) Feature: the "fastcgi_keep_conn" directive.

*) Feature: the "worker_aio_requests" directive.

*) Bugfix: if nginx was built --with-file-aio it could not be run on
Linux kernel which did not support AIO.

*) Bugfix: in Linux AIO error processing.
Thanks to Hagai Avrahami.

*) Bugfix: reduced memory consumption for long-lived requests.

*) Bugfix: the module ngx_http_mp4_module did not support 64-bit MP4
"co64" atom.

41 files changed, 2064 insertions, 231 deletions

diff --git a/CHANGES b/CHANGES
index bce98b7ea..16856a62f 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,4 +1,26 @@
 
+Changes with nginx 1.1.4                                         20 Sep 2011
+
+    *) Feature: the ngx_http_upstream_keepalive module.
+
+    *) Feature: the "proxy_http_version" directive.
+
+    *) Feature: the "fastcgi_keep_conn" directive.
+
+    *) Feature: the "worker_aio_requests" directive.
+
+    *) Bugfix: if nginx was built --with-file-aio it could not be run on
+       Linux kernel which did not support AIO.
+
+    *) Bugfix: in Linux AIO error processing.
+       Thanks to Hagai Avrahami.
+
+    *) Bugfix: reduced memory consumption for long-lived requests.
+
+    *) Bugfix: the module ngx_http_mp4_module did not support 64-bit MP4
+       "co64" atom.
+
+
 Changes with nginx 1.1.3                                         14 Sep 2011
 
     *) Feature: the module ngx_http_mp4_module.
diff --git a/CHANGES.ru b/CHANGES.ru
index 24fd20b01..02fd37a59 100644
--- a/CHANGES.ru
+++ b/CHANGES.ru
@@ -1,4 +1,26 @@
 
+Изменения в nginx 1.1.4                                           20.09.2011
+
+    *) Добавление: модуль ngx_http_upstream_keepalive.
+
+    *) Добавление: директива proxy_http_version.
+
+    *) Добавление: директива fastcgi_keep_conn.
+
+    *) Добавление: директива worker_aio_requests.
+
+    *) Исправление: если nginx был собран с файловым AIO, он не мог
+       запускаться на Linux без поддержки AIO.
+
+    *) Исправление: в обработке ошибок при работе с Linux AIO.
+       Спасибо Hagai Avrahami.
+
+    *) Исправление: уменьшено потребление памяти для долгоживущих запросов.
+
+    *) Исправление: модуль ngx_http_mp4_module не поддерживал 64-битный
+       MP4-атом co64.
+
+
 Изменения в nginx 1.1.3                                           14.09.2011
 
     *) Добавление: модуль ngx_http_mp4_module.
diff --git a/auto/modules b/auto/modules
index b13bcb25b..57f0f89e7 100644
--- a/auto/modules
+++ b/auto/modules
@@ -344,6 +344,11 @@ if [ $HTTP_UPSTREAM_IP_HASH = YES ]; then
     HTTP_SRCS="$HTTP_SRCS $HTTP_UPSTREAM_IP_HASH_SRCS"
 fi
 
+if [ $HTTP_UPSTREAM_KEEPALIVE = YES ]; then
+    HTTP_MODULES="$HTTP_MODULES $HTTP_UPSTREAM_KEEPALIVE_MODULE"
+    HTTP_SRCS="$HTTP_SRCS $HTTP_UPSTREAM_KEEPALIVE_SRCS"
+fi
+
 if [ $HTTP_STUB_STATUS = YES ]; then
     have=NGX_STAT_STUB . auto/have
     HTTP_MODULES="$HTTP_MODULES ngx_http_stub_status_module"
diff --git a/auto/options b/auto/options
index f30917c89..2019498c3 100644
--- a/auto/options
+++ b/auto/options
@@ -95,6 +95,7 @@ HTTP_FLV=NO
 HTTP_MP4=NO
 HTTP_GZIP_STATIC=NO
 HTTP_UPSTREAM_IP_HASH=YES
+HTTP_UPSTREAM_KEEPALIVE=YES
 
 # STUB
 HTTP_STUB_STATUS=NO
@@ -231,6 +232,7 @@ do
         --without-http_empty_gif_module) HTTP_EMPTY_GIF=NO          ;;
         --without-http_browser_module)   HTTP_BROWSER=NO            ;;
         --without-http_upstream_ip_hash_module) HTTP_UPSTREAM_IP_HASH=NO ;;
+        --without-http_upstream_keepalive_module) HTTP_UPSTREAM_KEEPALIVE=NO ;;
 
         --with-http_perl_module)         HTTP_PERL=YES              ;;
         --with-perl_modules_path=*)      NGX_PERL_MODULES="$value"  ;;
diff --git a/auto/sources b/auto/sources
index 00ec7b3d4..6c973f66b 100644
--- a/auto/sources
+++ b/auto/sources
@@ -475,6 +475,11 @@ HTTP_UPSTREAM_IP_HASH_MODULE=ngx_http_upstream_ip_hash_module
 HTTP_UPSTREAM_IP_HASH_SRCS=src/http/modules/ngx_http_upstream_ip_hash_module.c
 
 
+HTTP_UPSTREAM_KEEPALIVE_MODULE=ngx_http_upstream_keepalive_module
+HTTP_UPSTREAM_KEEPALIVE_SRCS=" \
+    src/http/modules/ngx_http_upstream_keepalive_module.c"
+
+
 MAIL_INCS="src/mail"
 
 MAIL_DEPS="src/mail/ngx_mail.h"
diff --git a/html/ngx_core_module.html b/html/ngx_core_module.html
index 705cd7bed..4c5e8d8ac 100644
--- a/html/ngx_core_module.html
+++ b/html/ngx_core_module.html
@@ -1,4 +1,4 @@
-<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><title>Core Module</title></head><body><a name="example"></a><center><h4>Example Configuration</h4></center><p><blockquote><pre>
+<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><title>Core Module</title></head><body><center><h3>Core Module</h3></center><a name="example"></a><center><h4>Example Configuration</h4></center><p><blockquote><pre>
 user www www;
 worker_processes 2;
 
@@ -27,9 +27,8 @@ variable inheritance during a
 <a href="control.html#upgrade">live upgrade</a>
 of an executable file;
 </li><li>
-use of variables by the
-<a href="http/ngx_http_perl_module.html">http_perl</a>
-module;
+use of variables by the module
+<a href="http/ngx_http_perl_module.html">ngx_http_perl_module</a>;
 </li><li>
 use of variables by worker processes.
 Please bear in mind that controlling system libraries in this way
@@ -40,9 +39,9 @@ An exception from this is an above mentioned
 <a href="control.html#upgrade">live upgrade</a>
 of an executable file.
 </li></ul></p><p>
-The TZ variable is always inherited and made available to the
-<a href="http/ngx_http_perl_module.html">http_perl</a>
-module, unless configured explicitly.
+The TZ variable is always inherited and made available to the module
+<a href="http/ngx_http_perl_module.html">ngx_http_perl_module</a>,
+unless configured explicitly.
 </p><p>
 Usage example:
 <blockquote><pre>
diff --git a/src/core/nginx.h b/src/core/nginx.h
index a47054bcb..ca6cca092 100644
--- a/src/core/nginx.h
+++ b/src/core/nginx.h
@@ -8,8 +8,8 @@
 #define _NGINX_H_INCLUDED_
 
 
-#define nginx_version      1001003
-#define NGINX_VERSION      "1.1.3"
+#define nginx_version      1001004
+#define NGINX_VERSION      "1.1.4"
 #define NGINX_VER          "nginx/" NGINX_VERSION
 
 #define NGINX_VAR          "NGINX"
diff --git a/src/core/ngx_buf.c b/src/core/ngx_buf.c
index 2f2c43721..53cd50cea 100644
--- a/src/core/ngx_buf.c
+++ b/src/core/ngx_buf.c
@@ -180,7 +180,7 @@ ngx_chain_get_free_buf(ngx_pool_t *p, ngx_chain_t **free)
 
 
 void
-ngx_chain_update_chains(ngx_chain_t **free, ngx_chain_t **busy,
+ngx_chain_update_chains(ngx_pool_t *p, ngx_chain_t **free, ngx_chain_t **busy,
     ngx_chain_t **out, ngx_buf_tag_t tag)
 {
     ngx_chain_t  *cl;
@@ -197,19 +197,21 @@ ngx_chain_update_chains(ngx_chain_t **free, ngx_chain_t **busy,
     *out = NULL;
 
     while (*busy) {
-        if (ngx_buf_size((*busy)->buf) != 0) {
+        cl = *busy;
+
+        if (ngx_buf_size(cl->buf) != 0) {
             break;
         }
 
-        if ((*busy)->buf->tag != tag) {
-            *busy = (*busy)->next;
+        if (cl->buf->tag != tag) {
+            *busy = cl->next;
+            ngx_free_chain(p, cl);
             continue;
         }
 
-        (*busy)->buf->pos = (*busy)->buf->start;
-        (*busy)->buf->last = (*busy)->buf->start;
+        cl->buf->pos = cl->buf->start;
+        cl->buf->last = cl->buf->start;
 
-        cl = *busy;
         *busy = cl->next;
         cl->next = *free;
         *free = cl;
diff --git a/src/core/ngx_buf.h b/src/core/ngx_buf.h
index 847eaad05..a6bf39ff3 100644
--- a/src/core/ngx_buf.h
+++ b/src/core/ngx_buf.h
@@ -154,8 +154,8 @@ ngx_int_t ngx_chain_writer(void *ctx, ngx_chain_t *in);
 ngx_int_t ngx_chain_add_copy(ngx_pool_t *pool, ngx_chain_t **chain,
     ngx_chain_t *in);
 ngx_chain_t *ngx_chain_get_free_buf(ngx_pool_t *p, ngx_chain_t **free);
-void ngx_chain_update_chains(ngx_chain_t **free, ngx_chain_t **busy,
-    ngx_chain_t **out, ngx_buf_tag_t tag);
+void ngx_chain_update_chains(ngx_pool_t *p, ngx_chain_t **free,
+    ngx_chain_t **busy, ngx_chain_t **out, ngx_buf_tag_t tag);
 
 
 #endif /* _NGX_BUF_H_INCLUDED_ */
diff --git a/src/core/ngx_cycle.c b/src/core/ngx_cycle.c
index 968056c42..db473571f 100644
--- a/src/core/ngx_cycle.c
+++ b/src/core/ngx_cycle.c
@@ -739,7 +739,7 @@ old_shm_zone_done:
         ngx_temp_pool = ngx_create_pool(128, cycle->log);
         if (ngx_temp_pool == NULL) {
             ngx_log_error(NGX_LOG_EMERG, cycle->log, 0,
-                          "can not create ngx_temp_pool");
+                          "could not create ngx_temp_pool");
             exit(1);
         }
 
diff --git a/src/core/ngx_output_chain.c b/src/core/ngx_output_chain.c
index 4f100a818..e45f0342d 100644
--- a/src/core/ngx_output_chain.c
+++ b/src/core/ngx_output_chain.c
@@ -208,7 +208,8 @@ ngx_output_chain(ngx_output_chain_ctx_t *ctx, ngx_chain_t *in)
             return last;
         }
 
-        ngx_chain_update_chains(&ctx->free, &ctx->busy, &out, ctx->tag);
+        ngx_chain_update_chains(ctx->pool, &ctx->free, &ctx->busy, &out,
+                                ctx->tag);
         last_out = &out;
     }
 }
diff --git a/src/core/ngx_palloc.c b/src/core/ngx_palloc.c
index 35f13119c..9eac114b7 100644
--- a/src/core/ngx_palloc.c
+++ b/src/core/ngx_palloc.c
@@ -68,7 +68,7 @@ ngx_destroy_pool(ngx_pool_t *pool)
 
     /*
      * we could allocate the pool->log from this pool
-     * so we can not use this log while the free()ing the pool
+     * so we cannot use this log while free()ing the pool
      */
 
     for (p = pool, n = pool->d.next; /* void */; p = n, n = n->d.next) {
diff --git a/src/core/ngx_string.c b/src/core/ngx_string.c
index 4dcfe01eb..75bc6578d 100644
--- a/src/core/ngx_string.c
+++ b/src/core/ngx_string.c
@@ -381,7 +381,7 @@ ngx_vslprintf(u_char *buf, u_char *last, const char *fmt, va_list args)
 
                     /*
                      * (int64_t) cast is required for msvc6:
-                     * it can not convert uint64_t to double
+                     * it cannot convert uint64_t to double
                      */
                     ui64 = (uint64_t) ((f - (int64_t) ui64) * scale + 0.5);
 
diff --git a/src/event/modules/ngx_epoll_module.c b/src/event/modules/ngx_epoll_module.c
index e30501b00..31c10c6dc 100644
--- a/src/event/modules/ngx_epoll_module.c
+++ b/src/event/modules/ngx_epoll_module.c
@@ -86,6 +86,7 @@ int eventfd(u_int initval)
 
 typedef struct {
     ngx_uint_t  events;
+    ngx_uint_t  aio_requests;
 } ngx_epoll_conf_t;
 
 
@@ -133,6 +134,13 @@ static ngx_command_t  ngx_epoll_commands[] = {
       offsetof(ngx_epoll_conf_t, events),
       NULL },
 
+    { ngx_string("worker_aio_requests"),
+      NGX_EVENT_CONF|NGX_CONF_TAKE1,
+      ngx_conf_set_num_slot,
+      0,
+      offsetof(ngx_epoll_conf_t, aio_requests),
+      NULL },
+
       ngx_null_command
 };
 
@@ -184,7 +192,7 @@ ngx_module_t  ngx_epoll_module = {
  * into single eventfd() function with different number of parameters.
  */
 
-static long
+static int
 io_setup(u_int nr_reqs, aio_context_t *ctx)
 {
     return syscall(SYS_io_setup, nr_reqs, ctx);
@@ -198,13 +206,81 @@ io_destroy(aio_context_t ctx)
 }
 
 
-static long
+static int
 io_getevents(aio_context_t ctx, long min_nr, long nr, struct io_event *events,
     struct timespec *tmo)
 {
     return syscall(SYS_io_getevents, ctx, min_nr, nr, events, tmo);
 }
 
+
+static void
+ngx_epoll_aio_init(ngx_cycle_t *cycle, ngx_epoll_conf_t *epcf)
+{
+    int                 n;
+    struct epoll_event  ee;
+
+    ngx_eventfd = syscall(SYS_eventfd, 0);
+
+    if (ngx_eventfd == -1) {
+        ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
+                      "eventfd() failed");
+        ngx_file_aio = 0;
+        return;
+    }
+
+    ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
+                   "eventfd: %d", ngx_eventfd);
+
+    n = 1;
+
+    if (ioctl(ngx_eventfd, FIONBIO, &n) == -1) {
+        ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
+                      "ioctl(eventfd, FIONBIO) failed");
+        goto failed;
+    }
+
+    if (io_setup(epcf->aio_requests, &ngx_aio_ctx) == -1) {
+        ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
+                      "io_setup() failed");
+        goto failed;
+    }
+
+    ngx_eventfd_event.data = &ngx_eventfd_conn;
+    ngx_eventfd_event.handler = ngx_epoll_eventfd_handler;
+    ngx_eventfd_event.log = cycle->log;
+    ngx_eventfd_event.active = 1;
+    ngx_eventfd_conn.fd = ngx_eventfd;
+    ngx_eventfd_conn.read = &ngx_eventfd_event;
+    ngx_eventfd_conn.log = cycle->log;
+
+    ee.events = EPOLLIN|EPOLLET;
+    ee.data.ptr = &ngx_eventfd_conn;
+
+    if (epoll_ctl(ep, EPOLL_CTL_ADD, ngx_eventfd, &ee) != -1) {
+        return;
+    }
+
+    ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
+                  "epoll_ctl(EPOLL_CTL_ADD, eventfd) failed");
+
+    if (io_destroy(ngx_aio_ctx) == -1) {
+        ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
+                      "io_destroy() failed");
+    }
+
+failed:
+
+    if (close(ngx_eventfd) == -1) {
+        ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
+                      "eventfd close() failed");
+    }
+
+    ngx_eventfd = -1;
+    ngx_aio_ctx = 0;
+    ngx_file_aio = 0;
+}
+
 #endif
 
 
@@ -225,52 +301,9 @@ ngx_epoll_init(ngx_cycle_t *cycle, ngx_msec_t timer)
         }
 
 #if (NGX_HAVE_FILE_AIO)
-        {
-        int                 n;
-        struct epoll_event  ee;
-
-        ngx_eventfd = syscall(SYS_eventfd, 0);
-
-        if (ngx_eventfd == -1) {
-            ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
-                          "eventfd() failed");
-            return NGX_ERROR;
-        }
-
-        n = 1;
-
-        if (ioctl(ngx_eventfd, FIONBIO, &n) == -1) {
-            ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
-                          "ioctl(eventfd, FIONBIO) failed");
-        }
-
-        ngx_log_debug1(NGX_LOG_DEBUG_EVENT, cycle->log, 0,
-                       "eventfd: %d", ngx_eventfd);
 
-        n = io_setup(1024, &ngx_aio_ctx);
+        ngx_epoll_aio_init(cycle, epcf);
 
-        if (n != 0) {
-            ngx_log_error(NGX_LOG_EMERG, cycle->log, -n, "io_setup() failed");
-            return NGX_ERROR;
-        }
-
-        ngx_eventfd_event.data = &ngx_eventfd_conn;
-        ngx_eventfd_event.handler = ngx_epoll_eventfd_handler;
-        ngx_eventfd_event.log = cycle->log;
-        ngx_eventfd_event.active = 1;
-        ngx_eventfd_conn.fd = ngx_eventfd;
-        ngx_eventfd_conn.read = &ngx_eventfd_event;
-        ngx_eventfd_conn.log = cycle->log;
-
-        ee.events = EPOLLIN|EPOLLET;
-        ee.data.ptr = &ngx_eventfd_conn;
-
-        if (epoll_ctl(ep, EPOLL_CTL_ADD, ngx_eventfd, &ee) == -1) {
-            ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno,
-                          "epoll_ctl(EPOLL_CTL_ADD, eventfd) failed");
-            return NGX_ERROR;
-        }
-        }
 #endif
     }
 
@@ -316,9 +349,19 @@ ngx_epoll_done(ngx_cycle_t *cycle)
 
 #if (NGX_HAVE_FILE_AIO)
 
-    if (io_destroy(ngx_aio_ctx) != 0) {
-        ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
-                      "io_destroy() failed");
+    if (ngx_eventfd != -1) {
+
+        if (io_destroy(ngx_aio_ctx) == -1) {
+            ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
+                          "io_destroy() failed");
+        }
+
+        if (close(ngx_eventfd) == -1) {
+            ngx_log_error(NGX_LOG_ALERT, cycle->log, ngx_errno,
+                          "eventfd close() failed");
+        }
+
+        ngx_eventfd = -1;
     }
 
     ngx_aio_ctx = 0;
@@ -667,8 +710,8 @@ ngx_epoll_process_events(ngx_cycle_t *cycle, ngx_msec_t timer, ngx_uint_t flags)
 static void
 ngx_epoll_eventfd_handler(ngx_event_t *ev)
 {
-    int               n;
-    long              i, events;
+    int               n, events;
+    long              i;
     uint64_t          ready;
     ngx_err_t         err;
     ngx_event_t      *e;
@@ -738,8 +781,9 @@ ngx_epoll_eventfd_handler(ngx_event_t *ev)
             return;
         }
 
-        /* events < 0 */
-        ngx_log_error(NGX_LOG_ALERT, ev->log, -events, "io_getevents() failed");
+        /* events == -1 */
+        ngx_log_error(NGX_LOG_ALERT, ev->log, ngx_errno,
+                      "io_getevents() failed");
         return;
     }
 }
@@ -758,6 +802,7 @@ ngx_epoll_create_conf(ngx_cycle_t *cycle)
     }
 
     epcf->events = NGX_CONF_UNSET;
+    epcf->aio_requests = NGX_CONF_UNSET;
 
     return epcf;
 }
@@ -769,6 +814,7 @@ ngx_epoll_init_conf(ngx_cycle_t *cycle, void *conf)
     ngx_epoll_conf_t *epcf = conf;
 
     ngx_conf_init_uint_value(epcf->events, 512);
+    ngx_conf_init_uint_value(epcf->aio_requests, 32);
 
     return NGX_CONF_OK;
 }
diff --git a/src/event/ngx_event.c b/src/event/ngx_event.c
index c57d37ec4..8a472ffe8 100644
--- a/src/event/ngx_event.c
+++ b/src/event/ngx_event.c
@@ -1027,7 +1027,7 @@ ngx_event_use(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
                                "when the server runs without a master process "
                                "the \"%V\" event type must be the same as "
                                "in previous configuration - \"%s\" "
-                               "and it can not be changed on the fly, "
+                               "and it cannot be changed on the fly, "
                                "to change it you need to stop server "
                                "and start it again",
                                &value[1], old_ecf->name);
diff --git a/src/event/ngx_event_pipe.c b/src/event/ngx_event_pipe.c
index 53d738f0a..4f45bb872 100644
--- a/src/event/ngx_event_pipe.c
+++ b/src/event/ngx_event_pipe.c
@@ -392,8 +392,32 @@ ngx_event_pipe_read_upstream(ngx_event_pipe_t *p)
                        cl->buf->file_last - cl->buf->file_pos);
     }
 
+    ngx_log_debug1(NGX_LOG_DEBUG_EVENT, p->log, 0,
+                   "pipe length: %O", p->length);
+
 #endif
 
+    if (p->free_raw_bufs && p->length != -1) {
+        cl = p->free_raw_bufs;
+
+        if (cl->buf->last - cl->buf->pos >= p->length) {
+
+            /* STUB */ cl->buf->num = p->num++;
+
+            if (p->input_filter(p, cl->buf) == NGX_ERROR) {
+                 return NGX_ABORT;
+            }
+
+            p->free_raw_bufs = cl->next;
+            ngx_free_chain(p->pool, cl);
+        }
+    }
+
+    if (p->length == 0) {
+        p->upstream_done = 1;
+        p->read = 1;
+    }
+
     if ((p->upstream_eof || p->upstream_error) && p->free_raw_bufs) {
 
         /* STUB */ p->free_raw_bufs->buf->num = p->num++;
@@ -633,13 +657,13 @@ ngx_event_pipe_write_to_downstream(ngx_event_pipe_t *p)
 
         rc = p->output_filter(p->output_ctx, out);
 
+        ngx_chain_update_chains(p->pool, &p->free, &p->busy, &out, p->tag);
+
         if (rc == NGX_ERROR) {
             p->downstream_error = 1;
             return ngx_event_pipe_drain_chains(p);
         }
 
-        ngx_chain_update_chains(&p->free, &p->busy, &out, p->tag);
-
         for (cl = p->free; cl; cl = cl->next) {
 
             if (cl->buf->temp_file) {
@@ -848,6 +872,12 @@ ngx_event_pipe_copy_input_filter(ngx_event_pipe_t *p, ngx_buf_t *buf)
     }
     p->last_in = &cl->next;
 
+    if (p->length == -1) {
+        return NGX_OK;
+    }
+
+    p->length -= b->last - b->pos;
+
     return NGX_OK;
 }
 
diff --git a/src/event/ngx_event_pipe.h b/src/event/ngx_event_pipe.h
index 00b8acf66..26334673c 100644
--- a/src/event/ngx_event_pipe.h
+++ b/src/event/ngx_event_pipe.h
@@ -65,6 +65,7 @@ struct ngx_event_pipe_s {
     ssize_t            busy_size;
 
     off_t              read_length;
+    off_t              length;
 
     off_t              max_temp_file_size;
     ssize_t            temp_file_write_size;
diff --git a/src/event/ngx_event_timer.c b/src/event/ngx_event_timer.c
index 2931a9f4e..76a1a1f41 100644
--- a/src/event/ngx_event_timer.c
+++ b/src/event/ngx_event_timer.c
@@ -103,11 +103,11 @@ ngx_event_expire_timers(void)
             if (ngx_threaded && ngx_trylock(ev->lock) == 0) {
 
                 /*
-                 * We can not change the timer of the event that is been
-                 * handling by another thread.  And we can not easy walk
-                 * the rbtree to find a next expired timer so we exit the loop.
-                 * However it should be rare case when the event that is
-                 * been handling has expired timer.
+                 * We cannot change the timer of the event that is being
+                 * handled by another thread.  And we cannot easy walk
+                 * the rbtree to find next expired timer so we exit the loop.
+                 * However, it should be a rare case when the event that is
+                 * being handled has an expired timer.
                  */
 
                 ngx_log_debug1(NGX_LOG_DEBUG_EVENT, ev->log, 0,
diff --git a/src/http/modules/ngx_http_chunked_filter_module.c b/src/http/modules/ngx_http_chunked_filter_module.c
index 9c4c5de14..e6ae1c99d 100644
--- a/src/http/modules/ngx_http_chunked_filter_module.c
+++ b/src/http/modules/ngx_http_chunked_filter_module.c
@@ -9,6 +9,12 @@
 #include <ngx_http.h>
 
 
+typedef struct {
+    ngx_chain_t         *free;
+    ngx_chain_t         *busy;
+} ngx_http_chunked_filter_ctx_t;
+
+
 static ngx_int_t ngx_http_chunked_filter_init(ngx_conf_t *cf);
 
 
@@ -50,7 +56,8 @@ static ngx_http_output_body_filter_pt    ngx_http_next_body_filter;
 static ngx_int_t
 ngx_http_chunked_header_filter(ngx_http_request_t *r)
 {
-    ngx_http_core_loc_conf_t  *clcf;
+    ngx_http_core_loc_conf_t       *clcf;
+    ngx_http_chunked_filter_ctx_t  *ctx;
 
     if (r->headers_out.status == NGX_HTTP_NOT_MODIFIED
         || r->headers_out.status == NGX_HTTP_NO_CONTENT
@@ -70,6 +77,14 @@ ngx_http_chunked_header_filter(ngx_http_request_t *r)
             if (clcf->chunked_transfer_encoding) {
                 r->chunked = 1;
 
+                ctx = ngx_pcalloc(r->pool,
+                                  sizeof(ngx_http_chunked_filter_ctx_t));
+                if (ctx == NULL) {
+                    return NGX_ERROR;
+                }
+
+                ngx_http_set_ctx(r, ctx, ngx_http_chunked_filter_module);
+
             } else {
                 r->keepalive = 0;
             }
@@ -83,17 +98,21 @@ ngx_http_chunked_header_filter(ngx_http_request_t *r)
 static ngx_int_t
 ngx_http_chunked_body_filter(ngx_http_request_t *r, ngx_chain_t *in)
 {
-    u_char       *chunk;
-    off_t         size;
-    ngx_buf_t    *b;
-    ngx_chain_t   out, tail, *cl, *tl, **ll;
+    u_char                         *chunk;
+    off_t                           size;
+    ngx_int_t                       rc;
+    ngx_buf_t                      *b;
+    ngx_chain_t                    *out, *cl, *tl, **ll;
+    ngx_http_chunked_filter_ctx_t  *ctx;
 
     if (in == NULL || !r->chunked || r->header_only) {
         return ngx_http_next_body_filter(r, in);
     }
 
-    out.buf = NULL;
-    ll = &out.next;
+    ctx = ngx_http_get_module_ctx(r, ngx_http_chunked_filter_module);
+
+    out = NULL;
+    ll = &out;
 
     size = 0;
     cl = in;
@@ -127,31 +146,46 @@ ngx_http_chunked_body_filter(ngx_http_request_t *r, ngx_chain_t *in)
     }
 
     if (size) {
-        b = ngx_calloc_buf(r->pool);
-        if (b == NULL) {
+        tl = ngx_chain_get_free_buf(r->pool, &ctx->free);
+        if (tl == NULL) {
             return NGX_ERROR;
         }
 
-        /* the "0000000000000000" is 64-bit hexadimal string */
+        b = tl->buf;
+        chunk = b->start;
 
-        chunk = ngx_palloc(r->pool, sizeof("0000000000000000" CRLF) - 1);
         if (chunk == NULL) {
-            return NGX_ERROR;
+            /* the "0000000000000000" is 64-bit hexadecimal string */
+
+            chunk = ngx_palloc(r->pool, sizeof("0000000000000000" CRLF) - 1);
+            if (chunk == NULL) {
+                return NGX_ERROR;
+            }
+
+            b->start = chunk;
+            b->end = chunk + sizeof("0000000000000000" CRLF) - 1;
         }
 
+        b->tag = (ngx_buf_tag_t) &ngx_http_chunked_filter_module;
+        b->memory = 0;
         b->temporary = 1;
         b->pos = chunk;
         b->last = ngx_sprintf(chunk, "%xO" CRLF, size);
 
-        out.buf = b;
+        tl->next = out;
+        out = tl;
     }
 
     if (cl->buf->last_buf) {
-        b = ngx_calloc_buf(r->pool);
-        if (b == NULL) {
+        tl = ngx_chain_get_free_buf(r->pool, &ctx->free);
+        if (tl == NULL) {
             return NGX_ERROR;
         }
 
+        b = tl->buf;
+
+        b->tag = (ngx_buf_tag_t) &ngx_http_chunked_filter_module;
+        b->temporary = 0;
         b->memory = 1;
         b->last_buf = 1;
         b->pos = (u_char *) CRLF "0" CRLF CRLF;
@@ -159,35 +193,38 @@ ngx_http_chunked_body_filter(ngx_http_request_t *r, ngx_chain_t *in)
 
         cl->buf->last_buf = 0;
 
-        if (size == 0) {
-            b->pos += 2;
-            out.buf = b;
-            out.next = NULL;
-
-            return ngx_http_next_body_filter(r, &out);
-        }
+        *ll = tl;
 
-    } else {
         if (size == 0) {
-            *ll = NULL;
-            return ngx_http_next_body_filter(r, out.next);
+            b->pos += 2;
         }
 
-        b = ngx_calloc_buf(r->pool);
-        if (b == NULL) {
+    } else if (size > 0) {
+        tl = ngx_chain_get_free_buf(r->pool, &ctx->free);
+        if (tl == NULL) {
             return NGX_ERROR;
         }
 
+        b = tl->buf;
+
+        b->tag = (ngx_buf_tag_t) &ngx_http_chunked_filter_module;
+        b->temporary = 0;
         b->memory = 1;
         b->pos = (u_char *) CRLF;
         b->last = b->pos + 2;
+
+        *ll = tl;
+
+    } else {
+        *ll = NULL;
     }
 
-    tail.buf = b;
-    tail.next = NULL;
-    *ll = &tail;
+    rc = ngx_http_next_body_filter(r, out);
+
+    ngx_chain_update_chains(r->pool, &ctx->free, &ctx->busy, &out,
+                            (ngx_buf_tag_t) &ngx_http_chunked_filter_module);
 
-    return ngx_http_next_body_filter(r, &out);
+    return rc;
 }
 
 
diff --git a/src/http/modules/ngx_http_dav_module.c b/src/http/modules/ngx_http_dav_module.c
index 0761c1654..3bd9d3e94 100644
--- a/src/http/modules/ngx_http_dav_module.c
+++ b/src/http/modules/ngx_http_dav_module.c
@@ -158,7 +158,7 @@ ngx_http_dav_handler(ngx_http_request_t *r)
 
         if (r->uri.data[r->uri.len - 1] == '/') {
             ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
-                          "can not PUT to a collection");
+                          "cannot PUT to a collection");
             return NGX_HTTP_CONFLICT;
         }
 
diff --git a/src/http/modules/ngx_http_fastcgi_module.c b/src/http/modules/ngx_http_fastcgi_module.c
index 0bc95f8da..6f639acc2 100644
--- a/src/http/modules/ngx_http_fastcgi_module.c
+++ b/src/http/modules/ngx_http_fastcgi_module.c
@@ -26,6 +26,8 @@ typedef struct {
     ngx_hash_t                     headers_hash;
     ngx_uint_t                     header_params;
 
+    ngx_flag_t                     keep_conn;
+
 #if (NGX_HTTP_CACHE)
     ngx_http_complex_value_t       cache_key;
 #endif
@@ -77,6 +79,8 @@ typedef struct {
 
 #define NGX_HTTP_FASTCGI_RESPONDER      1
 
+#define NGX_HTTP_FASTCGI_KEEP_CONN      1
+
 #define NGX_HTTP_FASTCGI_BEGIN_REQUEST  1
 #define NGX_HTTP_FASTCGI_ABORT_REQUEST  2
 #define NGX_HTTP_FASTCGI_END_REQUEST    3
@@ -130,6 +134,7 @@ static ngx_int_t ngx_http_fastcgi_create_key(ngx_http_request_t *r);
 static ngx_int_t ngx_http_fastcgi_create_request(ngx_http_request_t *r);
 static ngx_int_t ngx_http_fastcgi_reinit_request(ngx_http_request_t *r);
 static ngx_int_t ngx_http_fastcgi_process_header(ngx_http_request_t *r);
+static ngx_int_t ngx_http_fastcgi_input_filter_init(void *data);
 static ngx_int_t ngx_http_fastcgi_input_filter(ngx_event_pipe_t *p,
     ngx_buf_t *buf);
 static ngx_int_t ngx_http_fastcgi_process_record(ngx_http_request_t *r,
@@ -437,6 +442,13 @@ static ngx_command_t  ngx_http_fastcgi_commands[] = {
       offsetof(ngx_http_fastcgi_loc_conf_t, catch_stderr),
       NULL },
 
+    { ngx_string("fastcgi_keep_conn"),
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_FLAG,
+      ngx_conf_set_flag_slot,
+      NGX_HTTP_LOC_CONF_OFFSET,
+      offsetof(ngx_http_fastcgi_loc_conf_t, keep_conn),
+      NULL },
+
       ngx_null_command
 };
 
@@ -600,6 +612,8 @@ ngx_http_fastcgi_handler(ngx_http_request_t *r)
     u->pipe->input_filter = ngx_http_fastcgi_input_filter;
     u->pipe->input_ctx = r;
 
+    u->input_filter_init = ngx_http_fastcgi_input_filter_init;
+
     rc = ngx_http_read_client_request_body(r, ngx_http_upstream_init);
 
     if (rc >= NGX_HTTP_SPECIAL_RESPONSE) {
@@ -841,6 +855,9 @@ ngx_http_fastcgi_create_request(ngx_http_request_t *r)
 
     cl->buf = b;
 
+    ngx_http_fastcgi_request_start.br.flags =
+        flcf->keep_conn ? NGX_HTTP_FASTCGI_KEEP_CONN : 0;
+
     ngx_memcpy(b->pos, &ngx_http_fastcgi_request_start,
                sizeof(ngx_http_fastcgi_request_start_t));
 
@@ -1574,14 +1591,30 @@ ngx_http_fastcgi_process_header(ngx_http_request_t *r)
 
 
 static ngx_int_t
+ngx_http_fastcgi_input_filter_init(void *data)
+{
+    ngx_http_request_t           *r = data;
+    ngx_http_fastcgi_loc_conf_t  *flcf;
+
+    flcf = ngx_http_get_module_loc_conf(r, ngx_http_fastcgi_module);
+
+    r->upstream->pipe->length = flcf->keep_conn ?
+                                (off_t) sizeof(ngx_http_fastcgi_header_t) : -1;
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t
 ngx_http_fastcgi_input_filter(ngx_event_pipe_t *p, ngx_buf_t *buf)
 {
-    u_char                  *m, *msg;
-    ngx_int_t                rc;
-    ngx_buf_t               *b, **prev;
-    ngx_chain_t             *cl;
-    ngx_http_request_t      *r;
-    ngx_http_fastcgi_ctx_t  *f;
+    u_char                       *m, *msg;
+    ngx_int_t                     rc;
+    ngx_buf_t                    *b, **prev;
+    ngx_chain_t                  *cl;
+    ngx_http_request_t           *r;
+    ngx_http_fastcgi_ctx_t       *f;
+    ngx_http_fastcgi_loc_conf_t  *flcf;
 
     if (buf->pos == buf->last) {
         return NGX_OK;
@@ -1589,6 +1622,7 @@ ngx_http_fastcgi_input_filter(ngx_event_pipe_t *p, ngx_buf_t *buf)
 
     r = p->input_ctx;
     f = ngx_http_get_module_ctx(r, ngx_http_fastcgi_module);
+    flcf = ngx_http_get_module_loc_conf(r, ngx_http_fastcgi_module);
 
     b = NULL;
     prev = &buf->shadow;
@@ -1611,7 +1645,10 @@ ngx_http_fastcgi_input_filter(ngx_event_pipe_t *p, ngx_buf_t *buf)
 
             if (f->type == NGX_HTTP_FASTCGI_STDOUT && f->length == 0) {
                 f->state = ngx_http_fastcgi_st_version;
-                p->upstream_done = 1;
+
+                if (!flcf->keep_conn) {
+                    p->upstream_done = 1;
+                }
 
                 ngx_log_debug0(NGX_LOG_DEBUG_HTTP, p->log, 0,
                                "http fastcgi closed stdout");
@@ -1623,6 +1660,10 @@ ngx_http_fastcgi_input_filter(ngx_event_pipe_t *p, ngx_buf_t *buf)
                 f->state = ngx_http_fastcgi_st_version;
                 p->upstream_done = 1;
 
+                if (flcf->keep_conn) {
+                    r->upstream->keepalive = 1;
+                }
+
                 ngx_log_debug0(NGX_LOG_DEBUG_HTTP, p->log, 0,
                                "http fastcgi sent end request");
 
@@ -1703,8 +1744,10 @@ ngx_http_fastcgi_input_filter(ngx_event_pipe_t *p, ngx_buf_t *buf)
         }
 
         if (p->free) {
-            b = p->free->buf;
-            p->free = p->free->next;
+            cl = p->free;
+            b = cl->buf;
+            p->free = cl->next;
+            ngx_free_chain(p->pool, cl);
 
         } else {
             b = ngx_alloc_buf(p->pool);
@@ -1781,6 +1824,23 @@ ngx_http_fastcgi_input_filter(ngx_event_pipe_t *p, ngx_buf_t *buf)
 
     }
 
+    if (flcf->keep_conn) {
+
+        /* set p->length, minimal amount of data we want to see */
+
+        if (f->state < ngx_http_fastcgi_st_data) {
+            p->length = 1;
+
+        } else if (f->state == ngx_http_fastcgi_st_padding) {
+            p->length = f->padding;
+
+        } else {
+            /* ngx_http_fastcgi_st_data */
+
+            p->length = f->length;
+        }
+    }
+
     if (b) {
         b->shadow = buf;
         b->last_shadow = 1;
@@ -2011,6 +2071,8 @@ ngx_http_fastcgi_create_loc_conf(ngx_conf_t *cf)
 
     conf->catch_stderr = NGX_CONF_UNSET_PTR;
 
+    conf->keep_conn = NGX_CONF_UNSET;
+
     ngx_str_set(&conf->upstream.module, "fastcgi");
 
     return conf;
@@ -2254,6 +2316,8 @@ ngx_http_fastcgi_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child)
 
     ngx_conf_merge_ptr_value(conf->catch_stderr, prev->catch_stderr, NULL);
 
+    ngx_conf_merge_value(conf->keep_conn, prev->keep_conn, 0);
+
 
     ngx_conf_merge_str_value(conf->index, prev->index, "");
 
diff --git a/src/http/modules/ngx_http_gzip_filter_module.c b/src/http/modules/ngx_http_gzip_filter_module.c
index d624e36ff..18824059a 100644
--- a/src/http/modules/ngx_http_gzip_filter_module.c
+++ b/src/http/modules/ngx_http_gzip_filter_module.c
@@ -378,7 +378,7 @@ ngx_http_gzip_body_filter(ngx_http_request_t *r, ngx_chain_t *in)
 
         cl = NULL;
 
-        ngx_chain_update_chains(&ctx->free, &ctx->busy, &cl,
+        ngx_chain_update_chains(r->pool, &ctx->free, &ctx->busy, &cl,
                                 (ngx_buf_tag_t) &ngx_http_gzip_filter_module);
         ctx->nomem = 0;
     }
@@ -448,7 +448,7 @@ ngx_http_gzip_body_filter(ngx_http_request_t *r, ngx_chain_t *in)
 
         ngx_http_gzip_filter_free_copy_buf(r, ctx);
 
-        ngx_chain_update_chains(&ctx->free, &ctx->busy, &ctx->out,
+        ngx_chain_update_chains(r->pool, &ctx->free, &ctx->busy, &ctx->out,
                                 (ngx_buf_tag_t) &ngx_http_gzip_filter_module);
         ctx->last_out = &ctx->out;
 
diff --git a/src/http/modules/ngx_http_headers_filter_module.c b/src/http/modules/ngx_http_headers_filter_module.c
index 1d409582c..c3f74ae19 100644
--- a/src/http/modules/ngx_http_headers_filter_module.c
+++ b/src/http/modules/ngx_http_headers_filter_module.c
@@ -507,7 +507,7 @@ ngx_http_headers_expires(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
         minus = 0;
 
         if (hcf->expires == NGX_HTTP_EXPIRES_MODIFIED) {
-            return "daily time can not be used with \"modified\" parameter";
+            return "daily time cannot be used with \"modified\" parameter";
         }
 
         hcf->expires = NGX_HTTP_EXPIRES_DAILY;
diff --git a/src/http/modules/ngx_http_log_module.c b/src/http/modules/ngx_http_log_module.c
index b2bfbf477..9728d5411 100644
--- a/src/http/modules/ngx_http_log_module.c
+++ b/src/http/modules/ngx_http_log_module.c
@@ -960,7 +960,7 @@ buffer:
 
         if (log->script) {
             ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
-                               "buffered logs can not have variables in name");
+                               "buffered logs cannot have variables in name");
             return NGX_CONF_ERROR;
         }
 
diff --git a/src/http/modules/ngx_http_memcached_module.c b/src/http/modules/ngx_http_memcached_module.c
index 745f73aa5..dbe0fe838 100644
--- a/src/http/modules/ngx_http_memcached_module.c
+++ b/src/http/modules/ngx_http_memcached_module.c
@@ -344,8 +344,8 @@ found:
 
         while (*p && *p++ != CR) { /* void */ }
 
-        r->headers_out.content_length_n = ngx_atoof(len, p - len - 1);
-        if (r->headers_out.content_length_n == -1) {
+        u->headers_in.content_length_n = ngx_atoof(len, p - len - 1);
+        if (u->headers_in.content_length_n == -1) {
             ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                           "memcached sent invalid length in response \"%V\" "
                           "for key \"%V\"",
@@ -366,6 +366,7 @@ found:
 
         u->headers_in.status_n = 404;
         u->state->status = 404;
+        u->keepalive = 1;
 
         return NGX_OK;
     }
@@ -407,7 +408,7 @@ ngx_http_memcached_filter(void *data, ssize_t bytes)
     u = ctx->request->upstream;
     b = &u->buffer;
 
-    if (u->length == ctx->rest) {
+    if (u->length == (ssize_t) ctx->rest) {
 
         if (ngx_strncmp(b->last,
                    ngx_http_memcached_end + NGX_HTTP_MEMCACHED_END - ctx->rest,
@@ -426,6 +427,10 @@ ngx_http_memcached_filter(void *data, ssize_t bytes)
         u->length -= bytes;
         ctx->rest -= bytes;
 
+        if (u->length == 0) {
+            u->keepalive = 1;
+        }
+
         return NGX_OK;
     }
 
@@ -463,6 +468,13 @@ ngx_http_memcached_filter(void *data, ssize_t bytes)
     if (ngx_strncmp(last, ngx_http_memcached_end, b->last - last) != 0) {
         ngx_log_error(NGX_LOG_ERR, ctx->request->connection->log, 0,
                       "memcached sent invalid trailer");
+
+        b->last = last;
+        cl->buf->last = last;
+        u->length = 0;
+        ctx->rest = 0;
+
+        return NGX_OK;
     }
 
     ctx->rest -= b->last - last;
@@ -470,6 +482,10 @@ ngx_http_memcached_filter(void *data, ssize_t bytes)
     cl->buf->last = last;
     u->length = ctx->rest;
 
+    if (u->length == 0) {
+        u->keepalive = 1;
+    }
+
     return NGX_OK;
 }
 
diff --git a/src/http/modules/ngx_http_mp4_module.c b/src/http/modules/ngx_http_mp4_module.c
index fc21ec410..9a3362e8d 100644
--- a/src/http/modules/ngx_http_mp4_module.c
+++ b/src/http/modules/ngx_http_mp4_module.c
@@ -32,8 +32,10 @@
 #define NGX_HTTP_MP4_STSZ_DATA    21
 #define NGX_HTTP_MP4_STCO_ATOM    22
 #define NGX_HTTP_MP4_STCO_DATA    23
+#define NGX_HTTP_MP4_CO64_ATOM    24
+#define NGX_HTTP_MP4_CO64_DATA    25
 
-#define NGX_HTTP_MP4_LAST_ATOM    NGX_HTTP_MP4_STCO_DATA
+#define NGX_HTTP_MP4_LAST_ATOM    NGX_HTTP_MP4_CO64_DATA
 
 
 typedef struct {
@@ -61,7 +63,7 @@ typedef struct {
     ngx_uint_t            start_sample;
     ngx_uint_t            start_chunk;
     ngx_uint_t            chunk_samples;
-    ngx_uint_t            chunk_samples_size;
+    uint64_t              chunk_samples_size;
     off_t                 start_offset;
 
     size_t                tkhd_size;
@@ -96,8 +98,10 @@ typedef struct {
     ngx_buf_t             stsc_data_buf;
     ngx_buf_t             stsz_atom_buf;
     ngx_buf_t             stsz_data_buf;
-    ngx_buf_t             tsco_atom_buf;
-    ngx_buf_t             tsco_data_buf;
+    ngx_buf_t             stco_atom_buf;
+    ngx_buf_t             stco_data_buf;
+    ngx_buf_t             co64_atom_buf;
+    ngx_buf_t             co64_data_buf;
 
     ngx_mp4_stsc_entry_t  stsc_chunk_entry;
 } ngx_http_mp4_trak_t;
@@ -268,6 +272,12 @@ static ngx_int_t ngx_http_mp4_update_stco_atom(ngx_http_mp4_file_t *mp4,
     ngx_http_mp4_trak_t *trak);
 static void ngx_http_mp4_adjust_stco_atom(ngx_http_mp4_file_t *mp4,
     ngx_http_mp4_trak_t *trak, int32_t adjustment);
+static ngx_int_t ngx_http_mp4_read_co64_atom(ngx_http_mp4_file_t *mp4,
+    uint64_t atom_data_size);
+static ngx_int_t ngx_http_mp4_update_co64_atom(ngx_http_mp4_file_t *mp4,
+    ngx_http_mp4_trak_t *trak);
+static void ngx_http_mp4_adjust_co64_atom(ngx_http_mp4_file_t *mp4,
+    ngx_http_mp4_trak_t *trak, off_t adjustment);
 static char *ngx_http_mp4(ngx_conf_t *cf, ngx_command_t *cmd, void *conf);
 static void *ngx_http_mp4_create_conf(ngx_conf_t *cf);
 static char *ngx_http_mp4_merge_conf(ngx_conf_t *cf, void *parent, void *child);
@@ -373,6 +383,7 @@ static ngx_http_mp4_atom_handler_t  ngx_http_mp4_stbl_atoms[] = {
     { "stsc", ngx_http_mp4_read_stsc_atom },
     { "stsz", ngx_http_mp4_read_stsz_atom },
     { "stco", ngx_http_mp4_read_stco_atom },
+    { "co64", ngx_http_mp4_read_co64_atom },
     { NULL, NULL }
 };
 
@@ -676,8 +687,15 @@ ngx_http_mp4_process(ngx_http_mp4_file_t *mp4)
 
         ngx_http_mp4_update_stsz_atom(mp4, &trak[i]);
 
-        if (ngx_http_mp4_update_stco_atom(mp4, &trak[i]) != NGX_OK) {
-            return NGX_ERROR;
+        if (trak[i].out[NGX_HTTP_MP4_CO64_DATA].buf) {
+            if (ngx_http_mp4_update_co64_atom(mp4, &trak[i]) != NGX_OK) {
+                return NGX_ERROR;
+            }
+
+        } else {
+            if (ngx_http_mp4_update_stco_atom(mp4, &trak[i]) != NGX_OK) {
+                return NGX_ERROR;
+            }
         }
 
         ngx_http_mp4_update_stbl_atom(mp4, &trak[i]);
@@ -721,7 +739,11 @@ ngx_http_mp4_process(ngx_http_mp4_file_t *mp4)
                    "mp4 adjustment:%D", adjustment);
 
     for (i = 0; i < mp4->trak.nelts; i++) {
-        ngx_http_mp4_adjust_stco_atom(mp4, &trak[i], (int32_t) adjustment);
+        if (trak[i].out[NGX_HTTP_MP4_CO64_DATA].buf) {
+            ngx_http_mp4_adjust_co64_atom(mp4, &trak[i], adjustment);
+        } else {
+            ngx_http_mp4_adjust_stco_atom(mp4, &trak[i], (int32_t) adjustment);
+        }
     }
 
     return NGX_OK;
@@ -1702,7 +1724,6 @@ ngx_http_mp4_read_stsd_atom(ngx_http_mp4_file_t *mp4, uint64_t atom_data_size)
 {
     u_char               *atom_header, *atom_table;
     size_t                atom_size;
-    uint32_t              entries;
     ngx_buf_t            *atom;
     ngx_mp4_stsd_atom_t  *stsd_atom;
     ngx_http_mp4_trak_t  *trak;
@@ -1718,10 +1739,9 @@ ngx_http_mp4_read_stsd_atom(ngx_http_mp4_file_t *mp4, uint64_t atom_data_size)
     ngx_mp4_set_32value(stsd_atom->size, atom_size);
     ngx_mp4_set_atom_name(stsd_atom, 's', 't', 's', 'd');
 
-    entries = ngx_mp4_get_32value(stsd_atom->entries);
-
     if ((uint64_t) (sizeof(ngx_mp4_stsd_atom_t) - sizeof(ngx_mp4_atom_header_t))
-         > atom_data_size) {
+         > atom_data_size)
+    {
         ngx_log_error(NGX_LOG_ERR, mp4->file.log, 0,
                       "\"%s\" mp4 stsd atom too large",
                       mp4->file.name.data);
@@ -2497,7 +2517,7 @@ ngx_http_mp4_update_stsz_atom(ngx_http_mp4_file_t *mp4,
         }
 
         ngx_log_debug1(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
-                       "chunk samples sizes:%uD", trak->chunk_samples_size);
+                       "chunk samples sizes:%uL", trak->chunk_samples_size);
 
         atom_size = sizeof(ngx_mp4_stsz_atom_t) + (data->last - data->pos);
         trak->size += atom_size;
@@ -2554,12 +2574,12 @@ ngx_http_mp4_read_stco_atom(ngx_http_mp4_file_t *mp4, uint64_t atom_data_size)
     trak = ngx_mp4_last_trak(mp4);
     trak->chunks = entries;
 
-    atom = &trak->tsco_atom_buf;
+    atom = &trak->stco_atom_buf;
     atom->temporary = 1;
     atom->pos = atom_header;
     atom->last = atom_table;
 
-    data = &trak->tsco_data_buf;
+    data = &trak->stco_data_buf;
     data->temporary = 1;
     data->pos = atom_table;
     data->last = atom_end;
@@ -2648,6 +2668,142 @@ ngx_http_mp4_adjust_stco_atom(ngx_http_mp4_file_t *mp4,
 }
 
 
+typedef struct {
+    u_char    size[4];
+    u_char    name[4];
+    u_char    version[1];
+    u_char    flags[3];
+    u_char    entries[4];
+} ngx_mp4_co64_atom_t;
+
+
+static ngx_int_t
+ngx_http_mp4_read_co64_atom(ngx_http_mp4_file_t *mp4, uint64_t atom_data_size)
+{
+    u_char               *atom_header, *atom_table, *atom_end;
+    uint32_t              entries;
+    ngx_buf_t            *atom, *data;
+    ngx_mp4_co64_atom_t  *co64_atom;
+    ngx_http_mp4_trak_t  *trak;
+
+    /* chunk offsets atom */
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0, "mp4 co64 atom");
+
+    atom_header = ngx_mp4_atom_header(mp4);
+    co64_atom = (ngx_mp4_co64_atom_t *) atom_header;
+    ngx_mp4_set_atom_name(co64_atom, 'c', 'o', '6', '4');
+
+    entries = ngx_mp4_get_32value(co64_atom->entries);
+
+    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0, "chunks:%uD", entries);
+
+    atom_table = atom_header + sizeof(ngx_mp4_co64_atom_t);
+    atom_end = atom_table + entries * sizeof(uint64_t);
+
+    if ((uint64_t) (atom_end - co64_atom->version) > atom_data_size) {
+        ngx_log_error(NGX_LOG_ERR, mp4->file.log, 0,
+                      "\"%s\" mp4 co64 atom too large", mp4->file.name.data);
+        return NGX_ERROR;
+    }
+
+    trak = ngx_mp4_last_trak(mp4);
+    trak->chunks = entries;
+
+    atom = &trak->co64_atom_buf;
+    atom->temporary = 1;
+    atom->pos = atom_header;
+    atom->last = atom_table;
+
+    data = &trak->co64_data_buf;
+    data->temporary = 1;
+    data->pos = atom_table;
+    data->last = atom_end;
+
+    trak->out[NGX_HTTP_MP4_CO64_ATOM].buf = atom;
+    trak->out[NGX_HTTP_MP4_CO64_DATA].buf = data;
+
+    ngx_mp4_atom_next(mp4, atom_data_size);
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t
+ngx_http_mp4_update_co64_atom(ngx_http_mp4_file_t *mp4,
+    ngx_http_mp4_trak_t *trak)
+{
+    size_t                atom_size;
+    ngx_buf_t            *atom, *data;
+    ngx_mp4_co64_atom_t  *co64_atom;
+
+    /*
+     * mdia.minf.stbl.co64 updating requires trak->start_chunk
+     * from mdia.minf.stbl.stsc which depends on value from mdia.mdhd
+     * atom which may reside after mdia.minf
+     */
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                   "mp4 co64 atom update");
+
+    data = trak->out[NGX_HTTP_MP4_CO64_DATA].buf;
+
+    if (data == NULL) {
+        ngx_log_error(NGX_LOG_ERR, mp4->file.log, 0,
+                      "no mp4 co64 atoms were found in \"%s\"",
+                      mp4->file.name.data);
+        return NGX_ERROR;
+    }
+
+    data->pos += trak->start_chunk * sizeof(uint64_t);
+    atom_size = sizeof(ngx_mp4_co64_atom_t) + (data->last - data->pos);
+    trak->size += atom_size;
+
+    trak->start_offset = ngx_mp4_get_64value(data->pos);
+    trak->start_offset += trak->chunk_samples_size;
+    ngx_mp4_set_64value(data->pos, trak->start_offset);
+
+    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                   "start chunk offset:%uL", trak->start_offset);
+
+    atom = trak->out[NGX_HTTP_MP4_CO64_ATOM].buf;
+    co64_atom = (ngx_mp4_co64_atom_t *) atom->pos;
+
+    ngx_mp4_set_32value(co64_atom->size, atom_size);
+    ngx_mp4_set_32value(co64_atom->entries, trak->chunks - trak->start_chunk);
+
+    return NGX_OK;
+}
+
+
+static void
+ngx_http_mp4_adjust_co64_atom(ngx_http_mp4_file_t *mp4,
+    ngx_http_mp4_trak_t *trak, off_t adjustment)
+{
+    uint64_t    offset, *entry, *end;
+    ngx_buf_t  *data;
+
+    /*
+     * moov.trak.mdia.minf.stbl.co64 adjustment requires
+     * minimal start offset of all traks and new moov atom size
+     */
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
+                   "mp4 co64 atom adjustment");
+
+    data = trak->out[NGX_HTTP_MP4_CO64_DATA].buf;
+    entry = (uint64_t *) data->pos;
+    end = (uint64_t *) data->last;
+
+    while (entry < end) {
+        offset = ngx_mp4_get_64value(entry);
+        offset += adjustment;
+        ngx_mp4_set_64value(entry, offset);
+        entry++;
+    }
+}
+
+
 static char *
 ngx_http_mp4(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
 {
diff --git a/src/http/modules/ngx_http_proxy_module.c b/src/http/modules/ngx_http_proxy_module.c
index 902cfb8f2..88ee42472 100644
--- a/src/http/modules/ngx_http_proxy_module.c
+++ b/src/http/modules/ngx_http_proxy_module.c
@@ -71,6 +71,8 @@ typedef struct {
 
     ngx_flag_t                     redirect;
 
+    ngx_uint_t                     http_version;
+
     ngx_uint_t                     headers_hash_max_size;
     ngx_uint_t                     headers_hash_bucket_size;
 } ngx_http_proxy_loc_conf_t;
@@ -80,6 +82,12 @@ typedef struct {
     ngx_http_status_t              status;
     ngx_http_proxy_vars_t          vars;
     size_t                         internal_body_length;
+
+    ngx_uint_t                     state;
+    off_t                          size;
+    off_t                          length;
+
+    ngx_uint_t                     head;  /* unsigned  head:1 */
 } ngx_http_proxy_ctx_t;
 
 
@@ -92,6 +100,15 @@ static ngx_int_t ngx_http_proxy_create_request(ngx_http_request_t *r);
 static ngx_int_t ngx_http_proxy_reinit_request(ngx_http_request_t *r);
 static ngx_int_t ngx_http_proxy_process_status_line(ngx_http_request_t *r);
 static ngx_int_t ngx_http_proxy_process_header(ngx_http_request_t *r);
+static ngx_int_t ngx_http_proxy_input_filter_init(void *data);
+static ngx_int_t ngx_http_proxy_copy_filter(ngx_event_pipe_t *p,
+    ngx_buf_t *buf);
+static ngx_int_t ngx_http_proxy_chunked_filter(ngx_event_pipe_t *p,
+    ngx_buf_t *buf);
+static ngx_int_t ngx_http_proxy_non_buffered_copy_filter(void *data,
+    ssize_t bytes);
+static ngx_int_t ngx_http_proxy_non_buffered_chunked_filter(void *data,
+    ssize_t bytes);
 static void ngx_http_proxy_abort_request(ngx_http_request_t *r);
 static void ngx_http_proxy_finalize_request(ngx_http_request_t *r,
     ngx_int_t rc);
@@ -157,6 +174,13 @@ static ngx_conf_bitmask_t  ngx_http_proxy_next_upstream_masks[] = {
 };
 
 
+static ngx_conf_enum_t  ngx_http_proxy_http_version[] = {
+    { ngx_string("1.0"), NGX_HTTP_VERSION_10 },
+    { ngx_string("1.1"), NGX_HTTP_VERSION_11 },
+    { ngx_null_string, 0 }
+};
+
+
 ngx_module_t  ngx_http_proxy_module;
 
 
@@ -432,6 +456,13 @@ static ngx_command_t  ngx_http_proxy_commands[] = {
       offsetof(ngx_http_proxy_loc_conf_t, upstream.ignore_headers),
       &ngx_http_upstream_ignore_headers_masks },
 
+    { ngx_string("proxy_http_version"),
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
+      ngx_conf_set_enum_slot,
+      NGX_HTTP_LOC_CONF_OFFSET,
+      offsetof(ngx_http_proxy_loc_conf_t, http_version),
+      &ngx_http_proxy_http_version },
+
 #if (NGX_HTTP_SSL)
 
     { ngx_string("proxy_ssl_session_reuse"),
@@ -479,6 +510,7 @@ ngx_module_t  ngx_http_proxy_module = {
 
 
 static char  ngx_http_proxy_version[] = " HTTP/1.0" CRLF;
+static char  ngx_http_proxy_version_11[] = " HTTP/1.1" CRLF;
 
 
 static ngx_keyval_t  ngx_http_proxy_headers[] = {
@@ -486,6 +518,7 @@ static ngx_keyval_t  ngx_http_proxy_headers[] = {
     { ngx_string("Connection"), ngx_string("close") },
     { ngx_string("Keep-Alive"), ngx_string("") },
     { ngx_string("Expect"), ngx_string("") },
+    { ngx_string("Upgrade"), ngx_string("") },
     { ngx_null_string, ngx_null_string }
 };
 
@@ -610,7 +643,12 @@ ngx_http_proxy_handler(ngx_http_request_t *r)
         return NGX_HTTP_INTERNAL_SERVER_ERROR;
     }
 
-    u->pipe->input_filter = ngx_event_pipe_copy_input_filter;
+    u->pipe->input_filter = ngx_http_proxy_copy_filter;
+    u->pipe->input_ctx = r;
+
+    u->input_filter_init = ngx_http_proxy_input_filter_init;
+    u->input_filter = ngx_http_proxy_non_buffered_copy_filter;
+    u->input_filter_ctx = r;
 
     u->accel = 1;
 
@@ -866,14 +904,20 @@ ngx_http_proxy_create_request(ngx_http_request_t *r)
         method.len++;
     }
 
+    ctx = ngx_http_get_module_ctx(r, ngx_http_proxy_module);
+
+    if (method.len == 5
+        && ngx_strncasecmp(method.data, (u_char *) "HEAD ", 5) == 0)
+    {
+        ctx->head = 1;
+    }
+
     len = method.len + sizeof(ngx_http_proxy_version) - 1 + sizeof(CRLF) - 1;
 
     escape = 0;
     loc_len = 0;
     unparsed_uri = 0;
 
-    ctx = ngx_http_get_module_ctx(r, ngx_http_proxy_module);
-
     if (plcf->proxy_lengths) {
         uri_len = ctx->vars.uri.len;
 
@@ -1009,8 +1053,14 @@ ngx_http_proxy_create_request(ngx_http_request_t *r)
 
     u->uri.len = b->last - u->uri.data;
 
-    b->last = ngx_cpymem(b->last, ngx_http_proxy_version,
-                         sizeof(ngx_http_proxy_version) - 1);
+    if (plcf->http_version == NGX_HTTP_VERSION_11) {
+        b->last = ngx_cpymem(b->last, ngx_http_proxy_version_11,
+                             sizeof(ngx_http_proxy_version_11) - 1);
+
+    } else {
+        b->last = ngx_cpymem(b->last, ngx_http_proxy_version,
+                             sizeof(ngx_http_proxy_version) - 1);
+    }
 
     ngx_memzero(&e, sizeof(ngx_http_script_engine_t));
 
@@ -1158,8 +1208,11 @@ ngx_http_proxy_reinit_request(ngx_http_request_t *r)
     ctx->status.count = 0;
     ctx->status.start = NULL;
     ctx->status.end = NULL;
+    ctx->state = 0;
 
     r->upstream->process_header = ngx_http_proxy_process_status_line;
+    r->upstream->pipe->input_filter = ngx_http_proxy_copy_filter;
+    r->upstream->input_filter = ngx_http_proxy_non_buffered_copy_filter;
     r->state = 0;
 
     return NGX_OK;
@@ -1210,6 +1263,7 @@ ngx_http_proxy_process_status_line(ngx_http_request_t *r)
 
         r->http_version = NGX_HTTP_VERSION_9;
         u->state->status = NGX_HTTP_OK;
+        u->headers_in.connection_close = 1;
 
         return NGX_OK;
     }
@@ -1234,6 +1288,10 @@ ngx_http_proxy_process_status_line(ngx_http_request_t *r)
                    "http proxy status %ui \"%V\"",
                    u->headers_in.status_n, &u->headers_in.status_line);
 
+    if (ctx->status.http_version < NGX_HTTP_VERSION_11) {
+        u->headers_in.connection_close = 1;
+    }
+
     u->process_header = ngx_http_proxy_process_header;
 
     return ngx_http_proxy_process_header(r);
@@ -1245,6 +1303,8 @@ ngx_http_proxy_process_header(ngx_http_request_t *r)
 {
     ngx_int_t                       rc;
     ngx_table_elt_t                *h;
+    ngx_http_upstream_t            *u;
+    ngx_http_proxy_ctx_t           *ctx;
     ngx_http_upstream_header_t     *hh;
     ngx_http_upstream_main_conf_t  *umcf;
 
@@ -1340,6 +1400,30 @@ ngx_http_proxy_process_header(ngx_http_request_t *r)
                 h->lowcase_key = (u_char *) "date";
             }
 
+            /* clear content length if response is chunked */
+
+            u = r->upstream;
+
+            if (u->headers_in.chunked) {
+                u->headers_in.content_length_n = -1;
+            }
+
+            /*
+             * set u->keepalive if response has no body; this allows to keep
+             * connections alive in case of r->header_only or X-Accel-Redirect
+             */
+
+            ctx = ngx_http_get_module_ctx(r, ngx_http_proxy_module);
+
+            if (u->headers_in.status_n == NGX_HTTP_NO_CONTENT
+                || u->headers_in.status_n == NGX_HTTP_NOT_MODIFIED
+                || ctx->head
+                || (!u->headers_in.chunked
+                    && u->headers_in.content_length_n == 0))
+            {
+                u->keepalive = !u->headers_in.connection_close;
+            }
+
             return NGX_OK;
         }
 
@@ -1357,6 +1441,690 @@ ngx_http_proxy_process_header(ngx_http_request_t *r)
 }
 
 
+static ngx_int_t
+ngx_http_proxy_input_filter_init(void *data)
+{
+    ngx_http_request_t    *r = data;
+    ngx_http_upstream_t   *u;
+    ngx_http_proxy_ctx_t  *ctx;
+
+    u = r->upstream;
+    ctx = ngx_http_get_module_ctx(r, ngx_http_proxy_module);
+
+    ngx_log_debug4(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                   "http proxy filter init s:%d h:%d c:%d l:%O",
+                   u->headers_in.status_n, ctx->head, u->headers_in.chunked,
+                   u->headers_in.content_length_n);
+
+    /* as per RFC2616, 4.4 Message Length */
+
+    if (u->headers_in.status_n == NGX_HTTP_NO_CONTENT
+        || u->headers_in.status_n == NGX_HTTP_NOT_MODIFIED
+        || ctx->head)
+    {
+        /* 1xx, 204, and 304 and replies to HEAD requests */
+        /* no 1xx since we don't send Expect and Upgrade */
+
+        u->pipe->length = 0;
+        u->length = 0;
+        u->keepalive = !u->headers_in.connection_close;
+
+    } else if (u->headers_in.chunked) {
+        /* chunked */
+
+        u->pipe->input_filter = ngx_http_proxy_chunked_filter;
+        u->pipe->length = 3; /* "0" LF LF */
+
+        u->input_filter = ngx_http_proxy_non_buffered_chunked_filter;
+        u->length = -1;
+
+    } else if (u->headers_in.content_length_n == 0) {
+        /* empty body: special case as filter won't be called */
+
+        u->pipe->length = 0;
+        u->length = 0;
+        u->keepalive = !u->headers_in.connection_close;
+
+    } else {
+        /* content length or connection close */
+
+        u->pipe->length = u->headers_in.content_length_n;
+        u->length = u->headers_in.content_length_n;
+    }
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t
+ngx_http_proxy_copy_filter(ngx_event_pipe_t *p, ngx_buf_t *buf)
+{
+    ngx_buf_t           *b;
+    ngx_chain_t         *cl;
+    ngx_http_request_t  *r;
+
+    if (buf->pos == buf->last) {
+        return NGX_OK;
+    }
+
+    if (p->free) {
+        cl = p->free;
+        b = cl->buf;
+        p->free = cl->next;
+        ngx_free_chain(p->pool, cl);
+
+    } else {
+        b = ngx_alloc_buf(p->pool);
+        if (b == NULL) {
+            return NGX_ERROR;
+        }
+    }
+
+    ngx_memcpy(b, buf, sizeof(ngx_buf_t));
+    b->shadow = buf;
+    b->tag = p->tag;
+    b->last_shadow = 1;
+    b->recycled = 1;
+    buf->shadow = b;
+
+    cl = ngx_alloc_chain_link(p->pool);
+    if (cl == NULL) {
+        return NGX_ERROR;
+    }
+
+    cl->buf = b;
+    cl->next = NULL;
+
+    ngx_log_debug1(NGX_LOG_DEBUG_EVENT, p->log, 0, "input buf #%d", b->num);
+
+    if (p->in) {
+        *p->last_in = cl;
+    } else {
+        p->in = cl;
+    }
+    p->last_in = &cl->next;
+
+    if (p->length == -1) {
+        return NGX_OK;
+    }
+
+    p->length -= b->last - b->pos;
+
+    if (p->length == 0) {
+        r = p->input_ctx;
+        p->upstream_done = 1;
+        r->upstream->keepalive = !r->upstream->headers_in.connection_close;
+
+    } else if (p->length < 0) {
+        r = p->input_ctx;
+        p->upstream_done = 1;
+
+        ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
+                      "upstream sent too many data");
+    }
+
+    return NGX_OK;
+}
+
+
+static ngx_inline ngx_int_t
+ngx_http_proxy_parse_chunked(ngx_http_request_t *r, ngx_buf_t *buf)
+{
+    u_char                *pos, ch, c;
+    ngx_int_t              rc;
+    ngx_http_proxy_ctx_t  *ctx;
+    enum {
+        sw_chunk_start = 0,
+        sw_chunk_size,
+        sw_chunk_extension,
+        sw_chunk_extension_almost_done,
+        sw_chunk_data,
+        sw_after_data,
+        sw_after_data_almost_done,
+        sw_last_chunk_extension,
+        sw_last_chunk_extension_almost_done,
+        sw_trailer,
+        sw_trailer_almost_done,
+        sw_trailer_header,
+        sw_trailer_header_almost_done
+    } state;
+
+    ctx = ngx_http_get_module_ctx(r, ngx_http_proxy_module);
+    state = ctx->state;
+
+    if (state == sw_chunk_data && ctx->size == 0) {
+        state = sw_after_data;
+    }
+
+    rc = NGX_AGAIN;
+
+    for (pos = buf->pos; pos < buf->last; pos++) {
+
+        ch = *pos;
+
+        ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                       "http proxy chunked byte: %02Xd s:%d", ch, state);
+
+        switch (state) {
+
+        case sw_chunk_start:
+            if (ch >= '0' && ch <= '9') {
+                state = sw_chunk_size;
+                ctx->size = ch - '0';
+                break;
+            }
+
+            c = (u_char) (ch | 0x20);
+
+            if (c >= 'a' && c <= 'f') {
+                state = sw_chunk_size;
+                ctx->size = c - 'a' + 10;
+                break;
+            }
+
+            goto invalid;
+
+        case sw_chunk_size:
+            if (ch >= '0' && ch <= '9') {
+                ctx->size = ctx->size * 16 + (ch - '0');
+                break;
+            }
+
+            c = (u_char) (ch | 0x20);
+
+            if (c >= 'a' && c <= 'f') {
+                ctx->size = ctx->size * 16 + (c - 'a' + 10);
+                break;
+            }
+
+            if (ctx->size == 0) {
+
+                switch (ch) {
+                case CR:
+                    state = sw_last_chunk_extension_almost_done;
+                    break;
+                case LF:
+                    state = sw_trailer;
+                    break;
+                case ';':
+                    state = sw_last_chunk_extension;
+                    break;
+                default:
+                    goto invalid;
+                }
+
+                break;
+            }
+
+            switch (ch) {
+            case CR:
+                state = sw_chunk_extension_almost_done;
+                break;
+            case LF:
+                state = sw_chunk_data;
+                break;
+            case ';':
+                state = sw_chunk_extension;
+                break;
+            default:
+                goto invalid;
+            }
+
+            break;
+
+        case sw_chunk_extension:
+            switch (ch) {
+            case CR:
+                state = sw_chunk_extension_almost_done;
+                break;
+            case LF:
+                state = sw_chunk_data;
+            }
+            break;
+
+        case sw_chunk_extension_almost_done:
+            if (ch == LF) {
+                state = sw_chunk_data;
+                break;
+            }
+            goto invalid;
+
+        case sw_chunk_data:
+            rc = NGX_OK;
+            goto data;
+
+        case sw_after_data:
+            switch (ch) {
+            case CR:
+                state = sw_after_data_almost_done;
+                break;
+            case LF:
+                state = sw_chunk_start;
+            }
+            break;
+
+        case sw_after_data_almost_done:
+            if (ch == LF) {
+                state = sw_chunk_start;
+                break;
+            }
+            goto invalid;
+
+        case sw_last_chunk_extension:
+            switch (ch) {
+            case CR:
+                state = sw_last_chunk_extension_almost_done;
+                break;
+            case LF:
+                state = sw_trailer;
+            }
+            break;
+
+        case sw_last_chunk_extension_almost_done:
+            if (ch == LF) {
+                state = sw_trailer;
+                break;
+            }
+            goto invalid;
+
+        case sw_trailer:
+            switch (ch) {
+            case CR:
+                state = sw_trailer_almost_done;
+                break;
+            case LF:
+                goto done;
+            default:
+                state = sw_trailer_header;
+            }
+            break;
+
+        case sw_trailer_almost_done:
+            if (ch == LF) {
+                goto done;
+            }
+            goto invalid;
+
+        case sw_trailer_header:
+            switch (ch) {
+            case CR:
+                state = sw_trailer_header_almost_done;
+                break;
+            case LF:
+                state = sw_trailer;
+            }
+            break;
+
+        case sw_trailer_header_almost_done:
+            if (ch == LF) {
+                state = sw_trailer;
+                break;
+            }
+            goto invalid;
+
+        }
+    }
+
+data:
+
+    ctx->state = state;
+    buf->pos = pos;
+
+    switch (state) {
+
+    case sw_chunk_start:
+        ctx->length = 3 /* "0" LF LF */;
+        break;
+    case sw_chunk_size:
+        ctx->length = 2 /* LF LF */
+                      + (ctx->size ? ctx->size + 4 /* LF "0" LF LF */ : 0);
+        break;
+    case sw_chunk_extension:
+    case sw_chunk_extension_almost_done:
+        ctx->length = 1 /* LF */ + ctx->size + 4 /* LF "0" LF LF */;
+        break;
+    case sw_chunk_data:
+        ctx->length = ctx->size + 4 /* LF "0" LF LF */;
+        break;
+    case sw_after_data:
+    case sw_after_data_almost_done:
+        ctx->length = 4 /* LF "0" LF LF */;
+        break;
+    case sw_last_chunk_extension:
+    case sw_last_chunk_extension_almost_done:
+        ctx->length = 2 /* LF LF */;
+        break;
+    case sw_trailer:
+    case sw_trailer_almost_done:
+        ctx->length = 1 /* LF */;
+        break;
+    case sw_trailer_header:
+    case sw_trailer_header_almost_done:
+        ctx->length = 2 /* LF LF */;
+        break;
+
+    }
+
+    return rc;
+
+done:
+
+    return NGX_DONE;
+
+invalid:
+
+    ngx_log_error(NGX_LOG_ALERT, r->connection->log, 0,
+                  "upstream sent invalid chunked response");
+
+    return NGX_ERROR;
+}
+
+
+static ngx_int_t
+ngx_http_proxy_chunked_filter(ngx_event_pipe_t *p, ngx_buf_t *buf)
+{
+    ngx_int_t              rc;
+    ngx_buf_t             *b, **prev;
+    ngx_chain_t           *cl;
+    ngx_http_request_t    *r;
+    ngx_http_proxy_ctx_t  *ctx;
+
+    if (buf->pos == buf->last) {
+        return NGX_OK;
+    }
+
+    r = p->input_ctx;
+    ctx = ngx_http_get_module_ctx(r, ngx_http_proxy_module);
+
+    b = NULL;
+    prev = &buf->shadow;
+
+    for ( ;; ) {
+
+        rc = ngx_http_proxy_parse_chunked(r, buf);
+
+        if (rc == NGX_OK) {
+
+            /* a chunk has been parsed successfully */
+
+            if (p->free) {
+                cl = p->free;
+                b = cl->buf;
+                p->free = cl->next;
+                ngx_free_chain(p->pool, cl);
+
+            } else {
+                b = ngx_alloc_buf(p->pool);
+                if (b == NULL) {
+                    return NGX_ERROR;
+                }
+            }
+
+            ngx_memzero(b, sizeof(ngx_buf_t));
+
+            b->pos = buf->pos;
+            b->start = buf->start;
+            b->end = buf->end;
+            b->tag = p->tag;
+            b->temporary = 1;
+            b->recycled = 1;
+
+            *prev = b;
+            prev = &b->shadow;
+
+            cl = ngx_alloc_chain_link(p->pool);
+            if (cl == NULL) {
+                return NGX_ERROR;
+            }
+
+            cl->buf = b;
+            cl->next = NULL;
+
+            if (p->in) {
+                *p->last_in = cl;
+            } else {
+                p->in = cl;
+            }
+            p->last_in = &cl->next;
+
+            /* STUB */ b->num = buf->num;
+
+            ngx_log_debug2(NGX_LOG_DEBUG_EVENT, p->log, 0,
+                           "input buf #%d %p", b->num, b->pos);
+
+            if (buf->last - buf->pos >= ctx->size) {
+
+                buf->pos += ctx->size;
+                b->last = buf->pos;
+                ctx->size = 0;
+
+                continue;
+            }
+
+            ctx->size -= buf->last - buf->pos;
+            buf->pos = buf->last;
+            b->last = buf->last;
+
+            continue;
+        }
+
+        if (rc == NGX_DONE) {
+
+            /* a whole response has been parsed successfully */
+
+            p->upstream_done = 1;
+            r->upstream->keepalive = !r->upstream->headers_in.connection_close;
+
+            break;
+        }
+
+        if (rc == NGX_AGAIN) {
+
+            /* set p->length, minimal amount of data we want to see */
+
+            p->length = ctx->length;
+
+            break;
+        }
+
+        /* invalid response */
+
+        ngx_log_error(NGX_LOG_ALERT, r->connection->log, 0,
+                      "upstream sent invalid chunked response");
+
+        return NGX_ERROR;
+    }
+
+    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                   "http proxy chunked state %d, length %d",
+                   ctx->state, p->length);
+
+    if (b) {
+        b->shadow = buf;
+        b->last_shadow = 1;
+
+        ngx_log_debug2(NGX_LOG_DEBUG_EVENT, p->log, 0,
+                       "input buf %p %z", b->pos, b->last - b->pos);
+
+        return NGX_OK;
+    }
+
+    /* there is no data record in the buf, add it to free chain */
+
+    if (ngx_event_pipe_add_free_buf(p, buf) != NGX_OK) {
+        return NGX_ERROR;
+    }
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t
+ngx_http_proxy_non_buffered_copy_filter(void *data, ssize_t bytes)
+{
+    ngx_http_request_t   *r = data;
+
+    ngx_buf_t            *b;
+    ngx_chain_t          *cl, **ll;
+    ngx_http_upstream_t  *u;
+
+    u = r->upstream;
+
+    for (cl = u->out_bufs, ll = &u->out_bufs; cl; cl = cl->next) {
+        ll = &cl->next;
+    }
+
+    cl = ngx_chain_get_free_buf(r->pool, &u->free_bufs);
+    if (cl == NULL) {
+        return NGX_ERROR;
+    }
+
+    *ll = cl;
+
+    cl->buf->flush = 1;
+    cl->buf->memory = 1;
+
+    b = &u->buffer;
+
+    cl->buf->pos = b->last;
+    b->last += bytes;
+    cl->buf->last = b->last;
+    cl->buf->tag = u->output.tag;
+
+    if (u->length == -1) {
+        return NGX_OK;
+    }
+
+    u->length -= bytes;
+
+    if (u->length == 0) {
+        u->keepalive = !u->headers_in.connection_close;
+    }
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t
+ngx_http_proxy_non_buffered_chunked_filter(void *data, ssize_t bytes)
+{
+    ngx_http_request_t   *r = data;
+
+    ngx_int_t              rc;
+    ngx_buf_t             *b, *buf;
+    ngx_chain_t           *cl, **ll;
+    ngx_http_upstream_t   *u;
+    ngx_http_proxy_ctx_t  *ctx;
+
+    ctx = ngx_http_get_module_ctx(r, ngx_http_proxy_module);
+    u = r->upstream;
+    buf = &u->buffer;
+
+    buf->pos = buf->last;
+    buf->last += bytes;
+
+    for (cl = u->out_bufs, ll = &u->out_bufs; cl; cl = cl->next) {
+        ll = &cl->next;
+    }
+
+    for ( ;; ) {
+
+        rc = ngx_http_proxy_parse_chunked(r, buf);
+
+        if (rc == NGX_OK) {
+
+            /* a chunk has been parsed successfully */
+
+            cl = ngx_chain_get_free_buf(r->pool, &u->free_bufs);
+            if (cl == NULL) {
+                return NGX_ERROR;
+            }
+
+            *ll = cl;
+            ll = &cl->next;
+
+            b = cl->buf;
+
+            b->flush = 1;
+            b->memory = 1;
+
+            b->pos = buf->pos;
+            b->tag = u->output.tag;
+
+            if (buf->last - buf->pos >= ctx->size) {
+                buf->pos += ctx->size;
+                b->last = buf->pos;
+                ctx->size = 0;
+
+            } else {
+                ctx->size -= buf->last - buf->pos;
+                buf->pos = buf->last;
+                b->last = buf->last;
+            }
+
+            ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                           "http proxy out buf %p %z",
+                           b->pos, b->last - b->pos);
+
+            continue;
+        }
+
+        if (rc == NGX_DONE) {
+
+            /* a whole response has been parsed successfully */
+
+            u->keepalive = !u->headers_in.connection_close;
+            u->length = 0;
+
+            break;
+        }
+
+        if (rc == NGX_AGAIN) {
+            break;
+        }
+
+        /* invalid response */
+
+        ngx_log_error(NGX_LOG_ALERT, r->connection->log, 0,
+                      "upstream sent invalid chunked response");
+
+        return NGX_ERROR;
+    }
+
+    /* provide continuous buffer for subrequests in memory */
+
+    if (r->subrequest_in_memory) {
+
+        cl = u->out_bufs;
+
+        if (cl) {
+            buf->pos = cl->buf->pos;
+        }
+
+        buf->last = buf->pos;
+
+        for (cl = u->out_bufs; cl; cl = cl->next) {
+            ngx_log_debug3(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                           "http proxy in memory %p-%p %uz",
+                           cl->buf->pos, cl->buf->last, ngx_buf_size(cl->buf));
+
+            if (buf->last == cl->buf->pos) {
+                buf->last = cl->buf->last;
+                continue;
+            }
+
+            buf->last = ngx_movemem(buf->last, cl->buf->pos,
+                                    cl->buf->last - cl->buf->pos);
+
+            cl->buf->pos = buf->last - (cl->buf->last - cl->buf->pos);
+            cl->buf->last = buf->last;
+        }
+    }
+
+    return NGX_OK;
+}
+
+
 static void
 ngx_http_proxy_abort_request(ngx_http_request_t *r)
 {
@@ -1705,6 +2473,8 @@ ngx_http_proxy_create_loc_conf(ngx_conf_t *cf)
     conf->redirect = NGX_CONF_UNSET;
     conf->upstream.change_buffering = 1;
 
+    conf->http_version = NGX_CONF_UNSET_UINT;
+
     conf->headers_hash_max_size = NGX_CONF_UNSET_UINT;
     conf->headers_hash_bucket_size = NGX_CONF_UNSET_UINT;
 
@@ -2008,6 +2778,9 @@ ngx_http_proxy_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child)
     }
 #endif
 
+    ngx_conf_merge_uint_value(conf->http_version, prev->http_version,
+                              NGX_HTTP_VERSION_10);
+
     ngx_conf_merge_uint_value(conf->headers_hash_max_size,
                               prev->headers_hash_max_size, 512);
 
diff --git a/src/http/modules/ngx_http_upstream_keepalive_module.c b/src/http/modules/ngx_http_upstream_keepalive_module.c
new file mode 100644
index 000000000..945f78b15
--- /dev/null
+++ b/src/http/modules/ngx_http_upstream_keepalive_module.c
@@ -0,0 +1,569 @@
+
+/*
+ * Copyright (C) Maxim Dounin
+ */
+
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+#include <ngx_http.h>
+
+
+typedef struct {
+    ngx_uint_t                         max_cached;
+    ngx_uint_t                         single;       /* unsigned:1 */
+
+    ngx_queue_t                        cache;
+    ngx_queue_t                        free;
+
+    ngx_http_upstream_init_pt          original_init_upstream;
+    ngx_http_upstream_init_peer_pt     original_init_peer;
+
+} ngx_http_upstream_keepalive_srv_conf_t;
+
+
+typedef struct {
+    ngx_http_upstream_keepalive_srv_conf_t  *conf;
+
+    ngx_http_upstream_t               *upstream;
+
+    void                              *data;
+
+    ngx_event_get_peer_pt              original_get_peer;
+    ngx_event_free_peer_pt             original_free_peer;
+
+#if (NGX_HTTP_SSL)
+    ngx_event_set_peer_session_pt      original_set_session;
+    ngx_event_save_peer_session_pt     original_save_session;
+#endif
+
+    ngx_uint_t                         failed;       /* unsigned:1 */
+
+} ngx_http_upstream_keepalive_peer_data_t;
+
+
+typedef struct {
+    ngx_http_upstream_keepalive_srv_conf_t  *conf;
+
+    ngx_queue_t                        queue;
+    ngx_connection_t                  *connection;
+
+    socklen_t                          socklen;
+    u_char                             sockaddr[NGX_SOCKADDRLEN];
+
+} ngx_http_upstream_keepalive_cache_t;
+
+
+static ngx_int_t ngx_http_upstream_init_keepalive_peer(ngx_http_request_t *r,
+    ngx_http_upstream_srv_conf_t *us);
+static ngx_int_t ngx_http_upstream_get_keepalive_peer(ngx_peer_connection_t *pc,
+    void *data);
+static void ngx_http_upstream_free_keepalive_peer(ngx_peer_connection_t *pc,
+    void *data, ngx_uint_t state);
+
+static void ngx_http_upstream_keepalive_dummy_handler(ngx_event_t *ev);
+static void ngx_http_upstream_keepalive_close_handler(ngx_event_t *ev);
+static void ngx_http_upstream_keepalive_close(ngx_connection_t *c);
+
+
+#if (NGX_HTTP_SSL)
+static ngx_int_t ngx_http_upstream_keepalive_set_session(
+    ngx_peer_connection_t *pc, void *data);
+static void ngx_http_upstream_keepalive_save_session(ngx_peer_connection_t *pc,
+    void *data);
+#endif
+
+static void *ngx_http_upstream_keepalive_create_conf(ngx_conf_t *cf);
+static char *ngx_http_upstream_keepalive(ngx_conf_t *cf, ngx_command_t *cmd,
+    void *conf);
+
+
+static ngx_command_t  ngx_http_upstream_keepalive_commands[] = {
+
+    { ngx_string("keepalive"),
+      NGX_HTTP_UPS_CONF|NGX_CONF_TAKE12,
+      ngx_http_upstream_keepalive,
+      0,
+      0,
+      NULL },
+
+      ngx_null_command
+};
+
+
+static ngx_http_module_t  ngx_http_upstream_keepalive_module_ctx = {
+    NULL,                                  /* preconfiguration */
+    NULL,                                  /* postconfiguration */
+
+    NULL,                                  /* create main configuration */
+    NULL,                                  /* init main configuration */
+
+    ngx_http_upstream_keepalive_create_conf, /* create server configuration */
+    NULL,                                  /* merge server configuration */
+
+    NULL,                                  /* create location configuration */
+    NULL                                   /* merge location configuration */
+};
+
+
+ngx_module_t  ngx_http_upstream_keepalive_module = {
+    NGX_MODULE_V1,
+    &ngx_http_upstream_keepalive_module_ctx, /* module context */
+    ngx_http_upstream_keepalive_commands,    /* module directives */
+    NGX_HTTP_MODULE,                       /* module type */
+    NULL,                                  /* init master */
+    NULL,                                  /* init module */
+    NULL,                                  /* init process */
+    NULL,                                  /* init thread */
+    NULL,                                  /* exit thread */
+    NULL,                                  /* exit process */
+    NULL,                                  /* exit master */
+    NGX_MODULE_V1_PADDING
+};
+
+
+static ngx_int_t
+ngx_http_upstream_init_keepalive(ngx_conf_t *cf,
+    ngx_http_upstream_srv_conf_t *us)
+{
+    ngx_uint_t                               i;
+    ngx_http_upstream_keepalive_srv_conf_t  *kcf;
+    ngx_http_upstream_keepalive_cache_t     *cached;
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, cf->log, 0,
+                   "init keepalive");
+
+    kcf = ngx_http_conf_upstream_srv_conf(us,
+                                          ngx_http_upstream_keepalive_module);
+
+    if (kcf->original_init_upstream(cf, us) != NGX_OK) {
+        return NGX_ERROR;
+    }
+
+    kcf->original_init_peer = us->peer.init;
+
+    us->peer.init = ngx_http_upstream_init_keepalive_peer;
+
+    /* allocate cache items and add to free queue */
+
+    cached = ngx_pcalloc(cf->pool,
+                sizeof(ngx_http_upstream_keepalive_cache_t) * kcf->max_cached);
+    if (cached == NULL) {
+        return NGX_ERROR;
+    }
+
+    ngx_queue_init(&kcf->cache);
+    ngx_queue_init(&kcf->free);
+
+    for (i = 0; i < kcf->max_cached; i++) {
+        ngx_queue_insert_head(&kcf->free, &cached[i].queue);
+        cached[i].conf = kcf;
+    }
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t
+ngx_http_upstream_init_keepalive_peer(ngx_http_request_t *r,
+    ngx_http_upstream_srv_conf_t *us)
+{
+    ngx_http_upstream_keepalive_peer_data_t  *kp;
+    ngx_http_upstream_keepalive_srv_conf_t   *kcf;
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                   "init keepalive peer");
+
+    kcf = ngx_http_conf_upstream_srv_conf(us,
+                                          ngx_http_upstream_keepalive_module);
+
+    kp = ngx_palloc(r->pool, sizeof(ngx_http_upstream_keepalive_peer_data_t));
+    if (kp == NULL) {
+        return NGX_ERROR;
+    }
+
+    if (kcf->original_init_peer(r, us) != NGX_OK) {
+        return NGX_ERROR;
+    }
+
+    kp->conf = kcf;
+    kp->upstream = r->upstream;
+    kp->data = r->upstream->peer.data;
+    kp->original_get_peer = r->upstream->peer.get;
+    kp->original_free_peer = r->upstream->peer.free;
+
+    r->upstream->peer.data = kp;
+    r->upstream->peer.get = ngx_http_upstream_get_keepalive_peer;
+    r->upstream->peer.free = ngx_http_upstream_free_keepalive_peer;
+
+#if (NGX_HTTP_SSL)
+    kp->original_set_session = r->upstream->peer.set_session;
+    kp->original_save_session = r->upstream->peer.save_session;
+    r->upstream->peer.set_session = ngx_http_upstream_keepalive_set_session;
+    r->upstream->peer.save_session = ngx_http_upstream_keepalive_save_session;
+#endif
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t
+ngx_http_upstream_get_keepalive_peer(ngx_peer_connection_t *pc, void *data)
+{
+    ngx_http_upstream_keepalive_peer_data_t  *kp = data;
+    ngx_http_upstream_keepalive_cache_t      *item;
+
+    ngx_int_t          rc;
+    ngx_queue_t       *q, *cache;
+    ngx_connection_t  *c;
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, pc->log, 0,
+                   "get keepalive peer");
+
+    kp->failed = 0;
+
+    /* single pool of cached connections */
+
+    if (kp->conf->single && !ngx_queue_empty(&kp->conf->cache)) {
+
+        q = ngx_queue_head(&kp->conf->cache);
+
+        item = ngx_queue_data(q, ngx_http_upstream_keepalive_cache_t, queue);
+        c = item->connection;
+
+        ngx_queue_remove(q);
+        ngx_queue_insert_head(&kp->conf->free, q);
+
+        ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0,
+                       "get keepalive peer: using connection %p", c);
+
+        c->idle = 0;
+        c->log = pc->log;
+        c->read->log = pc->log;
+        c->write->log = pc->log;
+        c->pool->log = pc->log;
+
+        pc->connection = c;
+        pc->cached = 1;
+
+        return NGX_DONE;
+    }
+
+    rc = kp->original_get_peer(pc, kp->data);
+
+    if (kp->conf->single || rc != NGX_OK) {
+        return rc;
+    }
+
+    /* search cache for suitable connection */
+
+    cache = &kp->conf->cache;
+
+    for (q = ngx_queue_head(cache);
+         q != ngx_queue_sentinel(cache);
+         q = ngx_queue_next(q))
+    {
+        item = ngx_queue_data(q, ngx_http_upstream_keepalive_cache_t, queue);
+        c = item->connection;
+
+        if (ngx_memn2cmp((u_char *) &item->sockaddr, (u_char *) pc->sockaddr,
+                         item->socklen, pc->socklen)
+            == 0)
+        {
+            ngx_queue_remove(q);
+            ngx_queue_insert_head(&kp->conf->free, q);
+
+            ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0,
+                           "get keepalive peer: using connection %p", c);
+
+            c->idle = 0;
+            c->log = pc->log;
+            c->read->log = pc->log;
+            c->write->log = pc->log;
+            c->pool->log = pc->log;
+
+            pc->connection = c;
+            pc->cached = 1;
+
+            return NGX_DONE;
+        }
+    }
+
+    return NGX_OK;
+}
+
+
+static void
+ngx_http_upstream_free_keepalive_peer(ngx_peer_connection_t *pc, void *data,
+    ngx_uint_t state)
+{
+    ngx_http_upstream_keepalive_peer_data_t  *kp = data;
+    ngx_http_upstream_keepalive_cache_t      *item;
+
+    ngx_queue_t          *q;
+    ngx_connection_t     *c;
+    ngx_http_upstream_t  *u;
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, pc->log, 0,
+                   "free keepalive peer");
+
+    /* remember failed state - peer.free() may be called more than once */
+
+    if (state & NGX_PEER_FAILED) {
+        kp->failed = 1;
+    }
+
+    /* cache valid connections */
+
+    u = kp->upstream;
+    c = pc->connection;
+
+    if (kp->failed
+        || c == NULL
+        || c->read->eof
+        || c->read->error
+        || c->read->timedout
+        || c->write->error
+        || c->write->timedout)
+    {
+        goto invalid;
+    }
+
+    if (!u->keepalive) {
+        goto invalid;
+    }
+
+    if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
+        goto invalid;
+    }
+
+    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0,
+                   "free keepalive peer: saving connection %p", c);
+
+    if (ngx_queue_empty(&kp->conf->free)) {
+
+        q = ngx_queue_last(&kp->conf->cache);
+        ngx_queue_remove(q);
+
+        item = ngx_queue_data(q, ngx_http_upstream_keepalive_cache_t, queue);
+
+        ngx_http_upstream_keepalive_close(item->connection);
+
+    } else {
+        q = ngx_queue_head(&kp->conf->free);
+        ngx_queue_remove(q);
+
+        item = ngx_queue_data(q, ngx_http_upstream_keepalive_cache_t, queue);
+    }
+
+    item->connection = c;
+    ngx_queue_insert_head(&kp->conf->cache, q);
+
+    pc->connection = NULL;
+
+    if (c->read->timer_set) {
+        ngx_del_timer(c->read);
+    }
+    if (c->write->timer_set) {
+        ngx_del_timer(c->write);
+    }
+
+    c->write->handler = ngx_http_upstream_keepalive_dummy_handler;
+    c->read->handler = ngx_http_upstream_keepalive_close_handler;
+
+    c->data = item;
+    c->idle = 1;
+    c->log = ngx_cycle->log;
+    c->read->log = ngx_cycle->log;
+    c->write->log = ngx_cycle->log;
+    c->pool->log = ngx_cycle->log;
+
+    item->socklen = pc->socklen;
+    ngx_memcpy(&item->sockaddr, pc->sockaddr, pc->socklen);
+
+    if (c->read->ready) {
+        ngx_http_upstream_keepalive_close_handler(c->read);
+    }
+
+invalid:
+
+    kp->original_free_peer(pc, kp->data, state);
+}
+
+
+static void
+ngx_http_upstream_keepalive_dummy_handler(ngx_event_t *ev)
+{
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, ev->log, 0,
+                   "keepalive dummy handler");
+}
+
+
+static void
+ngx_http_upstream_keepalive_close_handler(ngx_event_t *ev)
+{
+    ngx_http_upstream_keepalive_srv_conf_t  *conf;
+    ngx_http_upstream_keepalive_cache_t     *item;
+
+    int                n;
+    char               buf[1];
+    ngx_connection_t  *c;
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, ev->log, 0,
+                   "keepalive close handler");
+
+    c = ev->data;
+
+    if (c->close) {
+        goto close;
+    }
+
+    n = recv(c->fd, buf, 1, MSG_PEEK);
+
+    if (n == -1 && ngx_socket_errno == NGX_EAGAIN) {
+        /* stale event */
+
+        if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
+            goto close;
+        }
+
+        return;
+    }
+
+close:
+
+    item = c->data;
+    conf = item->conf;
+
+    ngx_http_upstream_keepalive_close(c);
+
+    ngx_queue_remove(&item->queue);
+    ngx_queue_insert_head(&conf->free, &item->queue);
+}
+
+
+static void
+ngx_http_upstream_keepalive_close(ngx_connection_t *c)
+{
+
+#if (NGX_HTTP_SSL)
+
+    if (c->ssl) {
+        c->ssl->no_wait_shutdown = 1;
+        c->ssl->no_send_shutdown = 1;
+
+        if (ngx_ssl_shutdown(c) == NGX_AGAIN) {
+            c->ssl->handler = ngx_http_upstream_keepalive_close;
+            return;
+        }
+    }
+
+#endif
+
+    ngx_destroy_pool(c->pool);
+    ngx_close_connection(c);
+}
+
+
+#if (NGX_HTTP_SSL)
+
+static ngx_int_t
+ngx_http_upstream_keepalive_set_session(ngx_peer_connection_t *pc, void *data)
+{
+    ngx_http_upstream_keepalive_peer_data_t  *kp = data;
+
+    return kp->original_set_session(pc, kp->data);
+}
+
+
+static void
+ngx_http_upstream_keepalive_save_session(ngx_peer_connection_t *pc, void *data)
+{
+    ngx_http_upstream_keepalive_peer_data_t  *kp = data;
+
+    kp->original_save_session(pc, kp->data);
+    return;
+}
+
+#endif
+
+
+static void *
+ngx_http_upstream_keepalive_create_conf(ngx_conf_t *cf)
+{
+    ngx_http_upstream_keepalive_srv_conf_t  *conf;
+
+    conf = ngx_pcalloc(cf->pool,
+                       sizeof(ngx_http_upstream_keepalive_srv_conf_t));
+    if (conf == NULL) {
+        return NULL;
+    }
+
+    /*
+     * set by ngx_pcalloc():
+     *
+     *     conf->original_init_upstream = NULL;
+     *     conf->original_init_peer = NULL;
+     */
+
+    conf->max_cached = 1;
+
+    return conf;
+}
+
+
+static char *
+ngx_http_upstream_keepalive(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
+{
+    ngx_http_upstream_srv_conf_t            *uscf;
+    ngx_http_upstream_keepalive_srv_conf_t  *kcf;
+
+    ngx_int_t    n;
+    ngx_str_t   *value;
+    ngx_uint_t   i;
+
+    uscf = ngx_http_conf_get_module_srv_conf(cf, ngx_http_upstream_module);
+
+    kcf = ngx_http_conf_upstream_srv_conf(uscf,
+                                          ngx_http_upstream_keepalive_module);
+
+    kcf->original_init_upstream = uscf->peer.init_upstream
+                                  ? uscf->peer.init_upstream
+                                  : ngx_http_upstream_init_round_robin;
+
+    uscf->peer.init_upstream = ngx_http_upstream_init_keepalive;
+
+    /* read options */
+
+    value = cf->args->elts;
+
+    n = ngx_atoi(value[1].data, value[1].len);
+
+    if (n == NGX_ERROR || n == 0) {
+        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
+                           "invalid value \"%V\" in \"%V\" directive",
+                           &value[1], &cmd->name);
+        return NGX_CONF_ERROR;
+    }
+
+    kcf->max_cached = n;
+
+    for (i = 2; i < cf->args->nelts; i++) {
+
+        if (ngx_strcmp(value[i].data, "single") == 0) {
+            kcf->single = 1;
+            continue;
+        }
+
+        goto invalid;
+    }
+
+    return NGX_CONF_OK;
+
+invalid:
+
+    ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
+                       "invalid parameter \"%V\"", &value[i]);
+
+    return NGX_CONF_ERROR;
+}
diff --git a/src/http/modules/perl/nginx.pm b/src/http/modules/perl/nginx.pm
index 6dedc6d7d..429af0d1c 100644
--- a/src/http/modules/perl/nginx.pm
+++ b/src/http/modules/perl/nginx.pm
@@ -48,7 +48,7 @@ our @EXPORT = qw(
     HTTP_INSUFFICIENT_STORAGE
 );
 
-our $VERSION = '1.1.3';
+our $VERSION = '1.1.4';
 
 require XSLoader;
 XSLoader::load('nginx', $VERSION);
diff --git a/src/http/ngx_http.c b/src/http/ngx_http.c
index 5ca9fed3c..e8090453a 100644
--- a/src/http/ngx_http.c
+++ b/src/http/ngx_http.c
@@ -1226,7 +1226,7 @@ ngx_http_add_addresses(ngx_conf_t *cf, ngx_http_core_srv_conf_t *cscf,
 #endif
 
     /*
-     * we can not compare whole sockaddr struct's as kernel
+     * we cannot compare whole sockaddr struct's as kernel
      * may fill some fields in inherited sockaddr struct's
      */
 
diff --git a/src/http/ngx_http.h b/src/http/ngx_http.h
index e3619e148..3c1a9d275 100644
--- a/src/http/ngx_http.h
+++ b/src/http/ngx_http.h
@@ -52,6 +52,7 @@ struct ngx_http_log_ctx_s {
 
 
 typedef struct {
+    ngx_uint_t           http_version;
     ngx_uint_t           code;
     ngx_uint_t           count;
     u_char              *start;
diff --git a/src/http/ngx_http_core_module.c b/src/http/ngx_http_core_module.c
index ebe22ceaf..d51dc23d1 100644
--- a/src/http/ngx_http_core_module.c
+++ b/src/http/ngx_http_core_module.c
@@ -402,7 +402,7 @@ static ngx_command_t  ngx_http_core_commands[] = {
 
     { ngx_string("sendfile"),
       NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_HTTP_LIF_CONF
-                        |NGX_CONF_TAKE1,
+                        |NGX_CONF_FLAG,
       ngx_conf_set_flag_slot,
       NGX_HTTP_LOC_CONF_OFFSET,
       offsetof(ngx_http_core_loc_conf_t, sendfile),
@@ -639,7 +639,7 @@ static ngx_command_t  ngx_http_core_commands[] = {
       NULL },
 
     { ngx_string("chunked_transfer_encoding"),
-      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_FLAG,
       ngx_conf_set_flag_slot,
       NGX_HTTP_LOC_CONF_OFFSET,
       offsetof(ngx_http_core_loc_conf_t, chunked_transfer_encoding),
@@ -1259,7 +1259,7 @@ ngx_http_core_try_files_phase(ngx_http_request_t *r,
         tf++;
 
         ngx_log_debug3(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
-                       "try to use %s: \"%s\" \"%s\"",
+                       "trying to use %s: \"%s\" \"%s\"",
                        test_dir ? "dir" : "file", name, path.data);
 
         if (tf->lengths == NULL && tf->name.len == 0) {
@@ -1897,7 +1897,7 @@ ngx_http_map_uri_to_path(ngx_http_request_t *r, ngx_str_t *path,
 
     if (alias && !r->valid_location) {
         ngx_log_error(NGX_LOG_ALERT, r->connection->log, 0,
-                      "\"alias\" could not be used in location \"%V\" "
+                      "\"alias\" cannot be used in location \"%V\" "
                       "where URI was rewritten", &clcf->name);
         return NULL;
     }
@@ -2468,7 +2468,7 @@ ngx_http_internal_redirect(ngx_http_request_t *r,
     if (r->uri_changes == 0) {
         ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                       "rewrite or internal redirection cycle "
-                      "while internal redirect to \"%V\"", uri);
+                      "while internally redirecting to \"%V\"", uri);
 
         r->main->count++;
         ngx_http_finalize_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
@@ -2862,7 +2862,7 @@ ngx_http_core_location(ngx_conf_t *cf, ngx_command_t *cmd, void *dummy)
 
         if (pclcf->exact_match) {
             ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
-                               "location \"%V\" could not be inside "
+                               "location \"%V\" cannot be inside "
                                "the exact location \"%V\"",
                                &clcf->name, &pclcf->name);
             return NGX_CONF_ERROR;
@@ -2870,7 +2870,7 @@ ngx_http_core_location(ngx_conf_t *cf, ngx_command_t *cmd, void *dummy)
 
         if (pclcf->named) {
             ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
-                               "location \"%V\" could not be inside "
+                               "location \"%V\" cannot be inside "
                                "the named location \"%V\"",
                                &clcf->name, &pclcf->name);
             return NGX_CONF_ERROR;
@@ -2878,8 +2878,8 @@ ngx_http_core_location(ngx_conf_t *cf, ngx_command_t *cmd, void *dummy)
 
         if (clcf->named) {
             ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
-                               "named location \"%V\" must be "
-                               "on server level only",
+                               "named location \"%V\" can be "
+                               "on the server level only",
                                &clcf->name);
             return NGX_CONF_ERROR;
         }
@@ -2948,7 +2948,7 @@ ngx_http_core_regex_location(ngx_conf_t *cf, ngx_http_core_loc_conf_t *clcf,
 #else
 
     ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
-                       "the using of the regex \"%V\" requires PCRE library",
+                       "using regex \"%V\" requires PCRE library",
                        regex);
     return NGX_ERROR;
 
@@ -3024,9 +3024,9 @@ ngx_http_core_type(ngx_conf_t *cf, ngx_command_t *dummy, void *conf)
                 type[n].value = content_type;
 
                 ngx_conf_log_error(NGX_LOG_WARN, cf, 0,
-                                   "duplicate extention \"%V\", "
+                                   "duplicate extension \"%V\", "
                                    "content type: \"%V\", "
-                                   "old content type: \"%V\"",
+                                   "previous content type: \"%V\"",
                                    &value[i], content_type, old);
                 continue;
             }
@@ -3178,7 +3178,7 @@ ngx_http_core_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child)
     if (conf->large_client_header_buffers.size < conf->connection_pool_size) {
         ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                            "the \"large_client_header_buffers\" size must be "
-                           "equal to or bigger than \"connection_pool_size\"");
+                           "equal to or greater than \"connection_pool_size\"");
         return NGX_CONF_ERROR;
     }
 
@@ -3191,7 +3191,7 @@ ngx_http_core_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child)
                               prev->underscores_in_headers, 0);
 
     if (conf->server_names.nelts == 0) {
-        /* the array has 4 empty preallocated elements, so push can not fail */
+        /* the array has 4 empty preallocated elements, so push cannot fail */
         sn = ngx_array_push(&conf->server_names);
 #if (NGX_PCRE)
         sn->regex = NULL;
@@ -3779,7 +3779,7 @@ ngx_http_core_listen(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
             continue;
 #else
             ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
-                               "bind ipv6only is not supported "
+                               "ipv6only is not supported "
                                "on this platform");
             return NGX_CONF_ERROR;
 #endif
@@ -3798,7 +3798,7 @@ ngx_http_core_listen(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
         }
 
         ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
-                           "the invalid \"%V\" parameter", &value[n]);
+                           "invalid parameter \"%V\"", &value[n]);
         return NGX_CONF_ERROR;
     }
 
@@ -3836,7 +3836,7 @@ ngx_http_core_server_name(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
 
         if (ngx_strchr(value[i].data, '/')) {
             ngx_conf_log_error(NGX_LOG_WARN, cf, 0,
-                               "server name \"%V\" has strange symbols",
+                               "server name \"%V\" has suspicious symbols",
                                &value[i]);
         }
 
@@ -3907,7 +3907,7 @@ ngx_http_core_server_name(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
         }
 #else
         ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
-                           "the using of the regex \"%V\" "
+                           "using regex \"%V\" "
                            "requires PCRE library", &value[i]);
 
         return NGX_CONF_ERROR;
@@ -3939,7 +3939,7 @@ ngx_http_core_root(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
         } else {
             ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                                "\"%V\" directive is duplicate, "
-                               "\"%s\" directive is specified before",
+                               "\"%s\" directive was specified earlier",
                                &cmd->name, clcf->alias ? "alias" : "root");
         }
 
@@ -3948,8 +3948,8 @@ ngx_http_core_root(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
 
     if (clcf->named && alias) {
         ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
-                           "the \"alias\" directive may not be used "
-                           "inside named location");
+                           "the \"alias\" directive cannot be used "
+                           "inside the named location");
 
         return NGX_CONF_ERROR;
     }
@@ -3960,7 +3960,7 @@ ngx_http_core_root(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
         || ngx_strstr(value[1].data, "${document_root}"))
     {
         ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
-                           "the $document_root variable may not be used "
+                           "the $document_root variable cannot be used "
                            "in the \"%V\" directive",
                            &cmd->name);
 
@@ -3971,7 +3971,7 @@ ngx_http_core_root(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
         || ngx_strstr(value[1].data, "${realpath_root}"))
     {
         ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
-                           "the $realpath_root variable may not be used "
+                           "the $realpath_root variable cannot be used "
                            "in the \"%V\" directive",
                            &cmd->name);
 
@@ -4430,7 +4430,7 @@ ngx_http_core_open_file_cache(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
 
     if (max == 0) {
         ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
-                           "\"open_file_cache\" must have \"max\" parameter");
+                           "\"open_file_cache\" must have the \"max\" parameter");
         return NGX_CONF_ERROR;
     }
 
diff --git a/src/http/ngx_http_parse.c b/src/http/ngx_http_parse.c
index 949006b47..a7a4c6ee6 100644
--- a/src/http/ngx_http_parse.c
+++ b/src/http/ngx_http_parse.c
@@ -1403,6 +1403,7 @@ ngx_http_parse_status_line(ngx_http_request_t *r, ngx_buf_t *b,
                 return NGX_ERROR;
             }
 
+            r->http_major = ch - '0';
             state = sw_major_digit;
             break;
 
@@ -1417,6 +1418,7 @@ ngx_http_parse_status_line(ngx_http_request_t *r, ngx_buf_t *b,
                 return NGX_ERROR;
             }
 
+            r->http_major = r->http_major * 10 + ch - '0';
             break;
 
         /* the first digit of minor HTTP version */
@@ -1425,6 +1427,7 @@ ngx_http_parse_status_line(ngx_http_request_t *r, ngx_buf_t *b,
                 return NGX_ERROR;
             }
 
+            r->http_minor = ch - '0';
             state = sw_minor_digit;
             break;
 
@@ -1439,6 +1442,7 @@ ngx_http_parse_status_line(ngx_http_request_t *r, ngx_buf_t *b,
                 return NGX_ERROR;
             }
 
+            r->http_minor = r->http_minor * 10 + ch - '0';
             break;
 
         /* HTTP status code */
@@ -1516,6 +1520,7 @@ done:
         status->end = p;
     }
 
+    status->http_version = r->http_major * 1000 + r->http_minor;
     r->state = sw_start;
 
     return NGX_OK;
diff --git a/src/http/ngx_http_upstream.c b/src/http/ngx_http_upstream.c
index 29432dc14..ef16a662c 100644
--- a/src/http/ngx_http_upstream.c
+++ b/src/http/ngx_http_upstream.c
@@ -72,6 +72,8 @@ static void ngx_http_upstream_finalize_request(ngx_http_request_t *r,
 
 static ngx_int_t ngx_http_upstream_process_header_line(ngx_http_request_t *r,
     ngx_table_elt_t *h, ngx_uint_t offset);
+static ngx_int_t ngx_http_upstream_process_content_length(ngx_http_request_t *r,
+    ngx_table_elt_t *h, ngx_uint_t offset);
 static ngx_int_t ngx_http_upstream_process_set_cookie(ngx_http_request_t *r,
     ngx_table_elt_t *h, ngx_uint_t offset);
 static ngx_int_t
@@ -89,6 +91,11 @@ static ngx_int_t ngx_http_upstream_process_buffering(ngx_http_request_t *r,
     ngx_table_elt_t *h, ngx_uint_t offset);
 static ngx_int_t ngx_http_upstream_process_charset(ngx_http_request_t *r,
     ngx_table_elt_t *h, ngx_uint_t offset);
+static ngx_int_t ngx_http_upstream_process_connection(ngx_http_request_t *r,
+    ngx_table_elt_t *h, ngx_uint_t offset);
+static ngx_int_t
+    ngx_http_upstream_process_transfer_encoding(ngx_http_request_t *r,
+    ngx_table_elt_t *h, ngx_uint_t offset);
 static ngx_int_t ngx_http_upstream_copy_header_line(ngx_http_request_t *r,
     ngx_table_elt_t *h, ngx_uint_t offset);
 static ngx_int_t
@@ -96,8 +103,6 @@ static ngx_int_t
     ngx_table_elt_t *h, ngx_uint_t offset);
 static ngx_int_t ngx_http_upstream_copy_content_type(ngx_http_request_t *r,
     ngx_table_elt_t *h, ngx_uint_t offset);
-static ngx_int_t ngx_http_upstream_copy_content_length(ngx_http_request_t *r,
-    ngx_table_elt_t *h, ngx_uint_t offset);
 static ngx_int_t ngx_http_upstream_copy_last_modified(ngx_http_request_t *r,
     ngx_table_elt_t *h, ngx_uint_t offset);
 static ngx_int_t ngx_http_upstream_rewrite_location(ngx_http_request_t *r,
@@ -149,9 +154,9 @@ ngx_http_upstream_header_t  ngx_http_upstream_headers_in[] = {
                  ngx_http_upstream_copy_content_type, 0, 1 },
 
     { ngx_string("Content-Length"),
-                 ngx_http_upstream_process_header_line,
+                 ngx_http_upstream_process_content_length,
                  offsetof(ngx_http_upstream_headers_in_t, content_length),
-                 ngx_http_upstream_copy_content_length, 0, 0 },
+                 ngx_http_upstream_ignore_header_line, 0, 0 },
 
     { ngx_string("Date"),
                  ngx_http_upstream_process_header_line,
@@ -215,7 +220,7 @@ ngx_http_upstream_header_t  ngx_http_upstream_headers_in[] = {
                  offsetof(ngx_http_headers_out_t, accept_ranges), 1 },
 
     { ngx_string("Connection"),
-                 ngx_http_upstream_ignore_header_line, 0,
+                 ngx_http_upstream_process_connection, 0,
                  ngx_http_upstream_ignore_header_line, 0, 0 },
 
     { ngx_string("Keep-Alive"),
@@ -247,6 +252,10 @@ ngx_http_upstream_header_t  ngx_http_upstream_headers_in[] = {
                  ngx_http_upstream_process_charset, 0,
                  ngx_http_upstream_copy_header_line, 0, 0 },
 
+    { ngx_string("Transfer-Encoding"),
+                 ngx_http_upstream_process_transfer_encoding, 0,
+                 ngx_http_upstream_ignore_header_line, 0, 0 },
+
 #if (NGX_HTTP_GZIP)
     { ngx_string("Content-Encoding"),
                  ngx_http_upstream_process_header_line,
@@ -396,6 +405,8 @@ ngx_http_upstream_create(ngx_http_request_t *r)
     r->cache = NULL;
 #endif
 
+    u->headers_in.content_length_n = -1;
+
     return NGX_OK;
 }
 
@@ -800,6 +811,7 @@ ngx_http_upstream_cache_send(ngx_http_request_t *r, ngx_http_upstream_t *u)
     u->buffer.pos += c->header_start;
 
     ngx_memzero(&u->headers_in, sizeof(ngx_http_upstream_headers_in_t));
+    u->headers_in.content_length_n = -1;
 
     if (ngx_list_init(&u->headers_in.headers, r->pool, 8,
                       sizeof(ngx_table_elt_t))
@@ -1136,8 +1148,20 @@ ngx_http_upstream_connect(ngx_http_request_t *r, ngx_http_upstream_t *u)
     c->sendfile &= r->connection->sendfile;
     u->output.sendfile = c->sendfile;
 
-    c->pool = r->pool;
+    if (c->pool == NULL) {
+
+        /* we need separate pool here to be able to cache SSL connections */
+
+        c->pool = ngx_create_pool(128, r->connection->log);
+        if (c->pool == NULL) {
+            ngx_http_upstream_finalize_request(r, u,
+                                               NGX_HTTP_INTERNAL_SERVER_ERROR);
+            return;
+        }
+    }
+
     c->log = r->connection->log;
+    c->pool->log = c->log;
     c->read->log = c->log;
     c->write->log = c->log;
 
@@ -1282,7 +1306,10 @@ ngx_http_upstream_reinit(ngx_http_request_t *r, ngx_http_upstream_t *u)
         return NGX_ERROR;
     }
 
+    u->keepalive = 0;
+
     ngx_memzero(&u->headers_in, sizeof(ngx_http_upstream_headers_in_t));
+    u->headers_in.content_length_n = -1;
 
     if (ngx_list_init(&u->headers_in.headers, r->pool, 8,
                       sizeof(ngx_table_elt_t))
@@ -1924,14 +1951,9 @@ ngx_http_upstream_process_headers(ngx_http_request_t *r, ngx_http_upstream_t *u)
     r->headers_out.status = u->headers_in.status_n;
     r->headers_out.status_line = u->headers_in.status_line;
 
-    u->headers_in.content_length_n = r->headers_out.content_length_n;
-
-    if (r->headers_out.content_length_n != -1) {
-        u->length = (size_t) r->headers_out.content_length_n;
+    r->headers_out.content_length_n = u->headers_in.content_length_n;
 
-    } else {
-        u->length = NGX_MAX_SIZE_T_VALUE;
-    }
+    u->length = u->headers_in.content_length_n;
 
     return NGX_OK;
 }
@@ -1995,6 +2017,11 @@ ngx_http_upstream_process_body_in_memory(ngx_http_request_t *r,
         }
     }
 
+    if (u->length == 0) {
+        ngx_http_upstream_finalize_request(r, u, 0);
+        return;
+    }
+
     if (ngx_handle_read_event(rev, 0) != NGX_OK) {
         ngx_http_upstream_finalize_request(r, u, NGX_ERROR);
         return;
@@ -2115,7 +2142,7 @@ ngx_http_upstream_send_response(ngx_http_request_t *r, ngx_http_upstream_t *u)
                 return;
             }
 
-            if (u->peer.connection->read->ready) {
+            if (u->peer.connection->read->ready || u->length == 0) {
                 ngx_http_upstream_process_non_buffered_upstream(r, u);
             }
         }
@@ -2293,6 +2320,15 @@ ngx_http_upstream_send_response(ngx_http_request_t *r, ngx_http_upstream_t *u)
     p->send_timeout = clcf->send_timeout;
     p->send_lowat = clcf->send_lowat;
 
+    p->length = -1;
+
+    if (u->input_filter_init
+        && u->input_filter_init(p->input_ctx) != NGX_OK)
+    {
+        ngx_http_upstream_finalize_request(r, u, 0);
+        return;
+    }
+
     u->read_event_handler = ngx_http_upstream_process_upstream;
     r->write_event_handler = ngx_http_upstream_process_downstream;
 
@@ -2382,7 +2418,7 @@ ngx_http_upstream_process_non_buffered_request(ngx_http_request_t *r,
                     return;
                 }
 
-                ngx_chain_update_chains(&u->free_bufs, &u->busy_bufs,
+                ngx_chain_update_chains(r->pool, &u->free_bufs, &u->busy_bufs,
                                         &u->out_bufs, u->output.tag);
             }
 
@@ -2403,10 +2439,6 @@ ngx_http_upstream_process_non_buffered_request(ngx_http_request_t *r,
 
         size = b->end - b->last;
 
-        if (size > u->length) {
-            size = u->length;
-        }
-
         if (size && upstream->read->ready) {
 
             n = upstream->recv(upstream, b->last, size);
@@ -2503,7 +2535,7 @@ ngx_http_upstream_non_buffered_filter(void *data, ssize_t bytes)
     cl->buf->last = b->last;
     cl->buf->tag = u->output.tag;
 
-    if (u->length == NGX_MAX_SIZE_T_VALUE) {
+    if (u->length == -1) {
         return NGX_OK;
     }
 
@@ -2812,6 +2844,10 @@ ngx_http_upstream_next(ngx_http_request_t *r, ngx_http_upstream_t *u,
     if (u->peer.cached && ft_type == NGX_HTTP_UPSTREAM_FT_ERROR) {
         status = 0;
 
+        /* TODO: inform balancer instead */
+
+        u->peer.tries++;
+
     } else {
         switch(ft_type) {
 
@@ -2886,6 +2922,10 @@ ngx_http_upstream_next(ngx_http_request_t *r, ngx_http_upstream_t *u,
         }
 #endif
 
+        if (u->peer.connection->pool) {
+            ngx_destroy_pool(u->peer.connection->pool);
+        }
+
         ngx_close_connection(u->peer.connection);
     }
 
@@ -2980,6 +3020,10 @@ ngx_http_upstream_finalize_request(ngx_http_request_t *r,
                        "close http upstream connection: %d",
                        u->peer.connection->fd);
 
+        if (u->peer.connection->pool) {
+            ngx_destroy_pool(u->peer.connection->pool);
+        }
+
         ngx_close_connection(u->peer.connection);
     }
 
@@ -3060,6 +3104,21 @@ ngx_http_upstream_ignore_header_line(ngx_http_request_t *r, ngx_table_elt_t *h,
 
 
 static ngx_int_t
+ngx_http_upstream_process_content_length(ngx_http_request_t *r,
+    ngx_table_elt_t *h, ngx_uint_t offset)
+{
+    ngx_http_upstream_t  *u;
+
+    u = r->upstream;
+
+    u->headers_in.content_length = h;
+    u->headers_in.content_length_n = ngx_atoof(h->value.data, h->value.len);
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t
 ngx_http_upstream_process_set_cookie(ngx_http_request_t *r, ngx_table_elt_t *h,
     ngx_uint_t offset)
 {
@@ -3321,6 +3380,40 @@ ngx_http_upstream_process_charset(ngx_http_request_t *r, ngx_table_elt_t *h,
 
 
 static ngx_int_t
+ngx_http_upstream_process_connection(ngx_http_request_t *r, ngx_table_elt_t *h,
+    ngx_uint_t offset)
+{
+    r->upstream->headers_in.connection = h;
+
+    if (ngx_strlcasestrn(h->value.data, h->value.data + h->value.len,
+                         (u_char *) "close", 5 - 1)
+        != NULL)
+    {
+        r->upstream->headers_in.connection_close = 1;
+    }
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t
+ngx_http_upstream_process_transfer_encoding(ngx_http_request_t *r,
+    ngx_table_elt_t *h, ngx_uint_t offset)
+{
+    r->upstream->headers_in.transfer_encoding = h;
+
+    if (ngx_strlcasestrn(h->value.data, h->value.data + h->value.len,
+                         (u_char *) "chunked", 7 - 1)
+        != NULL)
+    {
+        r->upstream->headers_in.chunked = 1;
+    }
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t
 ngx_http_upstream_copy_header_line(ngx_http_request_t *r, ngx_table_elt_t *h,
     ngx_uint_t offset)
 {
@@ -3428,26 +3521,6 @@ ngx_http_upstream_copy_content_type(ngx_http_request_t *r, ngx_table_elt_t *h,
 
 
 static ngx_int_t
-ngx_http_upstream_copy_content_length(ngx_http_request_t *r, ngx_table_elt_t *h,
-    ngx_uint_t offset)
-{
-    ngx_table_elt_t  *ho;
-
-    ho = ngx_list_push(&r->headers_out.headers);
-    if (ho == NULL) {
-        return NGX_ERROR;
-    }
-
-    *ho = *h;
-
-    r->headers_out.content_length = ho;
-    r->headers_out.content_length_n = ngx_atoof(h->value.data, h->value.len);
-
-    return NGX_OK;
-}
-
-
-static ngx_int_t
 ngx_http_upstream_copy_last_modified(ngx_http_request_t *r, ngx_table_elt_t *h,
     ngx_uint_t offset)
 {
diff --git a/src/http/ngx_http_upstream.h b/src/http/ngx_http_upstream.h
index fa848c0d3..bcdd64b16 100644
--- a/src/http/ngx_http_upstream.h
+++ b/src/http/ngx_http_upstream.h
@@ -217,6 +217,7 @@ typedef struct {
     ngx_table_elt_t                 *location;
     ngx_table_elt_t                 *accept_ranges;
     ngx_table_elt_t                 *www_authenticate;
+    ngx_table_elt_t                 *transfer_encoding;
 
 #if (NGX_HTTP_GZIP)
     ngx_table_elt_t                 *content_encoding;
@@ -225,6 +226,9 @@ typedef struct {
     off_t                            content_length_n;
 
     ngx_array_t                      cache_control;
+
+    unsigned                         connection_close:1;
+    unsigned                         chunked:1;
 } ngx_http_upstream_headers_in_t;
 
 
@@ -267,7 +271,7 @@ struct ngx_http_upstream_s {
     ngx_http_upstream_resolved_t    *resolved;
 
     ngx_buf_t                        buffer;
-    size_t                           length;
+    off_t                            length;
 
     ngx_chain_t                     *out_bufs;
     ngx_chain_t                     *busy_bufs;
@@ -308,6 +312,7 @@ struct ngx_http_upstream_s {
 #endif
 
     unsigned                         buffering:1;
+    unsigned                         keepalive:1;
 
     unsigned                         request_sent:1;
     unsigned                         header_sent:1;
diff --git a/src/os/unix/ngx_errno.c b/src/os/unix/ngx_errno.c
index 02994b808..faae47829 100644
--- a/src/os/unix/ngx_errno.c
+++ b/src/os/unix/ngx_errno.c
@@ -12,7 +12,7 @@
  * The strerror() messages are copied because:
  *
  * 1) strerror() and strerror_r() functions are not Async-Signal-Safe,
- *    therefore, they can not be used in signal handlers;
+ *    therefore, they cannot be used in signal handlers;
  *
  * 2) a direct sys_errlist[] array may be used instead of these functions,
  *    but Linux linker warns about its usage:
diff --git a/src/os/unix/ngx_file_aio_read.c b/src/os/unix/ngx_file_aio_read.c
index 557f9de6a..49662365f 100644
--- a/src/os/unix/ngx_file_aio_read.c
+++ b/src/os/unix/ngx_file_aio_read.c
@@ -23,7 +23,7 @@
  *    kqueue EVFILT_AIO filter is level triggered only: an event repeats
  *    until aio_return() will be called;
  *
- *    aio_cancel() can not cancel file AIO: it returns AIO_NOTCANCELED always.
+ *    aio_cancel() cannot cancel file AIO: it returns AIO_NOTCANCELED always.
  */
 
 
diff --git a/src/os/unix/ngx_freebsd_sendfile_chain.c b/src/os/unix/ngx_freebsd_sendfile_chain.c
index 70cdb7495..039243e96 100644
--- a/src/os/unix/ngx_freebsd_sendfile_chain.c
+++ b/src/os/unix/ngx_freebsd_sendfile_chain.c
@@ -11,7 +11,7 @@
 
 /*
  * Although FreeBSD sendfile() allows to pass a header and a trailer,
- * it can not send a header with a part of the file in one packet until
+ * it cannot send a header with a part of the file in one packet until
  * FreeBSD 5.3.  Besides, over the fast ethernet connection sendfile()
  * may send the partially filled packets, i.e. the 8 file pages may be sent
  * as the 11 full 1460-bytes packets, then one incomplete 324-bytes packet,
diff --git a/src/os/unix/ngx_linux_aio_read.c b/src/os/unix/ngx_linux_aio_read.c
index b9d1d01cd..d31c4a064 100644
--- a/src/os/unix/ngx_linux_aio_read.c
+++ b/src/os/unix/ngx_linux_aio_read.c
@@ -16,7 +16,7 @@ extern aio_context_t  ngx_aio_ctx;
 static void ngx_file_aio_event_handler(ngx_event_t *ev);
 
 
-static long
+static int
 io_submit(aio_context_t ctx, long n, struct iocb **paiocb)
 {
     return syscall(SYS_io_submit, ctx, n, paiocb);
@@ -27,7 +27,7 @@ ssize_t
 ngx_file_aio_read(ngx_file_t *file, u_char *buf, size_t size, off_t offset,
     ngx_pool_t *pool)
 {
-    long              n;
+    ngx_err_t         err;
     struct iocb      *piocb[1];
     ngx_event_t      *ev;
     ngx_event_aio_t  *aio;
@@ -96,9 +96,7 @@ ngx_file_aio_read(ngx_file_t *file, u_char *buf, size_t size, off_t offset,
 
     piocb[0] = &aio->aiocb;
 
-    n = io_submit(ngx_aio_ctx, 1, piocb);
-
-    if (n == 1) {
+    if (io_submit(ngx_aio_ctx, 1, piocb) == 1) {
         ev->active = 1;
         ev->ready = 0;
         ev->complete = 0;
@@ -106,16 +104,16 @@ ngx_file_aio_read(ngx_file_t *file, u_char *buf, size_t size, off_t offset,
         return NGX_AGAIN;
     }
 
-    n = -n;
+    err = ngx_errno;
 
-    if (n == NGX_EAGAIN) {
+    if (err == NGX_EAGAIN) {
         return ngx_read_file(file, buf, size, offset);
     }
 
-    ngx_log_error(NGX_LOG_CRIT, file->log, n,
+    ngx_log_error(NGX_LOG_CRIT, file->log, err,
                   "io_submit(\"%V\") failed", &file->name);
 
-    if (n == NGX_ENOSYS) {
+    if (err == NGX_ENOSYS) {
         ngx_file_aio = 0;
         return ngx_read_file(file, buf, size, offset);
     }
diff --git a/src/os/unix/ngx_process.c b/src/os/unix/ngx_process.c
index ad2fc19de..08069c4b6 100644
--- a/src/os/unix/ngx_process.c
+++ b/src/os/unix/ngx_process.c
@@ -541,7 +541,7 @@ ngx_process_get_status(void)
         if (WEXITSTATUS(status) == 2 && ngx_processes[i].respawn) {
             ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, 0,
                           "%s %P exited with fatal code %d "
-                          "and can not be respawn",
+                          "and cannot be respawned",
                           process, pid, WEXITSTATUS(status));
             ngx_processes[i].respawn = 0;
         }
diff --git a/src/os/unix/ngx_process_cycle.c b/src/os/unix/ngx_process_cycle.c
index 3ff0f75c6..863176fac 100644
--- a/src/os/unix/ngx_process_cycle.c
+++ b/src/os/unix/ngx_process_cycle.c
@@ -620,7 +620,8 @@ ngx_reap_children(ngx_cycle_t *cycle)
                     == NGX_INVALID_PID)
                 {
                     ngx_log_error(NGX_LOG_ALERT, cycle->log, 0,
-                                  "can not respawn %s", ngx_processes[i].name);
+                                  "could not respawn %s",
+                                  ngx_processes[i].name);
                     continue;
                 }