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|
#!/bin/sh
# This must run as root as CTDB tool commands need to access CTDB socket
[ $(id -u) -eq 0 ] || exec sudo "$0" "$@"
# this script needs to be installed so that statd points to it with the -H
# command line argument. The easiest way to do that is to put something like this in
# /etc/sysconfig/nfs:
# STATD_HOSTNAME="myhostname -H /etc/ctdb/statd-callout"
[ -n "$CTDB_BASE" ] || \
export CTDB_BASE=$(cd -P $(dirname "$0") ; echo "$PWD")
. $CTDB_BASE/functions
# Overwrite this so we get some logging
die ()
{
script_log "statd-callout" "$@"
exit 1
}
loadconfig ctdb
loadconfig nfs
[ -n "$NFS_HOSTNAME" ] || \
die "NFS_HOSTNAME is not configured. statd-callout failed"
# A handy newline
nl="
"
ctdb_setup_service_state_dir "statd-callout"
cd "$service_state_dir" || \
die "Failed to change directory to \"${service_state_dir}\""
case "$1" in
# Keep a single file to keep track of the last "add-client" or
# "del-client'. These get pushed to ctdb.tdb during "update",
# which will generally be run once each "monitor" cycle. In this
# way we avoid scalability problems with flood of persistent
# transactions after a "notify" when all the clients re-take their
# locks.
add-client)
# statd does not tell us to which IP the client connected so
# we must add it to all the IPs that we serve
cip="$2"
ctdb_get_pnn
date=$(date '+%s')
ctdb ip -X |
tail -n +2 |
while IFS="|" read x sip node x ; do
[ "$node" = "$pnn" ] || continue # not us
key="statd-state@${sip}@${cip}"
echo "\"${key}\" \"${date}\"" >"$key"
done
;;
del-client)
# statd does not tell us from which IP the client disconnected
# so we must add it to all the IPs that we serve
cip="$2"
ctdb_get_pnn
ctdb ip -X |
tail -n +2 |
while IFS="|" read x sip node x ; do
[ "$node" = "$pnn" ] || continue # not us
key="statd-state@${sip}@${cip}"
echo "\"${key}\" \"\"" >"$key"
done
;;
update)
files=$(echo statd-state@*)
if [ "$files" = "statd-state@*" ] ; then
# No files!
exit 0
fi
# Filter out lines for any IP addresses that are not currently
# hosted public IP addresses.
ctdb_get_pnn
ctdb_ips=$(ctdb ip | tail -n +2)
sed_expr=$(echo "$ctdb_ips" |
awk -v pnn=$pnn 'pnn == $2 { \
ip = $1; gsub(/\./, "\\.", ip); \
printf "/statd-state@%s@/p\n", ip }')
if cat $files | sed -n "$sed_expr" | ctdb ptrans "ctdb.tdb" ; then
rm $files
fi
;;
notify)
# we must restart the lockmanager (on all nodes) so that we get
# a clusterwide grace period (so other clients don't take out
# conflicting locks through other nodes before all locks have been
# reclaimed)
# we need these settings to make sure that no tcp connections survive
# across a very fast failover/failback
#echo 10 > /proc/sys/net/ipv4/tcp_fin_timeout
#echo 0 > /proc/sys/net/ipv4/tcp_max_tw_buckets
#echo 0 > /proc/sys/net/ipv4/tcp_max_orphans
# Delete the notification list for statd, we don't want it to
# ping any clients
rm -f /var/lib/nfs/statd/sm/*
rm -f /var/lib/nfs/statd/sm.bak/*
# we must keep a monotonically increasing state variable for the entire
# cluster so state always increases when ip addresses fail from one
# node to another
# We use epoch and hope the nodes are close enough in clock.
# Even numbers mean service is shut down, odd numbers mean
# service is started.
state_even=$(( $(date '+%s') / 2 * 2))
# We must also let some time pass between stopping and
# restarting the lock manager. Otherwise there is a window
# where the lock manager will respond "strangely" immediately
# after restarting it, which causes clients to fail to reclaim
# their locks.
"$CTDB_NFS_CALLOUT" "stop" "nlockmgr" >/dev/null 2>&1
sleep 2
"$CTDB_NFS_CALLOUT" "start" "nlockmgr" >/dev/null 2>&1
# we now need to send out additional statd notifications to ensure
# that clients understand that the lockmanager has restarted.
# we have three cases:
# 1, clients that ignore the ip address the stat notification came from
# and ONLY care about the 'name' in the notify packet.
# these clients ONLY work with lock failover IFF that name
# can be resolved into an ipaddress that matches the one used
# to mount the share. (==linux clients)
# This is handled when starting lockmanager above, but those
# packets are sent from the "wrong" ip address, something linux
# clients are ok with, buth other clients will barf at.
# 2, Some clients only accept statd packets IFF they come from the
# 'correct' ip address.
# 2a,Send out the notification using the 'correct' ip address and also
# specify the 'correct' hostname in the statd packet.
# Some clients require both the correct source address and also the
# correct name. (these clients also ONLY work if the ip addresses
# used to map the share can be resolved into the name returned in
# the notify packet.)
# 2b,Other clients require that the source ip address of the notify
# packet matches the ip address used to take out the lock.
# I.e. that the correct source address is used.
# These clients also require that the statd notify packet contains
# the name as the ip address used when the lock was taken out.
#
# Both 2a and 2b are commonly used in lockmanagers since they maximize
# probability that the client will accept the statd notify packet and
# not just ignore it.
# For all IPs we serve, collect info and push to the config database
ctdb_get_pnn
# Construct a sed expression to take catdb output and produce pairs of:
# server-IP client-IP
# but only for the server-IPs that are hosted on this node.
ctdb_all_ips=$(ctdb ip all | tail -n +2)
sed_expr=$(echo "$ctdb_all_ips" |
awk -v pnn=$pnn 'pnn == $2 { \
ip = $1; gsub(/\./, "\\.", ip); \
printf "s/^key.*=.*statd-state@\\(%s\\)@\\([^\"]*\\).*/\\1 \\2/p\n", ip }')
statd_state=$(ctdb catdb ctdb.tdb | sed -n "$sed_expr" | sort)
[ -n "$statd_state" ] || exit 0
prev=""
echo "$statd_state" | {
# This all needs to be in the same command group at the
# end of the pipe so it doesn't get lost when the loop
# completes.
items=""
while read sip cip ; do
# Collect item to delete from the DB
key="statd-state@${sip}@${cip}"
item="\"${key}\" \"\""
items="${items}${items:+${nl}}${item}"
# NOTE: Consider optimising smnotify to read all the
# data from stdin and then run it in the background.
# Reset stateval for each serverip
[ "$sip" = "$prev" ] || stateval="$state_even"
# Send notifies for server shutdown
smnotify --client=$cip --ip=$sip --server=$sip --stateval=$stateval
smnotify --client=$cip --ip=$sip --server=$NFS_HOSTNAME --stateval=$stateval
# Send notifies for server startup
stateval=$(($stateval + 1))
smnotify --client=$cip --ip=$sip --server=$sip --stateval=$stateval
smnotify --client=$cip --ip=$sip --server=$NFS_HOSTNAME --stateval=$stateval
done
echo "$items" | ctdb ptrans "ctdb.tdb"
}
# Remove any stale touch files (i.e. for IPs not currently
# hosted on this node and created since the last "update").
# There's nothing else we can do with them at this stage.
echo "$ctdb_all_ips" |
awk -v pnn=$pnn 'pnn != $2 { print $1 }' |
while read sip ; do
rm -f "statd-state@${sip}@"*
done
;;
esac
|
