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author | Rob Harrop <rob@rabbitmq.com> | 2010-11-05 00:43:08 +0000 |
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committer | Rob Harrop <rob@rabbitmq.com> | 2010-11-05 00:43:08 +0000 |
commit | 5d600413dee1ad71d4bb6efc1597e1c3e334fb9b (patch) | |
tree | 0df3a9bcb474f7a64c2d09dee3e5f201a7602ea0 | |
parent | 6fde9cbafc73040b33cb750a8e429209df1ae473 (diff) | |
download | rabbitmq-server-5d600413dee1ad71d4bb6efc1597e1c3e334fb9b.tar.gz |
a bit more clarification on the comments
-rw-r--r-- | src/rabbit_variable_queue.erl | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/src/rabbit_variable_queue.erl b/src/rabbit_variable_queue.erl index 8b36767c..11e55353 100644 --- a/src/rabbit_variable_queue.erl +++ b/src/rabbit_variable_queue.erl @@ -89,12 +89,14 @@ %% %% The duration indicated to us by the memory_monitor is used to %% calculate, given our current ingress and egress rates, how many -%% messages we should hold in RAM. When we need to push alphas to -%% betas or betas to gammas, we favour writing out messages that are -%% further from the head of the queue. This minimises writes to disk, -%% as the messages closer to the tail of the queue stay in the queue -%% for longer, thus do not need to be replaced as quickly by sending -%% other messages to disk. +%% messages we should hold in RAM. We track the ingress and egress +%% rates for both messages and pending acks and rates for both are +%% included when calculating the number of messages to hold in +%% RAM. When we need to push alphas to betas or betas to gammas, we +%% favour writing out messages that are further from the head of the +%% queue. This minimises writes to disk, as the messages closer to the +%% tail of the queue stay in the queue for longer, thus do not need to +%% be replaced as quickly by sending other messages to disk. %% %% Whilst messages are pushed to disk and forgotten from RAM as soon %% as requested by a new setting of the queue RAM duration, the |