diff options
| -rw-r--r-- | src/rabbit_variable_queue.erl | 15 |
1 files changed, 8 insertions, 7 deletions
diff --git a/src/rabbit_variable_queue.erl b/src/rabbit_variable_queue.erl index 11e5535362..1b86320b64 100644 --- a/src/rabbit_variable_queue.erl +++ b/src/rabbit_variable_queue.erl @@ -91,7 +91,7 @@ %% calculate, given our current ingress and egress rates, how many %% 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 +%% considered 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 @@ -179,12 +179,13 @@ %% written to disk, acks are stored in message form to avoid the %% overhead of writing to disk. %% -%% During memory reduction, messages stored as transient ack records -%% are pushed out to disk before messages in the queue. More -%% precisely, messages from the queue will not be pushed out to disk -%% while the number of messages stored for acks is greater than -%% zero. Messages for acks are written to disk in batches of at most -%% ?IO_BATCH_SIZE. +%% During memory reduction, acks stored in message form are converted +%% to tuple form, and the corresponding messages are pushed out to +%% disk. Message form acks are always pushed to disk before messages +%% stored in the queue. More precisely, messages from the queue will +%% not be pushed out to disk while the number of messages form acks is +%% greater than zero. Message form acks are converted to tuple form in +%% batches of at most ?IO_BATCH_SIZE. %% %% Notes on Clean Shutdown %% (This documents behaviour in variable_queue, queue_index and |