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https://issues.apache.org/jira/browse/AMQ-4666?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14272816#comment-14272816
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Tim Bain commented on AMQ-4666:
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I overlooked your statement that you're using persistent messages; sorry about
that.
Torsten's comment on Christian's post at
http://www.christianposta.com/blog/?p=273 gives a detailed description of why
you're seeing this, and of two work-arounds available to you (disabling
per-destination memory limits and setting cursorMemoryHighWaterMark to a
percentage that is less than the ratio of the per-destination memory limit to
the entire-broker memory limit. Hopefully one of those options is workable for
you.
Both Christian's blog post and Torsten's comments make it clear that this is
known and expected behavior. That's not to say that that's the best possible
way for it to work, or that the change you're requesting shouldn't be
implemented; I think that it should, as long as the people who know this code
well can assure themselves that it doesn't mess up anything else. But it makes
this an Improvement, not a Bug, so you should change the issue type to
Improvement.
If you want it to have the best chance of getting implemented, I'd recommend
you reword the title and description to focus on the improvement to be made,
not the unwanted behavior that results from not making the change. It also
sounds like you're proposing changing the implementation of
AbstractPendingMessageCursor.hasSpace(); is that right? Since you have an
implementation in mind, I'd encourage you to create and attach the patch you're
proposing; an already-implemented patch is going to be the most likely to get
implemented because it's the least work for whoever might take this on.
> Topic persistent message publishing is blocked by hitting 100% of
> per-destination memory limit if there's any durable subscriber connected but
> not consuming.
> -------------------------------------------------------------------------------------------------------------------------------------------------------------
>
> Key: AMQ-4666
> URL: https://issues.apache.org/jira/browse/AMQ-4666
> Project: ActiveMQ
> Issue Type: Bug
> Components: Broker
> Affects Versions: 5.7.0
> Reporter: Jaewoong Choi
> Attachments: MemoryLimitTest.java
>
>
> Failing scenario:
> 1. Embedded broker starts with the following configurations:
> - persistent = true,
> - systemUsage.memoryUsage.limit = 10*1024*1024 // 10mb broker main memory
> limit
> - destinationPolicy.policyEntry.memoryLimit = 1*1024*1024 // 1mb
> per-destination memory limit
> 2. Create a topic durable subscription with prefetchLimit=0.
> 3. Create a topic publisher and publish persistent 400kb messages.
> 4. (Problem) After publishing 3 messages successfully, PFC kicks in and the
> above topic publisher gets blocked its publishing.
> At step #4, the expectation is not seeing any publisher blocking for the
> persistent message publishing until the store limit is reached. How come the
> persistent message publishing is limited by 100% memory full?
> Per the code inspection, this is because the store cursor of the topic
> durable subscriber (i.e. TopicStorePrefetch) is working with the main
> broker's memory limit, not with the per-destination memory limit. Hence, it
> keeps increasing broker main memory usage over the per-destination memory
> limit and after it reached 100% of per-destination limit, PFC kicked in.
> I verified that the above scenario went through well if I fix the store
> cursor to use/refer-to the per-destination memory usage along with its
> pending list (cache) management.
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