[fix][broker] fix delete_when_subscriptions_caught_up doesn't work while have active consumers #18283
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…ile have active consumers
codelipenghui
added
type/bug
codelipenghui
requested review from
eolivelli,
Jason918,
315157973,
mattisonchao and
Technoboy-
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@@ Coverage Diff @@
## master #18283 +/- ##
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+ Coverage 38.97% 51.91% +12.94%
+ Complexity 8311 7411 -900
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Files 683 400 -283
Lines 67325 43679 -23646
Branches 7217 4483 -2734
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- Hits 26239 22677 -3562
+ Misses 38079 18562 -19517
+ Partials 3007 2440 -567
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| // 2. We want to kick out everyone and forcefully delete the topic. | ||
| // In this case, we shouldn't care if the usageCount is 0 or not, just proceed | ||
| if (currentUsageCount() == 0 || (closeIfClientsConnected && !failIfHasSubscriptions)) { | ||
| if (currentUsageCount() == 0) { |
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Seems we need to keep the original condition (closeIfClientsConnected && !failIfHasSubscriptions))
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I feel the current code is correct. Because we have called disconnection operation before. If there are still any connections at the current time, it means that a new connection has come in, we should consider that there is a concurrency problem and give up deleting the topic.
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Yes, you are right @poorbarcode
The closeIfClientsConnected and failIfHasSubscriptions is validated before we reach here. It looks like duplicated validation.
| // 2. We want to kick out everyone and forcefully delete the topic. | ||
| // In this case, we shouldn't care if the usageCount is 0 or not, just proceed | ||
| if (currentUsageCount() == 0 || (closeIfClientsConnected && !failIfHasSubscriptions)) { | ||
| if (currentUsageCount() == 0) { |
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I feel the current code is correct. Because we have called disconnection operation before. If there are still any connections at the current time, it means that a new connection has come in, we should consider that there is a concurrency problem and give up deleting the topic.
| } else if (!closeIfClientsConnected && currentUsageCount() != 0 && !failIfHasBacklogs) { | ||
| return FutureUtil.failedFuture(new TopicBusyException( | ||
| "Topic has " + currentUsageCount() + " connected producers/consumers")); |
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It needs to fail as long as there are connections, so it has nothing to do with !failIfHasBacklogs.
Or if failIfHasBacklogs is triggered, the error message returned should not be like this
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Hi @315157973
When failIfHasBacklogs is true, the expected behavior is that:
- failure of any producer exists
- if any consumer exists, close connections
Actually, the code should be like this:
if ( !closeIfClientsConnected && currentUsageCount() ){
fail...
} else if ( !closeIfClientsConnected !failIfHasBacklogs && anyProducerExists() ){
fail...
}This code may not be easy to understand from the context, but the logic is correct
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There is also a concurrency problem that may lead to the incorrect deletion of existing producer topics. E.g:
checkGC |
new producer registry |
|---|---|
| ensure no producer exists | |
delete topic ( false, true, false) |
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| ensure no backlog | |
| new producer registry | |
| fence topic | |
| disconnect all clients | |
| delete topic |
The above flow shows the case: producer exists but the topic is deleted. Would it be better to add a double-check？
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We have write lock here https://github.com/apache/pulsar/pull/18283/files#diff-5edf14cc6f25857d0cfdd26b2d3b3141230ecfb0dfa95aebf7583fd76ede4c4bR1161
Ah, yes you are right
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could you please cherry-pick this PR to branch-2.9? thanks. |
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#18320 has cherry-picked this one to branch-2.11 |
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f5c9354 cherry-picked to branch-2.10 |
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3cf167a cherry-picked to branch-2.9 |
Motivation
The current behavior for the
delete_when_subscriptions_caught_upstrategy is not expected. The active consumer will not be closed even if users enabledelete_when_subscriptions_caught_upand there are no backlogs for the topic.It should be the part that #6077 has missed. And Sijie has mentioned in the comment #6077 (review).
To correct the behavior of
delete_when_subscriptions_caught_upModifications
Close active consumers if
delete_when_subscriptions_caught_upis applied and there are no backlogs for the topic. So that the topic can be cleaned up properly by the topic GC thread.Verifying this change
Updated the existing test.
Does this pull request potentially affect one of the following parts:
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Documentation
docdoc-requireddoc-not-neededdoc-completeMatching PR in forked repository
PR in forked repository: codelipenghui#17