fix: No need to trigger ensembleChangeLoop if all failed bookies are not in current ensemble

[M1eyu2018]

Descriptions of the changes in this PR:

No need to trigger ensembleChangeLoop if all failed bookies are not in current ensemble.

Motivation

Fix the bug issue.
#4261

Changes

No need to trigger ensembleChangeLoop if all failed bookies are not in current ensemble.

Master Issue: #

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[hangc0276]

To fix this issue, check the delayedWriteFailedBookies before replace can solve this problem. But it is better to failed the write request when the write request received failure callback.

bookkeeper/bookkeeper-server/src/main/java/org/apache/bookkeeper/proto/PerChannelBookieClient.java

Lines 1210 to 1212 in e6b4154

	} else {
	nettyOpLogger.registerFailedEvent(MathUtils.elapsedNanos(startTime), TimeUnit.NANOSECONDS);
	}

@horizonzy tested this solution, and it works.

[horizonzy]

#4285 can fix the problem, but this PR is also good for avoiding the unnecessary ensembleChangeLoop. I think this is useful.

[M1eyu2018]

@hangc0276 @horizonzy I have added a unit for this PR. PTAL

[lhotari]

I this related to #4194? /cc @shustsud

[hezhangjian]

LGTM

[hezhangjian]

@dlg99 @hangc0276 @eolivelli PTAL, thanks

[hangc0276]

We need to set changingEnsemble = true when entering the else code block to avoid a potential race condition. If all the bookies in the toReplace set do not exist in the current ensemble, set changingEnsemble back to false.

What's more, please add a comment to explain why we need this logic. thanks.

[hangc0276]

@M1eyu2018 Thanks for your contribution. Would you please help check the failed tests? Thanks.

[hezhangjian]

Sorry I didn't remember why I close this last week. It maybe a mis-operation. @M1eyu2018 Would you please help check the failed tests? Thanks.

[M1eyu2018]

Sorry I didn't remember why I close this last week. It maybe a mis-operation. @M1eyu2018 Would you please help check the failed tests? Thanks.

OK, I will check as soon as possible.

[M1eyu2018]

@hangc0276 @shoothzj
I have checked the failed tests.