Prevent double flush due to race in SingleDirectoryDbLedgerStorage #4305
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Disclaimer: I am not very familiar with this code, so please review carefully.
Motivation
We use the
isFlushOngoing
and thehasFlushBeenTriggered
atomic booleans to prevent concurrent flushes. See:bookkeeper/bookkeeper-server/src/main/java/org/apache/bookkeeper/bookie/storage/ldb/SingleDirectoryDbLedgerStorage.java
Lines 514 to 530 in 2986e04
By my reading of the code, it seems there is a brief period of time where the calling code will think it is valid to flush, even though there is a flush in progress.
Changes
In the
SingleDirectoryDbLedgerStorage#swapWriteCache
method modified by this PR, I propose a change to setisFlushOngoing
to true before settinghasFlushBeenTriggered
to false.Master Issue: none