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https://issues.apache.org/jira/browse/CASSANDRA-7000?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13964853#comment-13964853
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Yuki Morishita commented on CASSANDRA-7000:
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Ping, [~thobbs] and [~benedict].
Snapshot repair opens snapshotted SSTables, creates MT against them, and close
them when it's done.
While doing so, validation compaction does not acquire reference since SSTables
are from snapshot.
Now, CASSANDRA-6912 introduced tidy method which is called both from close and
releaseReference assumes reference is 0, thus causing AE when doing repair(and
breaking repair dtest. see CASSANDRA-7005).
Patch works for repair scenario, but foundamentally I'm not sure this is the
way to go. Shouldn't SSTableReader be closable regardless of reference acuired?
> Assertion in SSTableReader during repair.
> -----------------------------------------
>
> Key: CASSANDRA-7000
> URL: https://issues.apache.org/jira/browse/CASSANDRA-7000
> Project: Cassandra
> Issue Type: Bug
> Reporter: Ben Chan
> Assignee: Ben Chan
> Attachments: sstablereader-assertion-bisect-helper,
> sstablereader-assertion-bisect-helper-v2, sstablereader-assertion.patch
>
>
> I ran a {{git bisect run}} using the attached bisect script. Repro code:
> {noformat}
> # 5dfe241: trunk as of my git bisect run
> # 345772d: empirically determined "good" commit.
> git bisect start 5dfe241 345772d
> git bisect run ./sstablereader-assertion-bisect-helper-v2
> {noformat}
> The first failing commit is 5ebadc1 (first parent of {{refs/bisect/bad}}).
> Prior to 5ebadc1, SSTableReader#close() never checked reference count. After
> 5ebadc1, there was an assertion for {{references.get() == 0}}. However, since
> the reference count is initialized to 1, a SSTableReader#close() was always
> guaranteed to either throw an AssertionError or to be a second call to
> SSTableReader#tidy() on the same SSTableReader.
> The attached patch chooses an in-between behavior. It requires the reference
> count to match the initialization value of 1 for SSTableReader#close(), and
> the same behavior as 5ebadc1 otherwise.
> This allows repair to finish successfully, but I'm not 100% certain what the
> desired behavior is for SSTableReader#close(). Should it close without regard
> to reference count, as it did pre-5ebadc1?
> Edit: accidentally uploaded a flawed version of
> {{sstablereader-assertion-bisect-helper}} (doesn't work out-of-the-box with
> {{git bisect}}).
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