[
https://issues.apache.org/jira/browse/BOOKKEEPER-447?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13531304#comment-13531304
]
Sijie Guo commented on BOOKKEEPER-447:
--------------------------------------
CacheCallback is required for a skip list solution in BOOKKEEPER-432, because
you had to flush the buffered entries to make spaces for newly added entries.
You could use CacheCallback here to notify sync thread to force a full flush or
just force flush entry logger, after that it is safe to force flush an ledger
to steal its ledger cache page. I think it would be better than a busy-waiting,
although it still not so perfect.
> Bookie can fail to recover if index pages flushed before ledger flush
> acknowledged
> ----------------------------------------------------------------------------------
>
> Key: BOOKKEEPER-447
> URL: https://issues.apache.org/jira/browse/BOOKKEEPER-447
> Project: Bookkeeper
> Issue Type: Bug
> Components: bookkeeper-server
> Affects Versions: 4.2.0
> Reporter: Yixue (Andrew) Zhu
> Assignee: Ivan Kelly
> Fix For: 4.2.0, 4.1.1
>
> Attachments:
> 0001-BOOKKEEPER-447-LedgerCacheImpl-waits-on-lock-object-.patch,
> 0001-BOOKKEEPER-447-LedgerCacheImpl-waits-on-lock-object-.patch,
> 0001-BOOKKEEPER-447-LedgerCacheImpl-waits-on-semaphore-no.patch,
> BOOKKEEPER-447.diff, perf.png
>
>
> Bookie index page steal (LedgerCacheImpl::grabCleanPage) can cause index file
> to reflect unacknowledged entries (due to flushLedger). Suppose ledger and
> entry fail to flush due to Bookkeeper server crash, it will cause ledger
> recovery not able to use the bookie afterward, due to
> InterleavedStorageLedger::getEntry throws IOException.
> If the ackSet bookies all experience this problem (DC environment), the
> ledger will not be able to recover.
> The problem here essentially a violation of WAL. One reasonable fix is to
> track ledger flush progress (either per-ledger entry, or per-topic message).
> Do not flush index pages which tracks entries whose ledger (log) has not been
> flushed.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira
