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https://issues.apache.org/jira/browse/HBASE-5270?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13219354#comment-13219354
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stack commented on HBASE-5270:
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@Chunhui You have a new method splitLogIfOnline which will split the log if the
server was online. Why do you not expire the server? (You remove the
expireIfOnline method).
Now we have this initializing state, do you think we should also stop the
processing of expired servers during this startup phase and instead queue them
up for processing after the master is up? Could do that in another issue maybe
since this issue has been going on too long and your patch is at least an
improvement on what we currently have (This startup sequence needs a big
refactor IMO -- it is way too complicated figuring the sequence in which stuff
runs).
Are there still holes? For example, say the .META. server crashes AFTER we've
verified it up in assignRootAndMeta but before we get to do a scan of .META. to
rebuild user regions list. Could .META. be assigned w/o log splitting
finishing? (I don't think so... .META. would be offline until the
servershutdown handler ran and it would first split logs).
Good stuff.
> Handle potential data loss due to concurrent processing of processFaileOver
> and ServerShutdownHandler
> -----------------------------------------------------------------------------------------------------
>
> Key: HBASE-5270
> URL: https://issues.apache.org/jira/browse/HBASE-5270
> Project: HBase
> Issue Type: Sub-task
> Components: master
> Reporter: Zhihong Yu
> Assignee: chunhui shen
> Fix For: 0.92.1, 0.94.0
>
> Attachments: 5270-90-testcase.patch, 5270-90-testcasev2.patch,
> 5270-90.patch, 5270-90v2.patch, 5270-90v3.patch, 5270-testcase.patch,
> 5270-testcasev2.patch, hbase-5270.patch, hbase-5270v2.patch,
> hbase-5270v4.patch, hbase-5270v5.patch, hbase-5270v6.patch,
> hbase-5270v7.patch, hbase-5270v8.patch, sampletest.txt
>
>
> This JIRA continues the effort from HBASE-5179. Starting with Stack's
> comments about patches for 0.92 and TRUNK:
> Reviewing 0.92v17
> isDeadServerInProgress is a new public method in ServerManager but it does
> not seem to be used anywhere.
> Does isDeadRootServerInProgress need to be public? Ditto for meta version.
> This method param names are not right 'definitiveRootServer'; what is meant
> by definitive? Do they need this qualifier?
> Is there anything in place to stop us expiring a server twice if its carrying
> root and meta?
> What is difference between asking assignment manager isCarryingRoot and this
> variable that is passed in? Should be doc'd at least. Ditto for meta.
> I think I've asked for this a few times - onlineServers needs to be
> explained... either in javadoc or in comment. This is the param passed into
> joinCluster. How does it arise? I think I know but am unsure. God love the
> poor noob that comes awandering this code trying to make sense of it all.
> It looks like we get the list by trawling zk for regionserver znodes that
> have not checked in. Don't we do this operation earlier in master setup? Are
> we doing it again here?
> Though distributed split log is configured, we will do in master single
> process splitting under some conditions with this patch. Its not explained in
> code why we would do this. Why do we think master log splitting 'high
> priority' when it could very well be slower. Should we only go this route if
> distributed splitting is not going on. Do we know if concurrent distributed
> log splitting and master splitting works?
> Why would we have dead servers in progress here in master startup? Because a
> servershutdownhandler fired?
> This patch is different to the patch for 0.90. Should go into trunk first
> with tests, then 0.92. Should it be in this issue? This issue is really hard
> to follow now. Maybe this issue is for 0.90.x and new issue for more work on
> this trunk patch?
> This patch needs to have the v18 differences applied.
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