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https://issues.apache.org/jira/browse/HBASE-5270?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13228174#comment-13228174
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stack commented on HBASE-5270:
------------------------------
@Chunhui Sorry. I thought I'd provided comments already on this issue. It
seems like my comments were lost by me.
So, to me its odd that we disable one handler only; i.e.
serverShutdownHandlerEnabled
If a split or a close or an open come in while master is initializing, won't
that mess up our view of the cluster? Why not turn all all handlers on
initialization queuing tasks?
I would tolerate our doing this in another issue if thats what you think we
should do.
Who needs this:
{code}
+ void joinCluster() throws IOException, KeeperException, InterruptedException
{
{code}
I think you need to add comments explaining what deadNotExpired servers are.
Its a weird concept and folks can go read over where they are defined but it
could help if up in HMaster and AssingmentManager where they are used, you
explain what they are to help those coming after trying to figure whats going
on. Maybe point at the explaination over in ServerManager?
{code}
+ Iterator<ServerName> serverIterator=deadNotExpiredServers.iterator();
{code}
Notice how there are spaces around operators in all of the surrounding code.
What happens if when we call expireDeadNotExpiredServers, the server has
already been expired?
Why do the following:
{code}
+ serverShutdownHandlerEnabled = true;
+ this.serverManager.expireDeadNotExpiredServers();
{code}
.. then in expireDeadNotExpiredServers, first thing we do is check if
serverShutdownHandlerEnabled is true or not. Under what cirumstance would it
not be true if we just set it? This is only place we call
expireDeadNotExpiredServers.
In general I'm in favor of committing this patch because it has a test. Thanks
Chunhui.
> 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: 0.92.2
>
> 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-5270v10.patch,
> hbase-5270v2.patch, hbase-5270v4.patch, hbase-5270v5.patch,
> hbase-5270v6.patch, hbase-5270v7.patch, hbase-5270v8.patch,
> hbase-5270v9.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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