[
https://issues.apache.org/jira/browse/HBASE-5155?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13183898#comment-13183898
]
stack commented on HBASE-5155:
------------------------------
Ugh, I wrote a comment and lost it.
So, when you say above that '-> The tables and its regions are deleted
including R1, D1 and D2.. (So META is cleaned)', you are saying that this
happens AFTER SSH has scanned .META. and that we're doing the region processing
AFTER the deletes (I was going to say its odd that we fixup a daughter when
parent is missing but checking .META. and filesystem before each daughter fixup
would still have a hole during which a delete could come in....)
On keeping a TableState.ENABLED up in zk, that could work (Can't remember why
didn't do it that way originally -- only thought is that was trying to save on
the state kept up in zk which is a pretty pathetic reason). You'll need to add
an AM.isEnabledTable method to match the isDisabledTable, etc., stuff that is
already there. Good stuff Ram.
> ServerShutDownHandler And Disable/Delete should not happen parallely leading
> to recreation of regions that were deleted
> -----------------------------------------------------------------------------------------------------------------------
>
> Key: HBASE-5155
> URL: https://issues.apache.org/jira/browse/HBASE-5155
> Project: HBase
> Issue Type: Bug
> Components: master
> Affects Versions: 0.90.4
> Reporter: ramkrishna.s.vasudevan
> Priority: Blocker
>
> ServerShutDownHandler and disable/delete table handler races. This is not an
> issue due to TM.
> -> A regionserver goes down. In our cluster the regionserver holds lot of
> regions.
> -> A region R1 has two daughters D1 and D2.
> -> The ServerShutdownHandler gets called and scans the META and gets all the
> user regions
> -> Parallely a table is disabled. (No problem in this step).
> -> Delete table is done.
> -> The tables and its regions are deleted including R1, D1 and D2.. (So META
> is cleaned)
> -> Now ServerShutdownhandler starts to processTheDeadRegion
> {code}
> if (hri.isOffline() && hri.isSplit()) {
> LOG.debug("Offlined and split region " + hri.getRegionNameAsString() +
> "; checking daughter presence");
> fixupDaughters(result, assignmentManager, catalogTracker);
> {code}
> As part of fixUpDaughters as the daughers D1 and D2 is missing for R1
> {code}
> if (isDaughterMissing(catalogTracker, daughter)) {
> LOG.info("Fixup; missing daughter " + daughter.getRegionNameAsString());
> MetaEditor.addDaughter(catalogTracker, daughter, null);
> // TODO: Log WARN if the regiondir does not exist in the fs. If its not
> // there then something wonky about the split -- things will keep going
> // but could be missing references to parent region.
> // And assign it.
> assignmentManager.assign(daughter, true);
> {code}
> we call assign of the daughers.
> Now after this we again start with the below code.
> {code}
> if (processDeadRegion(e.getKey(), e.getValue(),
> this.services.getAssignmentManager(),
> this.server.getCatalogTracker())) {
> this.services.getAssignmentManager().assign(e.getKey(), true);
> {code}
> Now when the SSH scanned the META it had R1, D1 and D2.
> So as part of the above code D1 and D2 which where assigned by fixUpDaughters
> is again assigned by
> {code}
> this.services.getAssignmentManager().assign(e.getKey(), true);
> {code}
> Thus leading to a zookeeper issue due to bad version and killing the master.
> The important part here is the regions that were deleted are recreated which
> i think is more critical.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators:
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira
