[ https://issues.apache.org/jira/browse/HBASE-2312?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
stack updated HBASE-2312: ------------------------- Status: Patch Available (was: Open) Submitting patch; v2 is up on review.hbase.org. > Possible data loss when RS goes into GC pause while rolling HLog > ---------------------------------------------------------------- > > Key: HBASE-2312 > URL: https://issues.apache.org/jira/browse/HBASE-2312 > Project: HBase > Issue Type: Bug > Components: master, regionserver > Affects Versions: 0.20.3 > Reporter: Karthik Ranganathan > Assignee: Nicolas Spiegelberg > Fix For: 0.90.0 > > > There is a very corner case when bad things could happen(ie data loss): > 1) RS #1 is going to roll its HLog - not yet created the new one, old one > will get no more writes > 2) RS #1 enters GC Pause of Death > 3) Master lists HLog files of RS#1 that is has to split as RS#1 is dead, > starts splitting > 4) RS #1 wakes up, created the new HLog (previous one was rolled) and > appends an edit - which is lost > The following seems like a possible solution: > 1) Master detects RS#1 is dead > 2) The master renames the /hbase/.logs/<regionserver name> directory to > something else (say /hbase/.logs/<regionserver name>-dead) > 3) Add mkdir support (as opposed to mkdirs) to HDFS - so that a file > create fails if the directory doesn't exist. Dhruba tells me this is very > doable. > 4) RS#1 comes back up and is not able create the new hlog. It restarts > itself. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.