NickyYe commented on pull request #2562: URL: https://github.com/apache/hadoop/pull/2562#issuecomment-748285060
> ConcurrentModificationException Thanks for looking. If there are only 2 datanodes in outOfServiceNodeBlocks and the first one is removed, then it will be a dead loop on the second datanode. If there are more than 2 datanodes and the first one is removed, there will be a ConcurrentModificationException. I see both two cases in our prod very often. This issue only happens when remove (dnAdmin.stopMaintenance(dn);). By outOfServiceNodeBlocks.put(dn, blocks), it only updates the value, so Cyclic Iteration won't be affected ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
