[ https://issues.apache.org/jira/browse/HDFS-8964?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14729506#comment-14729506 ]
Colin Patrick McCabe commented on HDFS-8964: -------------------------------------------- +1. Thanks, [~zhz]. > Provide max TxId when validating in-progress edit log files > ----------------------------------------------------------- > > Key: HDFS-8964 > URL: https://issues.apache.org/jira/browse/HDFS-8964 > Project: Hadoop HDFS > Issue Type: Bug > Components: journal-node, namenode > Affects Versions: 2.7.1 > Reporter: Zhe Zhang > Assignee: Zhe Zhang > Attachments: HDFS-8964.00.patch, HDFS-8964.01.patch, > HDFS-8964.02.patch, HDFS-8964.03.patch, HDFS-8964.04.patch, > HDFS-8964.05.patch, HDFS-8964.06.patch > > > NN/JN validates in-progress edit log files in multiple scenarios, via > {{EditLogFile#validateLog}}. The method scans through the edit log file to > find the last transaction ID. > However, an in-progress edit log file could be actively written to, which > creates a race condition and causes incorrect data to be read (and later we > attempt to interpret the data as ops). > Currently {{validateLog}} is used in 3 places: > # NN {{getEditsFromTxid}} > # JN {{getEditLogManifest}} > # NN/JN {{recoverUnfinalizedSegments}} > In the first two scenarios we should provide a maximum TxId to validate in > the in-progress file. The 3rd scenario won't cause a race condition because > only non-current in-progress edit log files are validated. > {{validateLog}} is actually only used with in-progress files, and could use a > better name and Javadoc. -- This message was sent by Atlassian JIRA (v6.3.4#6332)