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Konstantin Boudnik commented on HDFS-4452: ------------------------------------------ The patch looks mostly good. A few minor comments: - the logger in the class should be initialized for {{TestAddBlockRetry}}, not {{TestFSDirectory}} - formatting only change {noformat} LocatedBlock getAdditionalBlock(String src, - String clientName, - ExtendedBlock previous, - HashMap<Node, Node> excludedNodes - ) + String clientName, + ExtendedBlock previous, + HashMap<Node, Node> excludedNodes) {noformat} Test is failing without the corresponding change in the code, so it seems right on the money. +1 > getAdditionalBlock() can create multiple blocks if the client times out and > retries. > ------------------------------------------------------------------------------------ > > Key: HDFS-4452 > URL: https://issues.apache.org/jira/browse/HDFS-4452 > Project: Hadoop HDFS > Issue Type: Bug > Components: namenode > Affects Versions: 2.0.2-alpha > Reporter: Konstantin Shvachko > Assignee: Konstantin Shvachko > Priority: Critical > Attachments: getAdditionalBlock.patch, getAdditionalBlock.patch, > TestAddBlockRetry.java > > > HDFS client tries to addBlock() to a file. If NameNode is busy the client can > timeout and will reissue the same request again. The two requests will race > with each other in {{FSNamesystem.getAdditionalBlock()}}, which can result in > creating two new blocks on the NameNode while the client will know of only > one of them. This eventually results in {{NotReplicatedYetException}} because > the extra block is never reported by any DataNode, which stalls file creation > and puts it in invalid state with an empty block in the middle. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira