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Hairong Kuang commented on HDFS-101: ------------------------------------ By simply looking at your client-side log, it seems to me that the datanode sent an ack with two fields but the client expects an ack with 3 fields. Could you please create a jira and post logs there? Thanks! > DFS write pipeline : DFSClient sometimes does not detect second datanode > failure > --------------------------------------------------------------------------------- > > Key: HDFS-101 > URL: https://issues.apache.org/jira/browse/HDFS-101 > Project: Hadoop HDFS > Issue Type: Bug > Components: data-node > Affects Versions: 0.20.1, 0.20-append > Reporter: Raghu Angadi > Assignee: Hairong Kuang > Priority: Blocker > Fix For: 0.20.2, 0.20-append, 0.21.0 > > Attachments: HDFS-101_20-append.patch, detectDownDN-0.20.patch, > detectDownDN1-0.20.patch, detectDownDN2.patch, > detectDownDN3-0.20-yahoo.patch, detectDownDN3-0.20.patch, > detectDownDN3.patch, hdfs-101-branch-0.20-append-cdh3.txt, hdfs-101.tar.gz, > pipelineHeartbeat.patch, pipelineHeartbeat_yahoo.patch > > > When the first datanode's write to second datanode fails or times out > DFSClient ends up marking first datanode as the bad one and removes it from > the pipeline. Similar problem exists on DataNode as well and it is fixed in > HADOOP-3339. From HADOOP-3339 : > "The main issue is that BlockReceiver thread (and DataStreamer in the case of > DFSClient) interrupt() the 'responder' thread. But interrupting is a pretty > coarse control. We don't know what state the responder is in and interrupting > has different effects depending on responder state. To fix this properly we > need to redesign how we handle these interactions." > When the first datanode closes its socket from DFSClient, DFSClient should > properly read all the data left in the socket.. Also, DataNode's closing of > the socket should not result in a TCP reset, otherwise I think DFSClient will > not be able to read from the socket. -- This message is automatically generated by JIRA. For more information on JIRA, see: http://www.atlassian.com/software/jira