[ https://issues.apache.org/jira/browse/HDFS-1057?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
sam rash updated HDFS-1057: --------------------------- Attachment: hdfs-1057-trunk-2.txt 1. new endOffset calc includes determining if in-memory checksum is needed 2. added methods to RBW only to set/get last checksum and data length -track this dataLength separate as setBytesOnDisk may be called independently and make the length/byte[] not match (in theory bytes on disk *could* be set to more and we still want a checksum + the corresponding length kept) 3. appropriate changes around waiting for start + length did not remove all replicaVisibleLength uses yet--want to clarify what to replace them with in pre-existing code. > Concurrent readers hit ChecksumExceptions if following a writer to very end > of file > ----------------------------------------------------------------------------------- > > Key: HDFS-1057 > URL: https://issues.apache.org/jira/browse/HDFS-1057 > Project: Hadoop HDFS > Issue Type: Sub-task > Components: data-node > Affects Versions: 0.21.0, 0.22.0, 0.20-append > Reporter: Todd Lipcon > Assignee: sam rash > Priority: Blocker > Attachments: conurrent-reader-patch-1.txt, > conurrent-reader-patch-2.txt, conurrent-reader-patch-3.txt, > hdfs-1057-trunk-1.txt, hdfs-1057-trunk-2.txt > > > In BlockReceiver.receivePacket, it calls replicaInfo.setBytesOnDisk before > calling flush(). Therefore, if there is a concurrent reader, it's possible to > race here - the reader will see the new length while those bytes are still in > the buffers of BlockReceiver. Thus the client will potentially see checksum > errors or EOFs. Additionally, the last checksum chunk of the file is made > accessible to readers even though it is not stable. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.