[ https://issues.apache.org/jira/browse/HDFS-10301?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15485884#comment-15485884 ]
Vinitha Reddy Gankidi commented on HDFS-10301: ---------------------------------------------- Upon thorough investigation of heartbeat logic I have verified that unreported storages do get removed without any code change. Attached patch 014 eliminates the state and the zombie storage removal logic introduced in HDFS-7960. I have added a unit test that verifies that when a DN storage with blocks is removed, this storage is removed from the DatanodeDescriptor as well and does not linger forever. Unreported storages are marked as FAILED in {{updateHeartbeatState}} method when {{checkFailedStorages}} is true. Thus when a DN storage is removed, it will be marked as FAILED in the next heartbeat. The storage removal happens in 2 steps after that (Refer Step 2 & 3 in https://issues.apache.org/jira/browse/HDFS-10301?focusedCommentId=15427387&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-15427387). The test {{testRemovingStorageDoesNotProduceZombies}} introduced in HDFS-7960 passes by reducing the heartbeat recheck interval so that the test doesn't timeout. By default, the Heartbeat Manager removes blocks associated with failed storages every 5 minutes. I have ignored {{testProcessOverReplicatedAndMissingStripedBlock}} in this patch. Please refer to HDFS-10854 for more details. > BlockReport retransmissions may lead to storages falsely being declared > zombie if storage report processing happens out of order > -------------------------------------------------------------------------------------------------------------------------------- > > Key: HDFS-10301 > URL: https://issues.apache.org/jira/browse/HDFS-10301 > Project: Hadoop HDFS > Issue Type: Bug > Components: namenode > Affects Versions: 2.6.1 > Reporter: Konstantin Shvachko > Assignee: Vinitha Reddy Gankidi > Priority: Critical > Fix For: 2.7.4 > > Attachments: HDFS-10301.002.patch, HDFS-10301.003.patch, > HDFS-10301.004.patch, HDFS-10301.005.patch, HDFS-10301.006.patch, > HDFS-10301.007.patch, HDFS-10301.008.patch, HDFS-10301.009.patch, > HDFS-10301.01.patch, HDFS-10301.010.patch, HDFS-10301.011.patch, > HDFS-10301.012.patch, HDFS-10301.013.patch, HDFS-10301.branch-2.7.patch, > HDFS-10301.branch-2.patch, HDFS-10301.sample.patch, zombieStorageLogs.rtf > > > When NameNode is busy a DataNode can timeout sending a block report. Then it > sends the block report again. Then NameNode while process these two reports > at the same time can interleave processing storages from different reports. > This screws up the blockReportId field, which makes NameNode think that some > storages are zombie. Replicas from zombie storages are immediately removed, > causing missing blocks. -- This message was sent by Atlassian JIRA (v6.3.4#6332) --------------------------------------------------------------------- To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org