Details
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Bug
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Status: Resolved
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Critical
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Resolution: Duplicate
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2.4.1
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None
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None
Description
We got a severe datalose due to the fact that namenode didn't recognized block it thinks exist are not actually exist on the datanodes. The senario is something as follows:
- A disk fails on one of the datanodes
- The datanode is forced to decommiss and shut down
- The disk is replaced and datanode is back again
- fsck shows everything is fine
- Repeat 1-4 for few weeks
- Restart the namenode
- It suddenly sees tens of thousands under-replicated blocks and hundreds missing blocks
During the next disk failure we analysed situation a bit more and found particular block on particular datanode that is missing: there is no file for block and if we try to read it, we got
java.io.IOException: Got error for OP_READ_BLOCK, self=/XXX:33817, remote=XXX/X.X.X.X:50010, for file XXX/X.X.X.X:50010:BP-879324367-YYY-1404837025894:1083356878, for pool BP-879324367-YYY-1404837025894 block 1083356878_9644290
We restarted the datanode and in the log we can see that it did scan all the directories and send the report to namenode:
2014-11-27 17:06:34,174 INFO [DataNode: [[[DISK]file:/mnt/hadoop/0/dfs/data/, [DISK]file:/mnt/hadoop/1/dfs/data/, [DISK]file:/mnt/hadoop/2/dfs/data/]] heartbeating to /YYY:8020] FsDatasetImpl - Adding block pool BP-879324367-YYY-1404837025894 2014-11-27 17:06:34,175 INFO [Thread-41] FsDatasetImpl - Scanning block pool BP-879324367-YYY-1404837025894 on volume /mnt/hadoop/0/dfs/data/current... 2014-11-27 17:06:34,176 INFO [Thread-43] FsDatasetImpl - Scanning block pool BP-879324367-YYY-1404837025894 on volume /mnt/hadoop/2/dfs/data/current... 2014-11-27 17:06:34,176 INFO [Thread-42] FsDatasetImpl - Scanning block pool BP-879324367-YYY-1404837025894 on volume /mnt/hadoop/1/dfs/data/current... 2014-11-27 17:06:34,279 INFO [Thread-42] FsDatasetImpl - Cached dfsUsed found for /mnt/hadoop/1/dfs/data/current/BP-879324367-YYY-1404837025894/current: 62677866794 2014-11-27 17:06:34,282 INFO [Thread-42] FsDatasetImpl - Time taken to scan block pool BP-879324367-YYY-1404837025894 on /mnt/hadoop/1/dfs/data/current: 105ms 2014-11-27 17:06:34,744 INFO [Thread-41] FsDatasetImpl - Cached dfsUsed found for /mnt/hadoop/0/dfs/data/current/BP-879324367-YYY-1404837025894/current: 2465590681232 2014-11-27 17:06:34,744 INFO [Thread-41] FsDatasetImpl - Time taken to scan block pool BP-879324367-YYY-1404837025894 on /mnt/hadoop/0/dfs/data/current: 568ms 2014-11-27 17:06:34,856 INFO [Thread-43] FsDatasetImpl - Cached dfsUsed found for /mnt/hadoop/2/dfs/data/current/BP-879324367-YYY-1404837025894/current: 2475580099468 2014-11-27 17:06:34,857 INFO [Thread-43] FsDatasetImpl - Time taken to scan block pool BP-879324367-YYY-1404837025894 on /mnt/hadoop/2/dfs/data/current: 680ms 2014-11-27 17:06:34,857 INFO [DataNode: [[[DISK]file:/mnt/hadoop/0/dfs/data/, [DISK]file:/mnt/hadoop/1/dfs/data/, [DISK]file:/mnt/hadoop/2/dfs/data/]] heartbeating to /YYY:8020] 2014-11-27 17:06:34,858 INFO [Thread-44] FsDatasetImpl - Adding replicas to map for block pool BP-879324367-YYY-1404837025894 on volume /mnt/hadoop/0/dfs/data/current... 2014-11-27 17:06:34,890 INFO [Thread-46] FsDatasetImpl - Adding replicas to map for block pool BP-879324367-YYY-1404837025894 on volume /mnt/hadoop/2/dfs/data/current... 2014-11-27 17:06:34,890 INFO [Thread-45] FsDatasetImpl - Adding replicas to map for block pool BP-879324367-YYY-1404837025894 on volume /mnt/hadoop/1/dfs/data/current... 2014-11-27 17:06:34,961 INFO [Thread-45] FsDatasetImpl - Time to add replicas to map for block pool BP-879324367-YYY-1404837025894 on volume /mnt/hadoop/1/dfs/data/current: 70ms 2014-11-27 17:06:36,083 INFO [Thread-44] FsDatasetImpl - Time to add replicas to map for block pool BP-879324367-YYY-1404837025894 on volume /mnt/hadoop/0/dfs/data/current: 1193ms 2014-11-27 17:06:36,162 INFO [Thread-46] FsDatasetImpl - Time to add replicas to map for block pool BP-879324367-YYY-1404837025894 on volume /mnt/hadoop/2/dfs/data/current: 1271ms 2014-11-27 17:06:36,162 INFO [DataNode: [[[DISK]file:/mnt/hadoop/0/dfs/data/, [DISK]file:/mnt/hadoop/1/dfs/data/, [DISK]file:/mnt/hadoop/2/dfs/data/]] heartbeating to /YYY:8020] FsDatasetImpl - Total time to add all replicas to map: 1304ms 2014-11-27 17:06:36,167 INFO [DataNode: [[[DISK]file:/mnt/hadoop/0/dfs/data/, [DISK]file:/mnt/hadoop/1/dfs/data/, [DISK]file:/mnt/hadoop/2/dfs/data/]] heartbeating to /YYY:8020] DataNode - Block pool BP-879324367-YYY-1404837025894 (Datanode Uuid null) service to /YYY:8020 beginning handshake with NN 2014-11-27 17:06:36,167 INFO [DataNode: [[[DISK]file:/mnt/hadoop/0/dfs/data/, [DISK]file:/mnt/hadoop/1/dfs/data/, [DISK]file:/mnt/hadoop/2/dfs/data/]] heartbeating to /XXX:8020] DataNode - Block pool BP-879324367-YYY-1404837025894 (Datanode Uuid null) service to /XXX:8020 beginning handshake with NN 2014-11-27 17:06:36,185 INFO [DataNode: [[[DISK]file:/mnt/hadoop/0/dfs/data/, [DISK]file:/mnt/hadoop/1/dfs/data/, [DISK]file:/mnt/hadoop/2/dfs/data/]] heartbeating to /YYY:8020] DataNode - Block pool Block pool BP-879324367-YYY-1404837025894 (Datanode Uuid null) service to /YYY:8020 successfully registered with NN 2014-11-27 17:06:36,185 INFO [DataNode: [[[DISK]file:/mnt/hadoop/0/dfs/data/, [DISK]file:/mnt/hadoop/1/dfs/data/, [DISK]file:/mnt/hadoop/2/dfs/data/]] heartbeating to /XXX:8020] DataNode - Block pool Block pool BP-879324367-YYY-1404837025894 (Datanode Uuid null) service to /XXX:8020 successfully registered with NN 2014-11-27 17:06:36,186 INFO [DataNode: [[[DISK]file:/mnt/hadoop/0/dfs/data/, [DISK]file:/mnt/hadoop/1/dfs/data/, [DISK]file:/mnt/hadoop/2/dfs/data/]] heartbeating to /YYY:8020] DataNode - For namenode /YYY:8020 using DELETEREPORT_INTERVAL of 300000 msec BLOCKREPORT_INTERVAL of 21600000msec CACHEREPORT_INTERVAL of 10000msec Initial delay: 0msec; heartBeatInterval=3000 2014-11-27 17:06:36,186 INFO [DataNode: [[[DISK]file:/mnt/hadoop/0/dfs/data/, [DISK]file:/mnt/hadoop/1/dfs/data/, [DISK]file:/mnt/hadoop/2/dfs/data/]] heartbeating to /XXX:8020] DataNode - For namenode /XXX:8020 using DELETEREPORT_INTERVAL of 300000 msec BLOCKREPORT_INTERVAL of 21600000msec CACHEREPORT_INTERVAL of 10000msec Initial delay: 0msec; heartBeatInterval=3000 2014-11-27 17:06:36,264 INFO [DataNode: [[[DISK]file:/mnt/hadoop/0/dfs/data/, [DISK]file:/mnt/hadoop/1/dfs/data/, [DISK]file:/mnt/hadoop/2/dfs/data/]] heartbeating to /YYY:8020] DataNode - Namenode Block pool BP-879324367-YYY-1404837025894 (Datanode Uuid 91e8deeb-7030-4e7b-af14-a3f35cf65bd2) service to /YYY:8020 trying to claim ACTIVE state with txid=114828921 2014-11-27 17:06:36,265 INFO [DataNode: [[[DISK]file:/mnt/hadoop/0/dfs/data/, [DISK]file:/mnt/hadoop/1/dfs/data/, [DISK]file:/mnt/hadoop/2/dfs/data/]] heartbeating to /YYY:8020] DataNode - Acknowledging ACTIVE Namenode Block pool BP-879324367-YYY-1404837025894 (Datanode Uuid 91e8deeb-7030-4e7b-af14-a3f35cf65bd2) service to /YYY:8020 2014-11-27 17:06:36,511 INFO [DataNode: [[[DISK]file:/mnt/hadoop/0/dfs/data/, [DISK]file:/mnt/hadoop/1/dfs/data/, [DISK]file:/mnt/hadoop/2/dfs/data/]] heartbeating to /XXX:8020] DataNode - Sent 1 blockreports 49708 blocks total. Took 72 msec to generate and 174 msecs for RPC and NN processing. Got back commands none 2014-11-27 17:06:36,511 INFO [DataNode: [[[DISK]file:/mnt/hadoop/0/dfs/data/, [DISK]file:/mnt/hadoop/1/dfs/data/, [DISK]file:/mnt/hadoop/2/dfs/data/]] heartbeating to /YYY:8020] DataNode - Sent 1 blockreports 49708 blocks total. Took 76 msec to generate and 170 msecs for RPC and NN processing. Got back commands org.apache.hadoop.hdfs.server.protocol.FinalizeCommand@464c42e6 2014-11-27 17:06:36,512 INFO [DataNode: [[[DISK]file:/mnt/hadoop/0/dfs/data/, [DISK]file:/mnt/hadoop/1/dfs/data/, [DISK]file:/mnt/hadoop/2/dfs/data/]] heartbeating to /YYY:8020] DataNode - Got finalize command for block pool BP-879324367-YYY-1404837025894 2014-11-27 17:06:36,519 INFO [DataNode: [[[DISK]file:/mnt/hadoop/0/dfs/data/, [DISK]file:/mnt/hadoop/1/dfs/data/, [DISK]file:/mnt/hadoop/2/dfs/data/]] heartbeating to /XXX:8020] GSet - Computing capacity for map BlockMap 2014-11-27 17:06:36,523 INFO [DataNode: [[[DISK]file:/mnt/hadoop/0/dfs/data/, [DISK]file:/mnt/hadoop/1/dfs/data/, [DISK]file:/mnt/hadoop/2/dfs/data/]] heartbeating to /XXX:8020] GSet - capacity = 2^20 = 1048576 entries 2014-11-27 17:06:36,520 INFO [DataNode: [[[DISK]file:/mnt/hadoop/0/dfs/data/, [DISK]file:/mnt/hadoop/1/dfs/data/, [DISK]file:/mnt/hadoop/2/dfs/data/]] heartbeating to /XXX:8020] GSet - VM type = 64-bit 2014-11-27 17:06:36,522 INFO [DataNode: [[[DISK]file:/mnt/hadoop/0/dfs/data/, [DISK]file:/mnt/hadoop/1/dfs/data/, [DISK]file:/mnt/hadoop/2/dfs/data/]] heartbeating to /XXX:8020] GSet - 0.5% max memory 1.9 GB = 9.9 MB 2014-11-27 17:06:36,524 INFO [DataNode: [[[DISK]file:/mnt/hadoop/0/dfs/data/, [DISK]file:/mnt/hadoop/1/dfs/data/, [DISK]file:/mnt/hadoop/2/dfs/data/]] heartbeating to /XXX:8020] BlockPoolSliceScanner - Periodic Block Verification Scanner initialized with interval 504 hours for block pool BP-879324367-YYY-1404837025894
But block is sitll reported with two replicas, one of those is assigned to datanode which hasn't it:
<block_info> <block_id>1083356878</block_id> <block_name>blk_1083356878</block_name> <file> <local_name>commons-lang-2.6.jar</local_name> <local_directory>/user/user/analysis</local_directory> <user_name>user</user_name> <group_name>supergroup</group_name> <is_directory>false</is_directory> <access_time>1417094143429</access_time> <is_under_construction>false</is_under_construction> <ds_quota>-1</ds_quota> <permission_status>user:supergroup:rw-r--r--</permission_status> <replication>2</replication> <disk_space_consumed>568440</disk_space_consumed> <preferred_block_size>134217728</preferred_block_size> </file> <replicas> <replica> <host_name>bad_node</host_name> <is_corrupt>false</is_corrupt> </replica> <replica> <host_name>good_node</host_name> <is_corrupt>false</is_corrupt> </replica> </replicas> </block_info>
fsck does not change the situation, ony the namenode restart force it to recognize that block replica as missing.
As a result it is required to restart namenode after each disk failure which is not very practical...
Attachments
Issue Links
- duplicates
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HDFS-7208 NN doesn't schedule replication when a DN storage fails
- Closed