[HBASE-8207] Replication could have data loss when machine name contains hyphen "-"

• Type: Bug
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 0.94.6, 0.95.0
• Fix Version/s: 0.98.0, 0.94.7, 0.95.0
• Component/s: Replication
• Hadoop Flags: Reviewed
• Assignee: Jeffrey Zhong
• Reporter: Jeffrey Zhong
• Created: 28/Mar/13 00:17
• Updated: 05/Sep/13 02:36
• Resolved: 29/Mar/13 17:36

Description

In the recent test case TestReplication* failures, I'm finally able to find the cause(or one of causes) for its intermittent failures.

When a machine name contains "-", it breaks the function ReplicationSource.checkIfQueueRecovered. It causes the following issue:

deadRegionServers list is way off so that replication doesn't wait for log splitting finish for a wal file and move on to the next one(data loss)

You can see that replication use those weird paths constructed from deadRegionServers to check a file existence

2013-03-26 21:26:51,385 INFO  [ReplicationExecutor-0.replicationSource,2-ip-10-197-0-156.us-west-1.compute.internal,52170,1364333181125] regionserver.ReplicationSource(524): Possible location hdfs://localhost:52882/user/ec2-user/hbase/.logs/1.compute.internal,52170,1364333181125/ip-10-197-0-156.us-west-1.compute.internal%252C52170%252C1364333181125.1364333199540
2013-03-26 21:26:51,386 INFO  [ReplicationExecutor-0.replicationSource,2-ip-10-197-0-156.us-west-1.compute.internal,52170,1364333181125] regionserver.ReplicationSource(524): Possible location hdfs://localhost:52882/user/ec2-user/hbase/.logs/1.compute.internal,52170,1364333181125-splitting/ip-10-197-0-156.us-west-1.compute.internal%252C52170%252C1364333181125.1364333199540
2013-03-26 21:26:51,387 INFO  [ReplicationExecutor-0.replicationSource,2-ip-10-197-0-156.us-west-1.compute.internal,52170,1364333181125] regionserver.ReplicationSource(524): Possible location hdfs://localhost:52882/user/ec2-user/hbase/.logs/west/ip-10-197-0-156.us-west-1.compute.internal%252C52170%252C1364333181125.1364333199540
2013-03-26 21:26:51,389 INFO  [ReplicationExecutor-0.replicationSource,2-ip-10-197-0-156.us-west-1.compute.internal,52170,1364333181125] regionserver.ReplicationSource(524): Possible location hdfs://localhost:52882/user/ec2-user/hbase/.logs/west-splitting/ip-10-197-0-156.us-west-1.compute.internal%252C52170%252C1364333181125.1364333199540
2013-03-26 21:26:51,391 INFO  [ReplicationExecutor-0.replicationSource,2-ip-10-197-0-156.us-west-1.compute.internal,52170,1364333181125] regionserver.ReplicationSource(524): Possible location hdfs://localhost:52882/user/ec2-user/hbase/.logs/156.us/ip-10-197-0-156.us-west-1.compute.internal%252C52170%252C1364333181125.1364333199540
2013-03-26 21:26:51,394 INFO  [ReplicationExecutor-0.replicationSource,2-ip-10-197-0-156.us-west-1.compute.internal,52170,1364333181125] regionserver.ReplicationSource(524): Possible location hdfs://localhost:52882/user/ec2-user/hbase/.logs/156.us-splitting/ip-10-197-0-156.us-west-1.compute.internal%252C52170%252C1364333181125.1364333199540
2013-03-26 21:26:51,396 INFO  [ReplicationExecutor-0.replicationSource,2-ip-10-197-0-156.us-west-1.compute.internal,52170,1364333181125] regionserver.ReplicationSource(524): Possible location hdfs://localhost:52882/user/ec2-user/hbase/.logs/0/ip-10-197-0-156.us-west-1.compute.internal%252C52170%252C1364333181125.1364333199540
2013-03-26 21:26:51,398 INFO  [ReplicationExecutor-0.replicationSource,2-ip-10-197-0-156.us-west-1.compute.internal,52170,1364333181125] regionserver.ReplicationSource(524): Possible location hdfs://localhost:52882/user/ec2-user/hbase/.logs/0-splitting/ip-10-197-0-156.us-west-1.compute.internal%252C52170%252C1364333181125.1364333199540

This happened in the recent test failure in http://54.241.6.143/job/HBase-0.94/org.apache.hbase$hbase/21/testReport/junit/org.apache.hadoop.hbase.replication/TestReplicationQueueFailover/queueFailover/?auto_refresh=false

Search for

File does not exist: hdfs://localhost:52882/user/ec2-user/hbase/.oldlogs/ip-10-197-0-156.us-west-1.compute.internal%2C52170%2C1364333181125.1364333199540

After 10 times retries, replication source gave up and move on to the next file. Data loss happens.

Since lots of EC2 machine names contain "-" including our Jenkin servers, this is a high impact issue.

Issue Links

• duplicates: HBASE-8212 Introduce a new separator instead of hyphen('-') for renaming recovered queues' znodes