[HBASE-19166] AsyncProtobufLogWriter persists ProtobufLogWriter as class name for backward compatibility

• Type: Bug
• Status: Resolved
• Priority: Blocker
• Resolution: Fixed
• Fix Version/s: 2.0.0-beta-2, 2.0.0
• Component/s: wal
• Hadoop Flags: Reviewed
• Release Note: For backward compatibility, AsyncProtobufLogWriter uses "ProtobufLogWriter" as writer class name and SecureAsyncProtobufLogWriter uses "SecureProtobufLogWriter" as writer class name.
• Assignee: Ted Yu
• Reporter: Ted Yu
• Created: 03/Nov/17 00:16
• Updated: 01/Aug/18 06:22
• Resolved: 21/Feb/18 21:14

Description

For hlog generated by 2.x, log splitting from hbase1 would result in:

1134720 2018-02-13 10:43:57,590 WARN  [RS_LOG_REPLAY_OPS-ve0530:16020-0] regionserver.SplitLogWorker: log splitting of WALs/ve0534.halxg.cloudera.com,16020,1518546984742-splitting/ve0534.halxg.cloudera.com%2C16020%2C1518546984742.meta.1518546993545.meta failed, returning error
1134721 java.io.IOException: Got unknown writer class: AsyncProtobufLogWriter
1134722   at org.apache.hadoop.hbase.regionserver.wal.ProtobufLogReader.initInternal(ProtobufLogReader.java:220)
1134723   at org.apache.hadoop.hbase.regionserver.wal.ProtobufLogReader.initReader(ProtobufLogReader.java:169)
1134724   at org.apache.hadoop.hbase.regionserver.wal.ReaderBase.init(ReaderBase.java:66)
1134725   at org.apache.hadoop.hbase.regionserver.wal.ProtobufLogReader.init(ProtobufLogReader.java:164)
1134726   at org.apache.hadoop.hbase.wal.WALFactory.createReader(WALFactory.java:303)
1134727   at org.apache.hadoop.hbase.wal.WALFactory.createReader(WALFactory.java:267)
1134728   at org.apache.hadoop.hbase.wal.WALSplitter.getReader(WALSplitter.java:853)
1134729   at org.apache.hadoop.hbase.wal.WALSplitter.getReader(WALSplitter.java:777)
1134730   at org.apache.hadoop.hbase.wal.WALSplitter.splitLogFile(WALSplitter.java:298)
1134731   at org.apache.hadoop.hbase.wal.WALSplitter.splitLogFile(WALSplitter.java:236)

AsyncProtobufLogWriter didn't change WAL format and hence can use ProtobufLogWriter as the persisted class name so that we avoid the above during rolling upgrade.

Issue Links

• is related to: HBASE-19997 [rolling upgrade] 1.x => 2.x