[HBASE-13832] Procedure V2: master fail to start due to WALProcedureStore sync failures when HDFS data nodes count is low

• Type: Sub-task
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 1.1.0, 1.2.0, 2.0.0
• Fix Version/s: 1.2.0, 1.1.2, 1.3.0, 2.0.0
• Component/s: master, proc-v2
• Assignee: Matteo Bertozzi
• Reporter: Stephen Yuan Jiang
• Created: 03/Jun/15 21:40
• Updated: 17/Jun/22 18:15
• Resolved: 09/Jul/15 17:58

Description

when the data node < 3, we got failure in WALProcedureStore#syncLoop() during master start. The failure prevents master to get started.

2015-05-29 13:27:16,625 ERROR [WALProcedureStoreSyncThread] wal.WALProcedureStore: Sync slot failed, abort.
java.io.IOException: Failed to replace a bad datanode on the existing pipeline due to no more good datanodes being available to try. (Nodes: current=[DatanodeInfoWithStorage[10.333.444.555:50010,DS-3c7777ed-93f4-47b6-9c23-1426f7a6acdc,DISK], DatanodeInfoWithStorage[10.222.666.777:50010,DS-f9c983b4-1f10-4d5e-8983-490ece56c772,DISK]],                     original=[DatanodeInfoWithStorage[10.333.444.555:50010,DS-3c7777ed-93f4-47b6-9c23-1426f7a6acdc,DISK], DatanodeInfoWithStorage[10.222.666.777:50010,DS-f9c983b4-1f10-4d5e-8983-    490ece56c772,DISK]]). The current failed datanode replacement policy is DEFAULT, and a client may configure this via 'dfs.client.block.write.replace-datanode-on-failure.policy'  in its configuration.
  at org.apache.hadoop.hdfs.DFSOutputStream$DataStreamer.findNewDatanode(DFSOutputStream.java:951)

One proposal is to implement some similar logic as FSHLog: if IOException is thrown during syncLoop in WALProcedureStore#start(), instead of immediate abort, we could try to roll the log and see whether this resolve the issue; if the new log cannot be created or more exception from rolling the log, we then abort.