[HDFS-6448] BlockReaderLocalLegacy should set socket timeout based on conf.socketTimeout

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.4.0, 3.0.0-alpha1
• Fix Version/s: 2.5.0
• Component/s: hdfs-client
• Target Version/s: 2.5.0
• Assignee: Liang Xie
• Reporter: Liang Xie
• Created: 26/May/14 06:36
• Updated: 12/May/16 18:14
• Resolved: 28/May/14 17:44

Description

Our hbase deployed upon hadoop2.0, in one accident, we hit HDFS-5016 in HDFS side, but we also found from HBase side, the dfs client was hung at getBlockReader, after reading code, we found there is a timeout setting in current codebase though, but the default hdfsTimeout value is "-1" ( from Client.java:getTimeout(conf) )which means no timeout...

The hung stack trace like following:
at $Proxy21.getBlockLocalPathInfo(Unknown Source)
at org.apache.hadoop.hdfs.protocolPB.ClientDatanodeProtocolTranslatorPB.getBlockLocalPathInfo(ClientDatanodeProtocolTranslatorPB.java:215)
at org.apache.hadoop.hdfs.BlockReaderLocal.getBlockPathInfo(BlockReaderLocal.java:267)
at org.apache.hadoop.hdfs.BlockReaderLocal.newBlockReader(BlockReaderLocal.java:180)
at org.apache.hadoop.hdfs.DFSClient.getLocalBlockReader(DFSClient.java:812)

One feasible fix is replacing the hdfsTimeout with socketTimeout. see attached patch. Most of credit should give Shaohui Liu