[ http://issues.apache.org/jira/browse/HADOOP-286?page=comments#action_12422012 ] Konstantin Shvachko commented on HADOOP-286: --------------------------------------------
It looks like the following scenario leads to this exception. LEASE_PERIOD = 60 sec is a global constants defining for how long a lease is issued. DFSClient.LeaseChecker renews this client leases every 30 sec = LEASE_PERIOD/2. If the renewLease() fails then the client retries to renew every second. One of the most popular reasons the renewLease() fails is because it timeouts SocketTimeoutException. This happens when the namenode is busy, which is not unusual since we lock it for each operation. The socket timeout is defined by the config parameter "ipc.client.timeout", which is set to 60 sec in hadoop-default.xml That means that the renewLease() can last up to 60 seconds and the lease will expire the next time the client tries to renew it, which could be up to 90 seconds after the lease was created or renewed last time. So there are 2 simple solutions to the problem: 1) to increase LEASE_PERIOD 2) to decrease ipc.client.timeout A related problem is that DFSClient sends lease renew requests no matter what every 30 seconds or less. It looks like the DFSClient has enough information to send renew messages only if it really holds a lease. A simple solution would be avoid calling renewLease() when DFSClient.pendingCreates is empty. This could substantially decrease overall net traffic for map/reduce. > copyFromLocal throws LeaseExpiredException > ------------------------------------------ > > Key: HADOOP-286 > URL: http://issues.apache.org/jira/browse/HADOOP-286 > Project: Hadoop > Issue Type: Bug > Components: dfs > Affects Versions: 0.3.0 > Environment: redhar linux > Reporter: Runping Qi > > Loading local files to dfs through hadoop dfs -copyFromLocal failed due to > the following exception: > copyFromLocal: org.apache.hadoop.dfs.LeaseExpiredException: No lease on > output_crawled.1.txt > at > org.apache.hadoop.dfs.FSNamesystem.getAdditionalBlock(FSNamesystem.java:414) > at org.apache.hadoop.dfs.NameNode.addBlock(NameNode.java:190) > at sun.reflect.GeneratedMethodAccessor9.invoke(Unknown Source) > at > sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) > at java.lang.reflect.Method.invoke(Method.java:585) > at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:243) > at org.apache.hadoop.ipc.Server$Handler.run(Server.java:231) -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://issues.apache.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira
