HDFS-1148 - Andy From: Gokulakannan M <gok...@huawei.com> Subject: RE: Lots of Different Kind of Datanode Errors To: hdfs-user@hadoop.apache.org, apurt...@apache.org Date: Monday, June 7, 2010, 10:31 PM
Hi Andy, What is the reference of that fix? Thanks, Gokul From: Andrew Purtell [mailto:apurt...@apache.org] Sent: Tuesday, June 08, 2010 1:24 AM To: hdfs-user@hadoop.apache.org Subject: Re: Lots of Different Kind of Datanode Errors Current synchronization on FSDataset seems not quite right. Doing what amounted to applying Todd's patch that modifies FSDataSet to use reentrant rwlocks cleared up that type of problem for us. - Andy From: Jeff Whiting <je...@qualtrics.com> Subject: Re: Lots of Different Kind of Datanode Errors To: hdfs-user@hadoop.apache.org Date: Monday, June 7, 2010, 10:02 AM Thanks for the replies. I have turned off swap on all the machines to prevent any swap problems. I was pounding my hard drives quite hard. I had a simulated 60 clients loading data as fast as I could into hbase with a map reduce export job going at the same time. Would that scenario explain some of the errors I was seeing? Over the weekend under more of a normal load I haven't not any exception except for about 6 of these: 2010-06-05 03:46:41,229 ERROR datanode.DataNode (DataXceiver.java:run(131)) - DatanodeRegistration(192.168.0.98:50010, storageID=DS-1806250311-192.168.0.98-50010-1274208294562, infoPort=50075, ipcPort=50020):DataXceiver org.apache.hadoop.hdfs.server.datanode.BlockAlreadyExistsException: Block blk_-1677111232590888964_4471547 is valid, and cannot be written to. at org.apache.hadoop.hdfs.server.datanode.FSDataset.writeToBlock(FSDataset.java:999) The reason the config shows 4096 is because I increased the xceiver account after the first email message in this thread. ~Jeff Allen Wittenauer wrote: On Jun 4, 2010, at 12:03 PM, Todd Lipcon wrote: Hi Jeff, That seems like a reasonable config, but the error message you pasted indicated xceivers was set to 2048 instead of 4096. Also, in my experience SocketTimeoutExceptions are usually due to swapping. Verify that your machines aren't swapping when you're under load. Or doing any other heavy disk IO. -- Jeff WhitingQualtrics Senior Software engineerje...@qualtrics.com
