Re: hedged read bug

2014-06-09 Thread lei liu
Hi Chirs, I write one test case base on HDFS-6231 patch. You are right, no future is canceled. But I find the while loop in hedgedFetchBlockByteRange method execute 30,000 times. Please see hedged-read-test-case.patch in HDFS-6494 jira. I think that may be one problem. 2014-06-10 4:46 GMT+08:00

Re: hedged read bug

2014-06-09 Thread Ted Yu
Lei: If you can attach the test code from your first email to HDFS-6494, that would help us know the scenario you were referring to. Cheers On Mon, Jun 9, 2014 at 12:06 PM, Chris Nauroth wrote: > Hi Lei, > > I just reviewed this code path on trunk again, and I couldn't find a > problem. It ap

Re: hedged read bug

2014-06-09 Thread Chris Nauroth
Hi Lei, I just reviewed this code path on trunk again, and I couldn't find a problem. It appears to me that if one future fails, then the exception handling logic will allow the other future to proceed without canceling. Also, I haven't been able to reproduce the infinite loop that you reported

Re: hedged read bug

2014-06-08 Thread lei liu
Hi Chris, I review the patch, I think there is problem in the patch. Example there are two futures, if the first return futrue is failure and then the the second future will be cancled. 2014-06-07 3:44 GMT+08:00 Chris Nauroth : > Hello Lei, > > There is a known bug in 2.4.0 that can cause he

Re: hedged read bug

2014-06-06 Thread Chris Nauroth
Hello Lei, There is a known bug in 2.4.0 that can cause hedged reads to hang. I fixed it in HDFS-6231: https://issues.apache.org/jira/browse/HDFS-6231 This patch will be included in the forthcoming 2.4.1 release. I'm curious to see if applying this patch fixes the problem for you. Can you try