[Swift-devel] Coaster socket issue

[Jonathan Monette]

What is the open files limit on that machine(ulimit -n)?  I have never witnessed this issue before so it may only appear on machines with relatively low open file limits(raven has 1K but beagle has 60K).  This is still something we should look into though.

On Mar 28, 2012, at 8:49 PM, David Kelly wrote:

> 
> Strange, I just ran into a similar issues tonight while running on ibicluster (SGE). I saw the "too many open files" error after sitting in the queue waiting for a job to start. I restarted the job and then periodically ran 'lsof' to see the number of java pipes increasing over time. I thought at first this might be SGE specific, but perhaps it is something else. (This was with 0.93)
> 
> ----- Original Message -----
>> From: "Jonathan Monette" <jonmon at mcs.anl.gov>
>> To: "swift-devel at ci.uchicago.edu Devel" <swift-devel at ci.uchicago.edu>
>> Sent: Wednesday, March 28, 2012 8:30:52 PM
>> Subject: [Swift-devel] Coaster socket issue
>> Hello,
>> In running the SciColSim app on raven(which is a cluster similar to
>> Beagle) I noticed that the app hung. It was not hung where the hang
>> checker kicked in but Swift was waiting for jobs to be active but
>> there was none submitted to PBS. I took a look at the log file and
>> noticed that I had a java.io.IOException thrown for "too many open
>> files". Since I killed it I couldn't probe the run but I had the same
>> run running on Beagle. Upon Mike's suggestion I took a look at the
>> /proc/<pid>/fd directory. There were over 2000 sockets in the
>> CLOSE_WAIT state with a single message in the receive queue. Raven has
>> a limit of 1024 open files at a time while Beagle has a limit around
>> 60K number of files open. I got this limit using ulimit -n.
>> 
>> So my question is, why is there so many sockets waiting to be closed?
>> I did some reading about the CLOSE_WAIT state and it seems this
>> happens when one of the ends closes there socket but the other does
>> not. Is Coaster not closing the socket when a worker shuts down? What
>> other information should I be looking for to help debug the issue.
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