[Swift-user] Swift running errors

[Ioan Raicu]

I doubt its a bug in the JVM, its probably the application not closing 
all the file/stream handles.   For example, I ran into this problem when 
I was using:
> Process child = Runtime.getRuntime().exec(command);
but not consuming and closing the stdout and stderr streams which get 
created automatically when the child process gets created.  Simply 
setting child to null after the process exited did not close the 
streams.  This quickly lead to too many open file handles after a few 
hundred exec() calls.  I had to make a wrapper class of the Process 
class that took care of consuming and closing the output streams by 
default, and my problems went away.

Just another idea of where to look for potential problems in the code.

Ioan

Mihael Hategan wrote:
>>> 2. When runing a workflow which involves 1000nodes, I 
>>> encounter the following errors very frequently, but not all 
>>> the time:
>>>       
>> [..]
>>     
>>>         java.io.IOException: Too many open files
>>>       
>> What machine are you running on? Have you changed any configuration 
>> parameters? A basic 1000 job workflow should run fine with the default 
>> settings.
>>
>> On the machine you are running on, type   ulimit -a   and paste that here.
>>
>>     
>
> There is some odd bug in the JVM. Some, and I don't remember exactly
> which, classes related to time/date open time zone resource files
> repeatedly and they forget to close them. If this is done fast enough
> (faster than the garbage collector reaches those files which get closed
> when finalized), you get this error.
>
> It might be something else though.
>
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>
>   

-- 
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Ioan Raicu
Ph.D. Candidate
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Distributed Systems Laboratory
Computer Science Department
University of Chicago
1100 E. 58th Street, Ryerson Hall
Chicago, IL 60637
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Email: iraicu at cs.uchicago.edu
Web:   http://www.cs.uchicago.edu/~iraicu
http://dev.globus.org/wiki/Incubator/Falkon
http://www.ci.uchicago.edu/wiki/bin/view/VDS/DslCS
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