[gram-user] Re: [gram-dev] Response time anomalies during job submissions with delegation

[Stuart Martin]

Hi Peter,

Thank you very much for the investigation and analysis on this.  I  
created a bug entry based on your findings.

http://bugzilla.globus.org/globus/show_bug.cgi?id=4452

Best Regards,
Stu

On May 26, 2006, at 8:59 AM, Peter Gardfjäll wrote:

>
> Apparently Java does not mandate any scheduling order for threads  
> waiting
> for monitor entrance. Hence, this order may vary between different JVM
> implementations and operating systems.
>
> http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6316090
>
> In my environment, Java 1.5 queues up threads waiting for monitor  
> entrance
> in stack-order, which makes the implementation starvation-prone (if a
> steady stream of threads are attempting to enter the monitor, the  
> first
> waiting thread will never be granted monitor entry and will hence be
> starved out). In Java 1.4, however, threads seem to be queued in  
> ("fair")
> FIFO-order.
>
> Consequently I restarted my container with Java 1.4 and I haven't  
> (yet :)
> observed any of the abnormal response times seen previously.
>
> As a work-around Sun recommends the use of 'one of the excellent
> "fair" lock constructs in java.util.concurrent.'
>
> Maybe this approach should be taken by Globus developers in the future
> since the synchronized construct, apparently, cannot be relied upon.
>
> regards, Peter
>
>