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From Emmanuel Lecharny <>
Subject Re: Performance issues and strange logs
Date Thu, 13 Oct 2011 15:49:25 GMT
On 10/13/11 5:31 PM, Craig Setera wrote:
> Assuming that the errors and warnings are not a big deal, can you suggest
> any reasons that we would have connections stacking up and timing out?  The
> use case is likely heavier on write than would be standard for LDAP, but it
> seems the failure threshold (number of connections) is very low.  This is
> hosted on a multi-core machine (virtual machine) and when it gets bad, our
> operations people say that a single core of the machine is pegged at 100%
> CPU while others are essentially idle.  Are there parts of Apache DS that
> have thread affinity and would be "stuck" to a single processor?
Ok, 1.5.5 is pretty old, and depends on MINA-2.0.0-M6. This version of 
the NIO framework sometime gets stuck with 100% CPU (it's a JVM bug) 
when some session are closed just after having been opened (basically, 
the selector loop get crazy and eats 100% CPU looping).

It might be the reason why you see this 100% CPU for some sessions (as 
we have one selector per CPU, the other sessions might be ok).

I would suggest you switch to at least 1.5.7, but even better to 2.0.0-M3.

Emmanuel L├ęcharny

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