Re: CPU Usage in running process on HP-UX 11.31
- From: Tanel Poder <tanel@xxxxxxxxxx>
- To: knecht.stefan@xxxxxxxxx
- Date: Tue, 8 Sep 2009 20:09:41 +0800
You need to do stack profiling on your dispatcher process for understanding
in which Oracle functions most of time is spent. Then you can send the top
stacks to Oracle support and they can search their internal knowledge bases
based on that.
You can use pstack for getting a bunch of stack traces and aggregate them
with an awk script or use HP's Caliper tool for doing the call graph
aggregation for you.
This all is of course if you have narrowed the issue down to dispatcher (and
dispatcher only), otherwise regular Oracle troubleshooting techniques should
be used first.
Tanel.
On Tue, Sep 8, 2009 at 4:48 PM, Stefan Knecht <knecht.stefan@xxxxxxxxx>wrote:
> Ciao Martin
>
>
> On Tue, Sep 8, 2009 at 10:17 AM, Martin Berger
> <martin.a.berger@xxxxxxxxx>wrote:
>
>> Hi Stefan,
>> so I'm prety sure you know these 2 ML-notes:
>> Subject: *Multi-Threaded Server (MTS) Trace Events* Doc
>> ID<https://metalink2.oracle.com/help/usaeng/Search/search.html#file>:
>> *106624.1*
>> *Subject: MTS: How to Debug a Hanging Multi-Threaded Server Connection Doc
>> ID <https://metalink2.oracle.com/help/usaeng/Search/search.html#file>:
>> 106621.1*
>>
>>
> Yep, I'm aware of those. Unfortunately they don't ehlp in this case.
>
>
>> If a tusc trace did not give any hints, the next step would be attaching a
>> debugger to the process. But this is of realy limited use; even if you know
>> which CPU-commands it's using all the time, of which loops are spinning, you
>> can hardly find the reason without the source-code and debug-hooks prepared
>> in the binary.
>>
>> Yes, problem is that even tusc slows down the process quite massively. And
> since we only experience the issue in production, we can't really use any
> even more intrusive tools. I was merely hoping HP-UX provides some new hooks
> in the release 3 kernel that are not yet widely known, that allow for
> measurign those things (analogous to i.e. dtrace on sun).
>
> Just some tries to get a lucky hit:
>> As users has not changed, has anything else changed?
>>
>
> Nope, not that I'm aware of, nor did the apps guys claim any changes
>
>
>> OS-patched?
>>
> Nope
>
>
>> network subsystem? (new switches, now network card new drivers, new team?)
>>
> Nope
>
>
>> io-subsystem?
>>
> Some new disks were added to ASM. However, we don't experience any storage
> issues.
>
>
>> clients?
>>
> Nope
>
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