Re: [Info-Ingres] Mutex: DCB iidbdb

I've just read the help on fd_affinity...



Would a better default have been FILE?



I'm going to change my setting to FILE on one of the three installations
I have with p13001 and see what happens over the next week.



Marty



From: Martin Bowes
Sent: 28 August 2008 10:56
To: 'David Richard'
Subject: RE: [Info-Ingres] Mutex: DCB iidbdb



Hi Richard,



On the servers where I see this problem (all have patch 13001) the grep
shows THREAD.



On the servers with the prior patch level I used (12479) the grep has no
output.



Marty



From: David Richard [mailto:Richard.David-at-aah.co.uk]
Sent: 28 August 2008 10:44
To: martin.bowes-at-iua.org.uk
Subject: RE: [Info-Ingres] Mutex: DCB iidbdb
Importance: High



Hi Martin,
We're also experiencing an intermittent hang on a very similar platform
to yours. We're currently on Patch 13017 with one expected anytime...)

What do you get when you run the following shell command? :-
grep 'fd_affinity' $II_SYSTEM/ingres/files/config.dat
Best regards,
Richard

Richard David
Senior Database Administrator
Business Systems
AAH Pharmaceuticals
tel (direct): +44 (0)2476 432992
fax: +44 (0)2476 432333
mobile: +44 (0)7810 784690
email: richard.david-at-aah.co.uk

-----Original Message-----
From: info-ingres-bounces-at-kettleriverconsulting.com
[mailto:info-ingres-bounces-at-kettleriverconsulting.com
] On Behalf Of
Martin Bowes
Sent: 28 August 2008 10:09
To: Ingres and related product discussion forum
Subject: [Info-Ingres] Mutex: DCB iidbdb

Hi everyone,
I'm running II 9.1.1 (a64.lnx/103)NPTL + patch13001 on Red Hat
Enterprise Linux Server release 5 (Tikanga).
About once a week my servers freeze up and new connections stall in
Mutex: DCB iidbdb
This sucks big time.
I've checked on the Ingres Tech support site and there are three old
bugs listed against the Mutex but none of them seem relevant in this
case.

Can anyone shed some light on the details shown by show mutex?
I get...
show mutex 00002AAAB9806810
Mutex at 00002AAAB9806810: Name: DCB iidbdb, EXCL owner: (tid:
1080768832, pid: 8227)
Shared: 0 Collisions: 0 Hwm: 0
Excl: 15 Collisions: 13
The pid=8227 was the DBMS server pid.
Does the tid tell me anything?
Martin Bowes

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On Aug 28, 12:04 pm, "Martin Bowes"
wrote:
> I've just read the help on fd_affinity...
>
> Would a better default have been FILE?
>
> I'm going to change my setting to FILE on one of the three installations
> I have with p13001 and see what happens over the next week.
>
> Marty
>

Yes, in 9.1 it should be set to FILE, when not running on Solaris. (at
least for the moment)
Whether this is related to the hangings you have seen or not is
difficult to say - some more information is needed. Besides the show
mutex output, a "show all sessions formatted" in iimonitor and the
stacktraces of the dbms process(some Linuxes know the pstack command,
otherwise gdb can be used) would be useful (Usually we us use a script
to collect this type of information)

Kristoff

Hi Kristoff,

Michaely Dyer contacted me and asked me to persevere with the THREAD
setting and run an 'inglogs' script the next time it Mutexes.

Marty

-----Original Message-----
From: info-ingres-bounces-at-kettleriverconsulting.com
[mailto:info-ingres-bounces-at-kettleriverconsulting.com] On Behalf Of
kristoff.picard-at-ingres.com
Sent: 29 August 2008 08:08
To: info-ingres-at-kettleriverconsulting.com
Subject: Re: [Info-Ingres] Mutex: DCB iidbdb

On Aug 28, 12:04 pm, "Martin Bowes"
wrote:
> I've just read the help on fd_affinity...
>
> Would a better default have been FILE?
>
> I'm going to change my setting to FILE on one of the three
installations
> I have with p13001 and see what happens over the next week.
>
> Marty
>

Yes, in 9.1 it should be set to FILE, when not running on Solaris. (at
least for the moment)
Whether this is related to the hangings you have seen or not is
difficult to say - some more information is needed. Besides the show
mutex output, a "show all sessions formatted" in iimonitor and the
stacktraces of the dbms process(some Linuxes know the pstack command,
otherwise gdb can be used) would be useful (Usually we us use a script
to collect this type of information)

Kristoff
_______________________________________________
Info-Ingres mailing list
Info-Ingres-at-kettleriverconsulting.com
http://www.kettleriverconsulting.com...fo/info-ingres

Hi Marty,
be sure to use the latest version of inglogs(1.22, but 1.23 is coming
soon ...), which is able to collect the stacktraces of the Ingres
processes even on Linux.
It makes use from the pstack command, which isn't available on all
Linux versions. If it's not available in your installation you can
call "inglogs +stackdebug", which uses gdb to get the stacktraces.

Cheers
Kristoff

Hi Kristoff,

I'm running with 1.22.

The host I'll run on has a pstack command so 1.23 should be cool as
well.

Marty



-----Original Message-----
From: info-ingres-bounces-at-kettleriverconsulting.com
[mailto:info-ingres-bounces-at-kettleriverconsulting.com] On Behalf Of
Kristoff
Sent: 01 September 2008 16:43
To: info-ingres-at-kettleriverconsulting.com
Subject: Re: [Info-Ingres] Mutex: DCB iidbdb

Hi Marty,
be sure to use the latest version of inglogs(1.22, but 1.23 is coming
soon ...), which is able to collect the stacktraces of the Ingres
processes even on Linux.
It makes use from the pstack command, which isn't available on all
Linux versions. If it's not available in your installation you can
call "inglogs +stackdebug", which uses gdb to get the stacktraces.

Cheers
Kristoff
_______________________________________________
Info-Ingres mailing list
Info-Ingres-at-kettleriverconsulting.com
http://www.kettleriverconsulting.com...fo/info-ingres