Re: [HACKERS] WARNING : pgstat wait timeout - Postgres 9.1

2013-05-24 Thread Mathieu Guerin
Hello,

Thanks a lot for your answers.

 You should get it...
 stats_temp_directory   |
pg_stat_tmp   | Writes temporary
statistics files to the specified directory.

I don't know why i don't get it. I am in 9.1 version...

Moreover, when I mount pg_stat_tmp in a tmpfs, the warning messages
decrease  the warning messages decrease from 1 each minutes to 1 each five
secondes. I don't have any others logs warning but the file pg_stat.stat in
the mounting point is not created... I tryed before on a test environment
and it works...

If you have any ideas...
Thanks a lot.
Regards,
Math



2013/5/24 Michael Paquier michael.paqu...@gmail.com




 On Thu, May 23, 2013 at 9:31 PM, Mathieu Guerin 
 mathieu.gueri...@gmail.com wrote:

 What are the consequences ? Because this file will be remove if the
 server reboot.

 Those temporary statistics are stored in global directory when server
 shuts down, so the risk here would be to lose a portion of this data in the
 case of a crash, either at PG or at OS level.


 If we change the parameter stats_temp_directory is it necessary to
 reboot the server ?

 No, sending SIGHUP to the server is enough.


 When I lauch a SHOW ALL; command, the parameter stats_temp_director is
 not here.

 You should get it...
 stats_temp_directory|
 pg_stat_tmp   | Writes temporary
 statistics files to the specified directory.
  --
 Michael



Re: [HACKERS] WARNING : pgstat wait timeout - Postgres 9.1

2013-05-24 Thread Mathieu Guerin
About the stats_temp_directory, I didn't run as root...
Now I'm sure the configurations are correct.

I think, I have too much IO to use stats. I will ever have this message...
Maybe I can disable this option.
Do you know what it really impact ?

Thanks.
Math




2013/5/24 Mathieu Guerin mathieu.gueri...@gmail.com

 Hello,

 Thanks a lot for your answers.


  You should get it...
  stats_temp_directory   |
 pg_stat_tmp   | Writes temporary
 statistics files to the specified directory.

 I don't know why i don't get it. I am in 9.1 version...

 Moreover, when I mount pg_stat_tmp in a tmpfs, the warning messages
 decrease  the warning messages decrease from 1 each minutes to 1 each five
 secondes. I don't have any others logs warning but the file pg_stat.stat in
 the mounting point is not created... I tryed before on a test environment
 and it works...

 If you have any ideas...
 Thanks a lot.
 Regards,
 Math



 2013/5/24 Michael Paquier michael.paqu...@gmail.com




 On Thu, May 23, 2013 at 9:31 PM, Mathieu Guerin 
 mathieu.gueri...@gmail.com wrote:

 What are the consequences ? Because this file will be remove if the
 server reboot.

 Those temporary statistics are stored in global directory when server
 shuts down, so the risk here would be to lose a portion of this data in the
 case of a crash, either at PG or at OS level.


 If we change the parameter stats_temp_directory is it necessary to
 reboot the server ?

 No, sending SIGHUP to the server is enough.


 When I lauch a SHOW ALL; command, the parameter stats_temp_director is
 not here.

 You should get it...
 stats_temp_directory|
 pg_stat_tmp   | Writes temporary
 statistics files to the specified directory.
  --
 Michael





Re: [HACKERS] WARNING : pgstat wait timeout - stats_temp_directory - postgres 9.1

2013-05-23 Thread Alvaro Herrera
Mathieu Guerin escribió:
 Hello,
 
 I am facing a problem with pgstat as my subject says. I known, some topics
 are open about that, but I would like to go deeper.
 
 Some person told that the better way to don't have this message anymore is
 to configure pgstat.stat to be loaded in the RAM with a tmpfs mount point.
 
 What are the consequences ? Because this file will be remove if the server
 reboot.

There are two separate files, one is the temp file which is used while
the server is running and is written very frequently.  You put that one
on volatile storage (stats_temp_directory) and immediately see a
performance benefit.

The other one is the permanent file, which is written only once when the
system is shutting down.  This is not put in stats_temp_directory, so
it's safe.

In case of a crash (the server didn't have the chance to write the
permanent file), stats would be reset anyway at restart, so there's no
conceptual problem with the permanent file not being written.

 If we change the parameter stats_temp_directory is it necessary to reboot
 the server ?

No, a reload (pg_ctl reload) is sufficient.

-- 
Álvaro Herrerahttp://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training  Services


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Re: [HACKERS] WARNING : pgstat wait timeout - Postgres 9.1

2013-05-23 Thread Michael Paquier
On Thu, May 23, 2013 at 9:31 PM, Mathieu Guerin
mathieu.gueri...@gmail.comwrote:

 What are the consequences ? Because this file will be remove if the server
 reboot.

Those temporary statistics are stored in global directory when server shuts
down, so the risk here would be to lose a portion of this data in the case
of a crash, either at PG or at OS level.


 If we change the parameter stats_temp_directory is it necessary to reboot
 the server ?

No, sending SIGHUP to the server is enough.


 When I lauch a SHOW ALL; command, the parameter stats_temp_director is
 not here.

You should get it...
stats_temp_directory|
pg_stat_tmp   | Writes temporary
statistics files to the specified directory.
-- 
Michael


Re: [HACKERS] WARNING: pgstat wait timeout

2010-01-29 Thread Magnus Hagander
2010/1/29 Greg Smith g...@2ndquadrant.com:
 I just found a few of these errors in a log file during some pgbench testing 
 tonight.  Linux, recent CVS HEAD; given the range of systems and versions 
 this has been reported against now, this bug doesn't look like a platform or 
 version/build specific issue.

 Unfortunately the instance I had up wasn't setup very well for logging, but I 
 did notice that all of the ones I saw had nearby messages about autovacuum 
 issues, which seems to match Tom's earlier suggestion at 
 http://archives.postgresql.org/pgsql-bugs/2009-07/msg00083.php that the 
 source of the warning (but not necessarily the underlying problem) for these 
 is the autovacuum launcher complaining; here's two different sets:

 ERROR:  canceling autovacuum task
 CONTEXT:  automatic analyze of table pgbench.public.pgbench_accounts
 WARNING:  pgstat wait timeout
 WARNING:  pgstat wait timeout
 ERROR:  canceling autovacuum task
 CONTEXT:  automatic analyze of table pgbench.public.pgbench_accounts

 WARNING:  pgstat wait timeout
 ERROR:  canceling autovacuum task
 CONTEXT:  automatic analyze of table pgbench.public.pgbench_accounts
 ERROR:  canceling autovacuum task
 CONTEXT:  automatic analyze of table pgbench.public.pgbench_accounts

 Because of what I'm (not) seeing in pg_stat_bgwriter, I'm suspicious that its 
 underlying work or messages may be involved here.  I'm not seeing the sort of 
 totals I expect in that view after these large bouts of activity.  Now, my 
 use tonight has included the new pg_stat_reset_shared('bgwriter') to clear 
 out those stats between runs, so perhaps that's involved too.  Guessing not 
 only because of the reports going back to 8.4 that also have this error 
 message.

 Will keep an eye out for this one now that I know I might run into it, have 
 already cranked up the logging and will look for something reproducible to 
 gather more info.

I've seen this happen semi-frequently during initdb on win32 on an
Amazon EC2 image. I attributed it to the combination of windows and
overloaded virtualization, but it may just be that it shows up more
often there.

-- 
 Magnus Hagander
 Me: http://www.hagander.net/
 Work: http://www.redpill-linpro.com/

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Re: [HACKERS] WARNING: pgstat wait timeout

2010-01-28 Thread Greg Smith
I just found a few of these errors in a log file during some pgbench 
testing tonight.  Linux, recent CVS HEAD; given the range of systems and 
versions this has been reported against now, this bug doesn't look like 
a platform or version/build specific issue.


Unfortunately the instance I had up wasn't setup very well for logging, 
but I did notice that all of the ones I saw had nearby messages about 
autovacuum issues, which seems to match Tom's earlier suggestion at 
http://archives.postgresql.org/pgsql-bugs/2009-07/msg00083.php that the 
source of the warning (but not necessarily the underlying problem) for 
these is the autovacuum launcher complaining; here's two different sets:


ERROR:  canceling autovacuum task
CONTEXT:  automatic analyze of table pgbench.public.pgbench_accounts
WARNING:  pgstat wait timeout
WARNING:  pgstat wait timeout
ERROR:  canceling autovacuum task
CONTEXT:  automatic analyze of table pgbench.public.pgbench_accounts

WARNING:  pgstat wait timeout
ERROR:  canceling autovacuum task
CONTEXT:  automatic analyze of table pgbench.public.pgbench_accounts
ERROR:  canceling autovacuum task
CONTEXT:  automatic analyze of table pgbench.public.pgbench_accounts

Because of what I'm (not) seeing in pg_stat_bgwriter, I'm suspicious 
that its underlying work or messages may be involved here.  I'm not 
seeing the sort of totals I expect in that view after these large bouts 
of activity.  Now, my use tonight has included the new 
pg_stat_reset_shared('bgwriter') to clear out those stats between runs, 
so perhaps that's involved too.  Guessing not only because of the 
reports going back to 8.4 that also have this error message.


Will keep an eye out for this one now that I know I might run into it, 
have already cranked up the logging and will look for something 
reproducible to gather more info.


--
Greg Smith2ndQuadrant   Baltimore, MD
PostgreSQL Training, Services and Support
g...@2ndquadrant.com  www.2ndQuadrant.com


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Re: [HACKERS] WARNING: pgstat wait timeout

2010-01-21 Thread Matteo Beccati

Il 21/01/2010 03:33, Jaime Casanova ha scritto:

On Wed, Jan 20, 2010 at 9:32 PM, Jaime Casanova
jcasa...@systemguards.com.ec  wrote:

On Wed, Jan 20, 2010 at 6:20 PM, Sergey E. Koposovm...@sai.msu.ru  wrote:

Hello hackers,

I've recently hit the message WARNING:  pgstat wait timeout with PG 8.4.2.


i see the same yesterday when initdb a freshly compiled 8.5dev +
lock_timeout patch
i thought maybe it was related to that patch and was thinking in
recompile without the patch but hadn't time, obviously i was wrong



ah! i forgot to say that it was on win32 + mingw, to confirme that
patch works fin in that os


I've seen it a few days ago with 8.5alpha3 on NetBSD when I left the 
backend running for a few days. Backend was completely inactive but the 
massage was repeated 3-4 times. Googling didn't help and I didnt' know 
how to replicate it.



Cheers
--
Matteo Beccati

Development  Consulting - http://www.beccati.com/

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Re: [HACKERS] WARNING: pgstat wait timeout

2010-01-20 Thread Jaime Casanova
On Wed, Jan 20, 2010 at 6:20 PM, Sergey E. Koposov m...@sai.msu.ru wrote:
 Hello hackers,

 I've recently hit the message WARNING:  pgstat wait timeout with PG 8.4.2.

i see the same yesterday when initdb a freshly compiled 8.5dev +
lock_timeout patch
i thought maybe it was related to that patch and was thinking in
recompile without the patch but hadn't time, obviously i was wrong

-- 
Atentamente,
Jaime Casanova
Soporte y capacitación de PostgreSQL
Asesoría y desarrollo de sistemas
Guayaquil - Ecuador
Cel. +59387171157

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Re: [HACKERS] WARNING: pgstat wait timeout

2010-01-20 Thread Jaime Casanova
On Wed, Jan 20, 2010 at 9:32 PM, Jaime Casanova
jcasa...@systemguards.com.ec wrote:
 On Wed, Jan 20, 2010 at 6:20 PM, Sergey E. Koposov m...@sai.msu.ru wrote:
 Hello hackers,

 I've recently hit the message WARNING:  pgstat wait timeout with PG 8.4.2.

 i see the same yesterday when initdb a freshly compiled 8.5dev +
 lock_timeout patch
 i thought maybe it was related to that patch and was thinking in
 recompile without the patch but hadn't time, obviously i was wrong


ah! i forgot to say that it was on win32 + mingw, to confirme that
patch works fin in that os

-- 
Atentamente,
Jaime Casanova
Soporte y capacitación de PostgreSQL
Asesoría y desarrollo de sistemas
Guayaquil - Ecuador
Cel. +59387171157

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