Re: PostgreSQL strugling during high load

От: Cosimo Streppone
Тема: Re: PostgreSQL strugling during high load
Дата: ,
Msg-id: 4284C661.4050406@streppone.it
(см: обсуждение, исходный текст)
Ответ на: Re: PostgreSQL strugling during high load  ("Mindaugas Riauba")
Список: pgsql-performance

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PostgreSQL strugling during high load  ("Mindaugas Riauba", )
 Re: PostgreSQL strugling during high load  ("Steinar H. Gunderson", )
 Re: PostgreSQL strugling during high load  (Tom Lane, )
  Re: PostgreSQL strugling during high load  (Mischa Sandberg, )
 Re: PostgreSQL strugling during high load  ("Mindaugas Riauba", )
  Re: PostgreSQL strugling during high load  (Tom Lane, )
   Re: PostgreSQL strugling during high load  (Donald Courtney, )
  Re: PostgreSQL strugling during high load  (Cosimo Streppone, )
  Re: PostgreSQL strugling during high load  ("Matthew T. O'Connor", )
   Re: PostgreSQL strugling during high load  ("Thomas F. O'Connell", )
 Re: PostgreSQL strugling during high load  ("Mindaugas Riauba", )
  Re: PostgreSQL strugling during high load  ("Steinar H. Gunderson", )
 Re: PostgreSQL strugling during high load  ("Mindaugas Riauba", )
  Re: PostgreSQL strugling during high load  (Tom Lane, )
 Re: PostgreSQL strugling during high load  ("Mindaugas Riauba", )
 Re: PostgreSQL strugling during high load  ("Anjan Dave", )
  Re: PostgreSQL strugling during high load  (Donald Courtney, )
  Re: PostgreSQL strugling during high load  (Vivek Khera, )
  Re: PostgreSQL strugling during high load  (Josh Berkus, )
   Re: PostgreSQL strugling during high load  (Steve Poe, )
 Re: PostgreSQL strugling during high load  ("Anjan Dave", )

Mindaugas Riauba wrote:

>>The "vacuum cost" parameters can be adjusted to make vacuums fired
>>by pg_autovacuum less of a burden.  I haven't got any specific numbers
>>to suggest, but perhaps someone else does.
>
>   It looks like that not only vacuum causes our problems. vacuum_cost
> seems to lower vacuum impact but we are still noticing slow queries "storm".
> We are logging queries that takes >2000ms to process.
>   And there is quiet periods and then suddenly 30+ slow queries appears in
> log within the same second. What else could cause such behaviour?

I've seen that happen when you're placing (explicitly or
*implicitly*) locks on the records you're trying to update/delete.

If you're willing to investigate, `pg_locks' system view holds
information about db locks.

--
Cosimo


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