From: | Kevin Grittner <kgrittn(at)ymail(dot)com> |
---|---|
To: | Jeison Bedoya <jeisonb(at)audifarma(dot)com(dot)co>, "pgsql-performance(at)postgresql(dot)org" <pgsql-performance(at)postgresql(dot)org> |
Subject: | Re: to many locks held |
Date: | 2013-08-02 21:03:28 |
Message-ID: | 1375477408.36283.YahooMailNeo@web162901.mail.bf1.yahoo.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-performance |
Jeison Bedoya <jeisonb(at)audifarma(dot)com(dot)co> wrote:
> memory ram: 128 GB
> cores: 32
>
> max_connections: 900
> temp_buffers = 512MB
In addition to the other comments, be aware that temp_buffers is
the limit of how much RAM *each connection* can acquire to avoid
writing temporary table data to disk. Once allocated to a
connection, it will be reserved for that use on that connection
until the connection closes. So temp_buffers could lock down 450
GB of RAM even while all connections are idle. If the maximum
connections become active, and they average one work_mem allocation
apiece, that's an *additional* 900 GB of RAM which would be needed
to avoid problems.
Reducing connections through a pooler is strongly indicated, and
you may still need to reduce work_mem or temp_buffers.
http://wiki.postgresql.org/wiki/Number_Of_Database_Connections
--
Kevin Grittner
EDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
From | Date | Subject | |
---|---|---|---|
Next Message | Sergey Burladyan | 2013-08-02 21:17:13 | Re: Looks like merge join planning time is too big, 55 seconds |
Previous Message | Tom Lane | 2013-08-02 20:51:23 | Re: subselect requires offset 0 for good performance. |