Re: Constantly increasing per connection memory usage on pg 9.2 - Mailing list pgsql-general

From Eliott
Subject Re: Constantly increasing per connection memory usage on pg 9.2
Date
Msg-id 52A3BAC8.5020208@gmail.com
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In response to Re: Constantly increasing per connection memory usage on pg 9.2  (Jeff Janes <jeff.janes@gmail.com>)
List pgsql-general
Hi Jeff!

No, the process that seems to grow indefinitely is postgres process created for each active connection. The app side is fine.
Altogether we have 50 tables, only two are in the 200 mb range, the rest is <50mb. While we query one of the big tables constantly (once every min) but each connection process growing to 100mb in memory footprint is something we haven't experienced with the 8.3.

Of course one solution would be to configure the connection pooler to expire the connections from time to time, but I am still not convinced that what we see is normal.

regards
Eliott

On 2013.12.07. 21:53, Jeff Janes wrote:
On Sat, Dec 7, 2013 at 1:10 AM, Eliott <eliott100@gmail.com> wrote:
Dear Community,

we've recently moved one of our production databases from a 8.3 based server to a 9.2 installation. Our usage patterns remained the same, however, we noticed that the swap space in the server started to decrease with time.

We have roughly 16 connections to this database in an almost constant basis, pooled by a java connection pooler on the app side. This connections never expire (nor did they do with the 8.3 db).
However,  as you can see on this memory usage chart http://i.imgur.com/2sRRj1J.png it shows a rolleccoaster like pattern. When we restart our application, the connections are closed and the memory is freed.

Our work_mem is 2MB, so it does not warrant the large memory allocation. Also I am completely sure that this is the pg connection process that's eating up the memory.

Is it the process on the client side or the server side that is using the memory?

How many tables are in the database?  Every additional table touched will pull in some more metadata, so over the course of a long lived connection in the pool, it could grow a lot if you have a lot of tables.

Cheers,

Jeff 

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