[pgpool-general: 3186] Re: zombie connections

[Tatsuo Ishii]

Please try 3.3.4. If you still have a problem, please let us know.

Best regards,
--
Tatsuo Ishii
SRA OSS, Inc. Japan
English: http://www.sraoss.co.jp/index_en.php
Japanese:http://www.sraoss.co.jp

> Hi
> 
> We are struggling with the bellow issues for a long time - any help, even
> partial, is highly appreciated!
> 
> We use pgpool-II 3.3.3 with 4 Postrges 9.3 nodes. We are experiencing the
> following issues:
> 
> 1. In the db servers I see many idle connections (processes) for a long
> time (even days). "show pool_pools" does not show those connections so
> pgpool is not aware of them anymore. All connections to DB come from
> pg-pool so possibly it does not close the connection before killing the
> child process
> 
> 2. In "show pool_pools" I see many idle connections far behind their
> connection_life_time and even behind their pool child_life_time. The system
> was inactive for a few hours so I know for sure these connections are not
> in use.
> 
> 3. In "show pool_pools" I sometimes see multiple connections within the
> same pool with pool_connected=1. Also, I know for a fact that those client
> processes were killed a long time ago.
> 
> 
> Here is our config:
> 
> num_init_children=400
> max_pool=5
> child_life_time=300
> child_max_connections=0
> connection_life_time=60
> client_idle_limit=300
> 
> (we have 4 backends)
> 
> 
> This is example of multiple connections in the same child with
> pool_connected=1 (how can it be?).
> Also those connections are already not active for many hours (inactive
> zombie connection also happens when pool_connected=0)
> 
> pool_pid  |     start_time      | pool_id | backend_id |   database    |
>   username     |     create_time     | majorversion | minorversion |
> pool_counter | pool_backendpid | pool_connected
>  4741     | 2014-09-23 06:44:46 | 0       | 1          | DB1           |
> user1            | 2014-09-23 07:15:58 | 3            | 0            | 7
>          | 6911            | 1
>  4741     | 2014-09-23 06:44:46 | 0       | 2          | DB1           |
> user1            | 2014-09-23 07:15:58 | 3            | 0            | 7
>          | 22316           | 1
>  4741     | 2014-09-23 06:44:46 | 0       | 3          | DB1           |
> user1            | 2014-09-23 07:15:58 | 3            | 0            | 7
>          | 27441           | 1
> 
> 
> Any idea about what can cause this is highly valuable for us (even partial
> idea).
> 
> Thanks,
> Yaron