Re: [Postgres-xc-general] ERROR: sorry, too many clients already

[Mason S. <ms...@tr...>]

On Tue, Jul 1, 2014 at 6:59 AM, Wilkerson, Daniel <dwi...@fu...>
wrote:

> Hey everyone. I have my cluster up and running using pgxc_ctl instead of
> manually configuring (XC 1.1; Ubuntu 13.04). It's definitely easier to
> setup and control the cluster this way for sure. I have HAProxy balancing
> the requests to the servers. It's working fine also.
>
> All of the nodes startup fine and everything seems ok on the surface; that
> is until I run the DDL script to create my database across all the nodes.
> During script execution I get, "ERROR: sorry, too many clients already".
> I've tried upping the number of available connections but still get the
> same issue across the cluster. I am executing the DDL against my first
> coordinator.
>
> Could this be a mismatch in my config of the proportions between shared
> mem and max connections? I've queried the database and it doesn't report
> tons of connections. I'm not sure where to look in my config to suss out
> the problem.
>
> I appreciate any light you all could shed on this. I'm fairly certain it's
> something I need to tweak in my config somewhere, but also want to make
> sure I've not run up against a bug.
>
> Thanks!
> dw
>
>
> Connection values entered into the pgxc_ctl cluster config:
> max_connections = 200
> max_pool_size = 200
>

These should be appended in the individual nodes' postgresql.conf files.  I
would double-check there, adding them manually if necessary.



>
> This is a snippet from the script erring out.
> …
> CREATE TABLE
> CREATE SEQUENCE
> ALTER SEQUENCE
> CREATE TABLE
> CREATE SEQUENCE
> ALTER SEQUENCE
> CREATE TABLE
> CREATE SEQUENCE
> ALTER SEQUENCE
> psql:db.sql:2654: WARNING:  unexpected EOF on datanode connection
> psql:db.sql:2654: WARNING:  unexpected EOF on datanode connection
> psql:db.sql:2654: ERROR:  sorry, too many clients already
>
>
> This snippet from ps –ef | grep post on my first coordinator/datanode
> combo shows a hung create table statement:
>
> postgre+  3608  3588  0 09:39 pts/1    00:00:00 psql -p 20004 -d postgres
> postgre+  3616  2980  0 09:40 ?        00:00:00 postgres: postgres-xc db
> [local] CREATE TABLE
> postgre+  3644  3291  0 09:41 ?        00:00:00 postgres: checkpointer
> process
> postgre+  3645  3291  0 09:41 ?        00:00:00 postgres: writer process
> postgre+  3646  3291  0 09:41 ?        00:00:00 postgres: wal writer
> process
> postgre+  3647  3291  0 09:41 ?        00:00:00 postgres: autovacuum
> launcher process
> postgre+  3648  3291  0 09:41 ?        00:00:00 postgres: stats collector
> process
> postgre+  3705  2553  0 09:48 pts/0    00:00:00 ps -ef
> postgre+  3706  2553  0 09:48 pts/0    00:00:00 grep post
>

OTOH, this does not look like very much activity at all... there should be
plenty of connections.


-- 
Mason Sharp

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