[pgpool-general: 2216] Re: More I/O Error in Tomcat

Josh Berkus josh at agliodbs.com
Fri Oct 25 08:42:35 JST 2013

On 10/24/2013 04:31 PM, Tatsuo Ishii wrote:
>> Tatsuo,
>> Tomcat+JDBC application connecting to PostgreSQL via pgPool II version
>> 3.3.0, installed from RPM, in Master-Slave load-balancing mode
>> (streaming replication, 1 replica).  pgPool query caching is turned off.
>> Currently we're getting repeated errors like this every few minutes on
>> Tomcat: "An I/O Error occurred while sending to the backend."
>> No errors show up in the PostgreSQL logs.
> This error happens between Tomcat and pgpool.  I suspect Tomcat
> establishes persistent connections to pgpool and pgpool disconnects it
> because client_idle_limit is not 0. Is this your case?

Yes, that sounds likely.  If we need to disable client_idle_timeout,
though, the number of DB connections bloats hopelessly; this is an
application with many databases, so we end up with several idle pgPool
connections per database.  Without client_idle_timeout, how would we
handle this?

>>  As soon as the client clears
>> them, I should be able to send you pgpool debug logs (offlist).  The
>> problem is 100% reproduceable.
> Please do so (along with pgpool.conf).

Let me test client_idle_timeout first.

Josh Berkus
PostgreSQL Experts Inc.

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