[pgpool-general: 1855] Re: weird error with postgres_fdw & pgpool

[Lonni J Friedman]

I'm not sure that I understand the question. Are you asking me to set
client_idle_limit to 0?

On Wed, Jun 19, 2013 at 6:15 PM, Tatsuo Ishii <ishii at postgresql.org> wrote:
> Lonni,
>
> Is it possible for postgres_fdw to create a persistent connection from
> db11 to db12 for certain pupose(maybe connection pooling)? If so, the
> connection will be treated as a normal conection from client by pgpool
> and client_idle_limit will be applied.
> --
> Tatsuo Ishii
> SRA OSS, Inc. Japan
> English: http://www.sraoss.co.jp/index_en.php
> Japanese: http://www.sraoss.co.jp
>
>> I'm in the process of testing out a beta of postgres-9.3 using
>> pgpool-3.2.4 and the (new) postgres_fdw.   I have two different
>> postgres-9.3 servers setup (db10 & db11), and pgpool is setup (db12)
>> pointing to one of them (db10).  I can connect with psql to both
>> servers directly, and also via pgpool, with no problems.  My intent
>> was to be able to run SQL queries while logged into db11 through
>> pgpool on db12 to the server on db10, using a postgres_fdw.
>>
>> I setup the postgres_fdw server:
>> CREATE SERVER db10 FOREIGN DATA WRAPPER postgres_fdw OPTIONS (host
>> 'db12', dbname 'nightly', port '9999');
>> CREATE USER MAPPING FOR lfriedman SERVER db10 OPTIONS (user 'lfriedman');
>> CREATE FOREIGN TABLE nppsmoke (id bigint NOT NULL, date_created
>> timestamp without time zone not null default now(), last_update
>> timestamp without time zone not null default now(), build_type text
>> NOT NULL,current_status text NOT NULL, info text NOT NULL, cudacode
>> text NOT NULL, gpu text NOT NULL, subtest text NOT NULL, os text NOT
>> NULL, osversion text NOT NULL, arch text NOT NULL, cl integer NOT
>> NULL, dispvers text NOT NULL, branch text NOT NULL, pass integer,fail
>> integer, oldfail integer, newfail integer, failureslog text, totdriver
>> boolean NOT NULL default 'true',ddcl integer NOT NULL, buildid
>> integer, testdcmd text NOT NULL, pclog text, filtercount integer,
>> filterlog text, error integer) SERVER db10 ;
>>
>> After which, I verified that I could issue SQL queries from inside
>> psql while connected to db11, against the foreign table, nppsmoke that
>> was created above:
>> #########
>> nightly=# select last_update from nppsmoke where id='86901' ;
>>      last_update
>> ---------------------
>>  2013-06-12 12:53:23
>> (1 row)
>> #########
>>
>> However, I'm seeing some strange errors when my psql session exceeds
>> the pgpool client_idle_limit:
>> #######
>> nightly=# select last_update from nppsmoke where id='86901' ;
>> ERROR:  connection terminated due to client idle limit reached
>> CONTEXT:  Remote SQL command: START TRANSACTION ISOLATION LEVEL REPEATABLE READ
>> nightly=# select last_update from nppsmoke where id='86901' ;
>> ERROR:  unknown error
>> CONTEXT:  Remote SQL command: START TRANSACTION ISOLATION LEVEL REPEATABLE READ
>> ########
>>
>> And the only way that I've found to run the SQL queries against the
>> foreign table is to exit psql and connect again from scratch.  This is
>> definitely different behavior than I experience for local tables.  For
>> queries issued after the client_idle_limit, I always see:
>> #####
>> ERROR:  connection terminated due to client idle limit reached
>> ERROR:  connection terminated due to client idle limit reached
>> The connection to the server was lost. Attempting reset: Succeeded.
>> #####
>>
>> after which I can re-run the query without exiting & reconnecting with psql.
>>
>> This seems like a bug to me, as I'd expect the behavior to be
>> consistent regardless of what is on the remote end.  Thoughts?