[pgpool-general: 1857] Re: weird error with postgres_fdw & pgpool

[Lonni J Friedman]

I don't know any more than is documented here:
http://www.postgresql.org/docs/devel/static/postgres-fdw.html

If there's something specific that you'd like me to change or test, let me know.

thanks

On Thu, Jun 20, 2013 at 8:02 AM, Tatsuo Ishii <ishii at postgresql.org> wrote:
> No. Because I'm not familiar with postgres_fdw, I just wanted to make
> sure what the cause of the problem is. I cannot promise I can solve
> your problem, but I'm sure without knowing the cause, it's absolutely
> impossible to solve the problem.
> --
> Tatsuo Ishii
> SRA OSS, Inc. Japan
> English: http://www.sraoss.co.jp/index_en.php
> Japanese: http://www.sraoss.co.jp
>
>> 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?



--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
L. Friedman                                    netllama at gmail.com
LlamaLand                       https://netllama.linux-sxs.org