[pgpool-general: 5512] Re: Issue with parameterized query

[Tatsuo Ishii]

> Hi,
> I am having an issue with using parameterized queries with pgpool. My setup
> involves using node.js client with pgpool (3.6.4) and postgresl 9.6. I am
> using pgpool just for caching using shmem.
> 
> I have a simple example with the following query "SELECT * FROM
> master.employer where employer_id=$1".  The query returns fine the first
> time and then it gets cached. When I run it again it hits the cache, but
> returns an empty resultset.
> 
> Let me know if I can provide with any other details. I have attached the
> entire pgpool log.

In the log I see:

2017-05-18 21:13:30: pid 22781: DEBUG:  memcache: sending cached messages: 'D' len: 4917
2017-05-18 21:13:30: pid 22781: DEBUG:  memcache: sending cached messages: 'C' len: 13

which means first Pgpool-II sends 'D' (actual row data) in 4917 bytes
then 'C' (Indicating select command completed). This is perfectly sane
from the protocol's point of view. So as far as the log says,
Pgpool-II successfully returns cached data to client. So the remaining
possibility is the returned data is broken. I don't what kind of debug
method node.js has, but is it possible to capture/dump the packet data
using wireshark?

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