[Pgpool-general] pgpool-II 2.0.1: "pool_process_query: 1 th kind D does not match with master connection kind C" error

[Tatsuo Ishii]

> We are testing pgpool-II-2.0.1 in replication mode and are trying to figure out why pgpool-II is
> deprecating.  In our cases the system will usually run fine for 30-90 minutes processing dozens of
> transactions/second then we get the following error: pool_process_query: 1 th kind D does not match
> with master connection kind C and then pgpool drops all nodes but the master
> 
> In every case we have found it will always happen after a specific very large select statement (see
> pid1118.log).  This statement is valid and similar statements have been ran 1000's of times before
> the error occurs.

Can you be more specific? I mean If pgpool says "1 th kind D does not
match with master connection kind C", there must be data difference
among tables in both servers. Since you know the SELECT statement that
causes the error, you could manualy issues the SELECT and see
the data difference in tables. Can you veryfy it?

> I've started to look through the source code to try to figure out what's going on but that's going
> to be a slow process just to understand what should be happening.
> 
> Keen to get this resolved and could arrange access to these servers if required or clues on how to
> resolve this.

How do you INSERT/UPDATE
some_customer.wp_point,wp_sentinelconfig.gpstime? If it's default to
CURRENT_TIMESTAMP, it will not be safe for pgpool since it depends on
the timing of query execution on db1 and db2, which will not be
identical.
--
Tatsuo Ishii
SRA OSS, Inc. Japan