[Pgpool-general] "kind does not match between backends" errors :(

[Tatsuo Ishii]

> Trying to set-up pgpool, have been trying all morning but still cant get it
> to run.

As Pablo has already pointed out, probably it's due to OID
differences. Another possiblity would be row ordering differences. Can
you enable debugging mode (add -d option to pgpool when starting up)
and see what kind of query trigger the error?

> I'm also curious to know in replication-only mode does pgpool still
> send SELECT queries to the secondary server?

I find that you set:
> weight_master = 10
> weight_secondary = 0

to expect SELECT to be sent to master only. What you are missing is
turning on load_balance_mode. Please let me know if you stil have the
problem after setting load_balance_mode to true.
--
Tatsuo Ishii

> Anyhow here is my pgpool.conf:
>  
> #
> # pgpool configuration file sample
> # $Header: /home/t-ishii/repository/pgpool/pgpool.conf.sample,v 1.19
> 2005/02/02 14:33:38 t-ishii Exp $
>  
> # host name or IP address to listen on: '*' for all, '' for no TCP/IP
> connections
> listen_addresses = '*'
>  
> # port number for pgpool
> port = 9999
>  
> # Unix domain socket path. Debian package default to /var/run/postgresql!
> socket_dir = '/tmp'
>  
> # host name where PostgreSQL server is running on. '' means localhost using
> UNIX
> # domain socket
> backend_host_name = ''
>  
> # port number PostgreSQL server is running on.
> backend_port = 5432
>  
> # Unix domain socket path for the backend. Debian package default to
> /var/run/postgresql!
> backend_socket_dir = '/tmp'
>  
> # host name where secondary PostgreSQL server is running on. '' means
> localhost using UNIX
> # domain socket
> secondary_backend_host_name = '[hidden]'
>  
> # port number secondary PostgreSQL server is running on.
> # 0 means no secondrary PostgreSQL
> secondary_backend_port = 5432
>  
> # number of pre-forked child process
> num_init_children = 32
>  
> # numer of connection pool allowed for a child process.
> max_pool = 4
>  
> # if idle for this seconds, child exits. 0 means no timeout.
> child_life_time = 300
>  
> # if idle for this seconds, connection to PostgreSQL closes. 0 means
> # no timeout
> connection_life_time = 0
>  
> # logging directory
> logdir = '/tmp'
>  
> # replication mode
> replication_mode = true
>  
> # set this to true if you want to avoid deadlock situation when
> # replication enabled.
> # there will be noticable performance degration, however.
> # a work around is set this to false and insert /*STRICT*/ comment
> # at the beginning of the SQL command.
> replication_strict = true
>  
> # when replication_strict is set to false, there will be a chance for
> # deadlocks. set this to non 0 (in milli seconds) to detect this
> # situation and resolve the deadlock aborting current session.
> replication_timeout = 10000
>  
> # load balancing mode. i.e. all SELECT except in a transaction block
> # are load balanced. This is ignored if replication_mode is false.
> load_balance_mode = false
>  
> # load balance weight for master and secondary. actual weight is
> # calculated by weight_master:weight_secondary. For example both
> #
> # weight_master = 10 and weight_secondary = 5
> # weight_master = 4 and weight_secondary = 2
> #
> # are regarded as master has double the weight comparing with secondary.
> # master and secondary have same weight in the default.
> weight_master = 10
> weight_secondary = 0
>  
> # if there's a data mismatch between master and secondary
> # start degenration to stop replication mode
> replication_stop_on_mismatch = false
>  
> # semicolon separated list of quries to be issued at the end of session
> reset_query_list = 'ABORT; RESET ALL; SET SESSION AUTHORIZATION DEFAULT'
>  
> # if true print time stamp to each log line
> print_timestamp = true
>  
> # if true, operate in master/slave mode
> master_slave_mode = false
>  
> # if true, cache connection pool
> connection_cache = true
>  
> # health check timeout. 0 means no timeout;
> health_check_timeout = 20
>  
> # health check period. 0 means no health check
> health_check_period = 0
>  
> # health check user
> health_check_user = 'nobody'
>  
> and here is my /tmp/pgpool.log:
>  
> 2005-02-24 02:51:00 ERROR: pid 1415: pool_process_query: kind does not match
> between backends master(D) secondary(C)
> 2005-02-24 02:51:00 LOG: pid 1415: do_child: exits with status 1 due to
> error
> 2005-02-24 02:51:37 ERROR: pid 1414: pool_process_query: kind does not match
> between backends master(D) secondary(C)
> 2005-02-24 02:51:37 LOG: pid 1414: do_child: exits with status 1 due to
> error
>  
> The plan is to have synchronous replication running on these 2 servers, but
> all I get is errors at this stage.
>  
> Server #1:
>     Postgres 8.0.0 on RHEL WS 3 port 5432
>     Pgpool 2.5 port 9999
>  
> Server #2:
>     Postgres 8.0.0 on RHEL WS 3 port 5432
>  
>  
> I have done a pg_dump on both servers and an md5sum and both databases are
> currently identical, same usernames, same passwords, both super users just
> in case.
>  
>  
> Any ideas?
>  
> Regards
> Paul Lee
>