[Pgpool-general] Trouble with pgpool installation

[Tatsuo Ishii]

> I've used Postgres for several years now, and I am just starting to
> play with pgpool.  For my test configuration we have two servers:
> 
> srvh016 - pgpool, postgres node, and pgpool system_db
> srvh035 - Postgres node
> 
> I've followed the tutorial here:
> http://pgpool.projects.postgresql.org/contrib_docs/simple_sr_setting2/
> 
> Overall I had no difficultly with the instructions.  One issue I had
> involved creating a pool_passwd file with pg_md5.  The other issue I
> had was the default value for delay_threshold in pgpool.conf  I had to
> lower this value to around 10000 before pgpoolAdmin would accept the
> configuration.
> 
> However, my pgpoolAdmin does not list any nodes, and in the log, I see:
> 
> LOG:   pid 8699: Backend status file /tmp/pgpool_status discarded
> LOG:   pid 8699: pgpool-II successfully started. version 3.0.4 (umiyameboshi)
> LOG:   pid 8699: find_primary_node: primary node id is 0
> ERROR: pid 8733: check_replication_time_lag: SELECT
> pg_last_xlog_receive_location() returns no data
> ERROR: pid 8733: check_replication_time_lag: SELECT
> pg_last_xlog_receive_location() returns no data
> ERROR: pid 8733: check_replication_time_lag: SELECT
> pg_last_xlog_receive_location() returns no data
> ...
> 
> If I try on my own:
> 
> postgres=# select pg_last_xlog_receive_location();
>  pg_last_xlog_receive_location
> -------------------------------
> 
> (1 row)
> 
> Not sure what is expected.

pg_last_xlog_receive_location only returns meaningfull result on
standby. You should connect directly to standby and issue the
query. Even if you do that, I suspect you will get NULL since pgpool
log says however.

> ERROR: pid 8733: check_replication_time_lag: SELECT
> pg_last_xlog_receive_location() returns no data

This indicates that your standby server does not act as standby. You
should check your standby postgres log.

> I did create a pgpool database and pgpool owner role.  I then ran
> system_db.sql on that database, so I figured the system DB
> configuration is complete

I'm confused. streaming replication mode does not require system
db. Why did you do so?

> Any help with this is greatly appreciated.  I am using pgpool-II-3.0.4
> and pgpoolAdmin-3.0.3.
> 
> Thank you,
> Paul