Managing PgPool is not easy and you may see multiple issues during configuration and management of PgPool. This series will address some of the common errors/issues :
1)Different entries in pg_hba entries
Lets say you have 3 nodes in your PgPool cluster , you updated pg_hba entry in one of the node but forgot to apply the same on other nodes you would see an error like below
-bash-4.2$ psql -d postgres -U postgres -h 127.0.0.1 -p 5432 -c "show pool_nodes" ; psql: error: could not connect to server: ERROR: unable to read message kind DETAIL: kind does not match between master(52) slot[1] (45)Above error message is hard to comprehend as it did not state anywhere about hba entries. As soon as you match hba entries it should start working again
2)PgPool streaming replication check error
In the PgPool config file you need to make sure you have right credentials for streaming replication health check or else you would see error similar to the one stated below
pgpool find_primary_node: make_persistent_db_connection_noerror failed on node
3) SCRAM method error
When you are using scram auth you may see an error like below . Root cause of the below issue is that you need to define passwords at PgPool level as well in pool_pswd file
bash-4.2$ psql -d postgres -U postgres -h 127.0.0.1 -p 5432 psql: error: could not connect to server: ERROR: failed to authenticate with backend using SCRAM DETAIL: valid password not found -bash-4.2$
4)Make sure you enable PgPool to accept connections using below parameter or else you may see issues
Listen_address=’*’