PgPool fails to auth in master_slave mode We have two PostgreSQL servers running in master-slave streaming replication mode, behind pgpool.

When we activate master_slave mode in pgpool.conf, we get following error:

do_md5 failed in slot 1


When we add a host with the md5 method in pool_hba.conf, we're getting this error:

md5 token is invalid


Without master_slave mode, pgpool connects successfully. Where to dig?
Solution, in 2 words: install latest pgpool2 from sources

Step by step solution: 


Make sure that you have pgpool2 with version 3+
Create pool_passwd with pg_md5 command
Make sure, that you have md5 in pool_hba.conf. If you have pgpool2 from deb - it will not support md5 token in pool_hba.conf