[Pgpool-general] master_slave_mode problem

[Tatsuo Ishii]

> I am trying to use pgpool to access a pair of Slony-1 replicated databases,
> and everything works fine as long as pgpoll is only trying to contact 1 of
> the databases, but when I try to activate the master_slave_mode the
> authentification fails.
> 
> I am using pgpool 2.5.2 and PostgreSQL 7.4.7.
> 
> The debug output from pgpool when it fails is:
> 
> DEBUG: pid 24253: I am 24253 accept fd 5
> DEBUG: pid 24253: Protocol Major: 3 Minor: 0 database: XXXX user: XXXX
> DEBUG: pid 24253: read_message_length: lenghth: 12
> DEBUG: pid 24253: trying md5 authentication
> DEBUG: pid 24253: master: 1 salt: 6cb18790
> ERROR: pid 24253: pool_read: EOF encountered
> ERROR: pid 24253: do_md5_password: failed to read password packet "p"
> ERROR: pid 24253: pool_do_auth: backend does not return authenticaton ok
> DEBUG: pid 24253: I am 24253 accept fd 5
> DEBUG: pid 24253: Protocol Major: 3 Minor: 0 database: XXXX user: XXXX
> DEBUG: pid 24253: read_message_length: lenghth: 12
> DEBUG: pid 24253: trying md5 authentication
> DEBUG: pid 24253: master: 1 salt: a8968aa
> DEBUG: pid 24253: master: 0 salt: c3bc8aa
> DEBUG: pid 24253: do_md5: backend does not return R while processing MD5 authentication E
> ERROR: pid 24253: pool_do_auth: backend does not return authenticaton ok
> 
> I hope someone can help me, since we would really like to use pgpool in our
> setup, and this error prevents us from doing so.

The MD5 auth method requires a "salt" sent from PostgreSQL server in
the authentication phase. Unfortunately the salt varies time to time,
server to server, and it confuses the client, since obvioulsy it can
only accept one salt at a time. The only solution is using "clear
password" authentication or trust instead of MD5.
--
Tatsuo Ishii