Pgpool II : unable to read message length between two network interfaces

Start log file:

2015-03-06 01:57:56: pid 2760: LOG:  Setting up socket for 0.0.0.0:9999
2015-03-06 01:57:56: pid 2760: LOG:  Setting up socket for :::9999
2015-03-06 01:57:56: pid 2760: LOG:  pgpool-II successfully started. version 3.4.
0 (tataraboshi)
2015-03-06 01:57:56: pid 2760: LOG:  find_primary_node: checking backend no 0
2015-03-06 01:57:56: pid 2760: LOG:  find_primary_node: primary node id is 0
2015-03-06 01:58:02: pid 2792: ERROR:  unable to read message length
2015-03-06 01:58:02: pid 2792: DETAIL:  message length (8) in slot 1 does not mat
ch with slot 0(12)

Debug log file:

```
2015-03-06 01:55:07: pid 2680: LOG: find_primary_node: primary node id is 0
2015-03-06 01:55:42: pid 2712: DEBUG: I am 2712 accept fd 6
2015-03-06 01:55:42: pid 2712: DEBUG: reading startup packet
2015-03-06 01:55:42: pid 2712: DETAIL: Protocol Major: 1234 Minor: 5679 database
: user:
2015-03-06 01:55:42: pid 2712: DEBUG: selecting backend connection
2015-03-06 01:55:42: pid 2712: DETAIL: SSLRequest from client
2015-03-06 01:55:42: pid 2712: DEBUG: reading startup packet
2015-03-06 01:55:42: pid 2712: DETAIL: application_name: psql
2015-03-06 01:55:42: pid 2712: DEBUG: reading startup packet
2015-03-06 01:55:42: pid 2712: DETAIL: Protocol Major: 3 Minor: 0 database: post
gres user: enterprisedb
2015-03-06 01:55:42: pid 2712: DEBUG: creating new connection to backend
2015-03-06 01:55:42: pid 2712: DETAIL: connecting 0 backend
2015-03-06 01:55:42: pid 2712: DEBUG: creating new connection to backend
2015-03-06 01:55:42: pid 2712: DETAIL: connecting 1 backend
2015-03-06 01:55:42: pid 2712: DEBUG: reading message length
2015-03-06 01:55:42: pid 2712: DETAIL: slot: 0 length: 12
2015-03-06 01:55:42: pid 2712: DEBUG: reading message length
2015-03-06 01:55:42: pid 2712: DETAIL: slot: 1 length: 8
2015-03-06 01:55:42: pid 2712: ERROR: unable to read message length
2015-03-06 01:55:42: pid 2712: DETAIL: message length (8) in slot 1 does not mat
ch with slot

About errors above, because of the connection between pgpool and slave server, if I change slave's pg_hba.conf for pgpool host from md5 to trust, it work fine.

Two ways to fix:

• ssh config among: pgpool, slave, master .

• set up trust method in pg_hba.conf for pgpool .

StackExchange Database Administrators Q#94548, answer score: 2