Thread: FATAL: failed to create a backend connection

FATAL: failed to create a backend connection

From
Vikas Sharma
Date:
Hi There,

We are using Postgresql 9.3 with pgpool-II-93-3.5.10.
One Master replicating to 3 Standbys using streaming replication. Pgpool is used for load balancing only.

Lately we are seeing below on application servers.

Caused by: org.postgresql.util.PSQLException: FATAL: failed to create a backend connection
Detail: executing failover on backend

Are we hitting the max_connections in PgSql instance or pgpool has reached to max_connections and can't spawn more

Please advise.

Regards
Vikas

Re: FATAL: failed to create a backend connection

From
Pavan Teja
Date:


On Feb 2, 2018 5:57 PM, "Vikas Sharma" <shavikas@gmail.com> wrote:
Hi There,

We are using Postgresql 9.3 with pgpool-II-93-3.5.10.
One Master replicating to 3 Standbys using streaming replication. Pgpool is used for load balancing only.

Lately we are seeing below on application servers.

Caused by: org.postgresql.util.PSQLException: FATAL: failed to create a backend connection
Detail: executing failover on backend

Are we hitting the max_connections in PgSql instance or pgpool has reached to max_connections and can't spawn more

Please advise.

Regards
Vikas

    Hi,
           It seems like there is a disagreement between postgres and pgpool as to where the Unix domain sockets for talking to postgres ought to be found. 
 It's a situation like it can connect to postgres buy not pgpool, as it was directing all traffic to the local postgres node.
1) Check whether any of the postgres backends are cancelling query with 'statement time out' error.

2) If statement time out is not set in postgres.conf file then the application might have altered.

3) Check for any long running queries are being cancelled by Server.

Regards,
Pavan