[pgpool-general: 8385] Re: pgpool failing over on bad queries

[Jon SCHEWE]

>>>Syntax error itself does not trigger failover. There must be other
>>>reason which triggers the failover. To find the cause, I need to
>>>inspect the pgpool log file.
>>>
>> What should I look for in the pgpool log file?
>
>When a failover is requested, there will be a log entry something like:
>
>LOG:  received degenerate backend request for node_id: 0 from pid...
>
>> I have logs of log messages "new IPC connection received", those appear normal.
>> I also see "child process with pid ... exits with status 256" and "fork a new child process..."
>
>They are normal.
>
>> I see the following on psql-03 when the primary node changed:
>>
>> 2022-08-31 01:11:57.819: watchdog pid 971756: LOG:  watchdog received the failover command from remote pgpool-II node "psql-01:9898 Linux psql-01"
>
>I think psql-03 is the main watchdog node and it received a failover
>request from pgsql-01 watchdog. The real cause of the failover request
>is shown in the pgsql-01 log.
>
>> On psql-01 I see
>> 2022-08-31 01:11:57.818: sr_check_worker pid 2111409: LOG:  pool_ssl: "SSL_read": "no SSL error reported"
>> 2022-08-31 01:11:57.818: sr_check_worker pid 2111409: LOG:  received degenerate backend request for node_id: 0 from pid [2111409]
>
>The process which originally requested a failover was streaming
>replication check process. The error message:
>
>pool_ssl: "SSL_read": "no SSL error reported"
>
>looks strange to me because SSL reported no errors. At this point I
>have no idea why this could happen.  Possible orkaround is, disabling
>SSL for streaming replication check process.  To do so, change
>pg_hba.conf so that the user specified by sr_check_user uses non-SSL
>connection.
>

I noticed that this error message showed up on the mailing list back in 2012
https://www.pgpool.net/pipermail/pgpool-general/2012-July/000776.html
Perhaps the patch there will shed some light on this issue?