[pgpool-general: 9329] Re: pgpool - FATAL: unable to read data from DB node 0

[Mukesh Tanuku]

Thank you!

On Sun, 2 Feb 2025 at 15:31, Tatsuo Ishii <ishii at postgresql.org> wrote:

> >> 2025-01-29 06:52:46.705: sr_check_worker pid 404220: FATAL:  unable to
> >> read data from DB node 0
> Pgpool-II's streaming replication process failed to connect to PostgreSQL.
>
> The reason is in the PostgreSQL log.
> >> 2025-01-29 06:52:43.987 UTC [404104] FATAL:  remaining connection slots
> >> are reserved for non-replication superuser connections
>
> It seems there's no usable PostgreSQL's connection slot rmaining. You
> need to either increase max_connections or reduce num_init_children
> (or both).
>
> Best reagards,
> --
> Tatsuo Ishii
> SRA OSS K.K.
> English: http://www.sraoss.co.jp/index_en/
> Japanese:http://www.sraoss.co.jp
>
> > Can someone help to understand this case
> >
> > thank you.
> >
> > On Wed, Jan 29, 2025 at 4:22 PM Mukesh Tanuku <mukesh.postgres at gmail.com
> >
> > wrote:
> >
> >> Hello Everyone,
> >>
> >> I am seeing these messages in pgpool log
> >>
> >> 2025-01-29 06:52:46.705: sr_check_worker pid 404220: FATAL:  unable to
> >> read data from DB node 0
> >> 2025-01-29 06:52:46.705: sr_check_worker pid 404220: DETAIL:  EOF
> >> encountered with backend
> >> 2025-01-29 06:52:46.705: main pid 3598: LOG:  reaper handler
> >> 2025-01-29 06:52:46.706: main pid 3598: LOG:  reaper handler: exiting
> >> normally
> >> 2025-01-29 06:52:46.706: sr_check_worker pid 404222: LOG:  process
> started
> >> 2025-01-29 06:52:46.709: sr_check_worker pid 404222: FATAL:  unable to
> >> read data from DB node 0
> >> 2025-01-29 06:52:46.709: sr_check_worker pid 404222: DETAIL:  EOF
> >> encountered with backend
> >> 2025-01-29 06:52:46.709: main pid 3598: LOG:  reaper handler
> >> 2025-01-29 06:52:46.709: main pid 3598: LOG:  reaper handler: exiting
> >> normally
> >> 2025-01-29 06:52:46.709: sr_check_worker pid 404225: LOG:  process
> started
> >> 2025-01-29 06:52:46.712: sr_check_worker pid 404225: FATAL:  unable to
> >> read data from DB node 0
> >> 2025-01-29 06:52:46.712: sr_check_worker pid 404225: DETAIL:  EOF
> >> encountered with backend
> >>
> >>
> >> what exactly this error means?
> >>
> >> in pgpool.conf we set this below,
> >>
> >> *sr_check_period = 10sr_check_user = 'monitor'*
> >>
> >>
> >> at the same time im seeing this in postgresql log file :
> >>
> >> 2025-01-29 06:52:43.987 UTC [404104] FATAL:  remaining connection slots
> >> are reserved for non-replication superuser connections
> >> 2025-01-29 06:52:46.557 UTC [404108] FATAL:  remaining connection slots
> >> are reserved for non-replication superuser connections
> >> 2025-01-29 06:52:46.562 UTC [404110] FATAL:  remaining connection slots
> >> are reserved for non-replication superuser connections
> >> 2025-01-29 06:52:46.566 UTC [404112] FATAL:  remaining connection slots
> >> are reserved for non-replication superuser connections
> >> 2025-01-29 06:52:46.569 UTC [404114] FATAL:  remaining connection slots
> >> are reserved for non-replication superuser connections
> >>
> >>
> >> We haven't set any idle_session_timeout
> >> or idle_in_transaction_session_timeout parameters in postgresql.conf
> file.
> >>
> >> Can someone help me understanding on this issue.
> >>
> >> Regards
> >> Mukesh Tanuku
> >>
>
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