Re: BUG #17776: Connections are terminated unexpectedly sometimes

Thanks for the tip, Tom!

I've checked those 4 values you suggested and they're not configured.
That means they're default.

# - TCP settings -
# see "man tcp" for details

#tcp_keepalives_idle = 0 # TCP_KEEPIDLE, in seconds;
# 0 selects the system default
#tcp_keepalives_interval = 0 # TCP_KEEPINTVL, in seconds;
# 0 selects the system default
#tcp_keepalives_count = 0 # TCP_KEEPCNT;
# 0 selects the system default
#tcp_user_timeout = 0 # TCP_USER_TIMEOUT, in milliseconds;
# 0 selects the system default

#client_connection_check_interval = 0 # time between checks for client
# disconnection while running
queries;
# 0 for never

Do you have any recommended values for them?

I found some logs I don't understand.

```
2023-02-05 00:37:16.858 UTC [1739876] [unknown](at)[unknown] FATAL:
unsupported frontend protocol 65363.19778: server supports 3.0 to 3.0
2023-02-06 12:26:48.844 UTC [467480] [unknown](at)[unknown] FATAL:
unsupported frontend protocol 16.0: server supports 3.0 to 3.0
2023-02-06 02:17:08.205 UTC [257863] [unknown](at)[unknown] FATAL:
unsupported frontend protocol 65363.19778: server supports 3.0 to 3.0
2023-02-06 06:37:00.411 UTC [345467] [unknown](at)[unknown] FATAL:
unsupported frontend protocol 0.0: server supports 3.0 to 3.0
2023-02-06 06:37:00.679 UTC [345468] [unknown](at)[unknown] FATAL:
unsupported frontend protocol 255.255: server supports 3.0 to 3.0
```
Do you have any suggestions for those logs?

Thanks

On Mon, Feb 6, 2023 at 11:39 PM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> PG Bug reporting form <noreply(at)postgresql(dot)org> writes:
> > I am running Ruby on Rails app with postgresql 14.6 on ubuntu 20.
> > For some reason, the connections are terminated unexpectedly while
> running a
> > background job.
> > Regarding background job, it requires around 100~200 connections over
> > 6~7hrs.
> > I've checked postgresql log around that time.
> > 2023-02-06 06:45:41.702 UTC [341438] user(at)db_production LOG: could not
> > receive data from client: Connection reset by peer
> > 2023-02-06 08:26:56.134 UTC [352190] user(at)db_production LOG: could not
> > receive data from client: Connection reset by peer
> > 2023-02-06 08:26:56.134 UTC [352191] user(at)db_production LOG: could not
> > receive data from client: Connection reset by peer
>
> Looks like something in your network infrastructure is timing out
> and dropping idle connections too quickly. If you can't fix the
> actual problem, Postgres' TCP-timeout settings might provide a
> workaround by maintaining an illusion that the connection is
> busy. See
>
> tcp_keepalives_count
> tcp_keepalives_idle
> tcp_keepalives_interval
> tcp_user_timeout
>
> regards, tom lane
>