Horton

Re: [Proposal] Add foreign-server health checks infrastructure

Ted Yu <yuzhihong@gmail.com>

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From: Ted Yu <yuzhihong@gmail.com>
To: "Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, vignesh C <vignesh21@gmail.com>, "pgsql-hackers@lists.postgresql.org" <pgsql-hackers@lists.postgresql.org>, Önder Kalacı <onderkalaci@gmail.com>, Fujii Masao <masao.fujii@oss.nttdata.com>, "Shinya11.Kato@oss.nttdata.com" <Shinya11.Kato@oss.nttdata.com>, Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Date: 2023-01-10T16:38:13Z
Lists: pgsql-hackers 
On Tue, Jan 10, 2023 at 8:26 AM Hayato Kuroda (Fujitsu) <
kuroda.hayato@fujitsu.com> wrote:

> Dear tom,
>
> > I think that it's a really bad idea to require postgres_fdw.sql
> > to have two expected-files: that will be a maintenance nightmare.
> > Please put whatever it is that needs a variant expected-file
> > into its own, hopefully very small and seldom-changed, test script.
> > Or rethink whether you really need a test case that has
> > platform-dependent output.
>
> Thank you for giving the suggestion. I agreed your saying and modifed that.
>
> I added new functions on the libpq and postgres-fdw layer that check
> whether the
> checking works well or not. In the test, at first, the platform is checked
> and
> the checking function is called only when it is supported.
>
> An alternative approach is that PQCanConncheck() can be combined with
> PQConncheck().
> This can reduce the libpq function, but we must define another returned
> value to
> the function like -2. I was not sure which approach was better.
>
> Best Regards,
> Hayato Kuroda
> FUJITSU LIMITED
>

Hi,

+       /* quick exit if connection cache has been not initialized yet. */

been not initialized -> not been initialized

+
(errcode(ERRCODE_CONNECTION_FAILURE),
+                                                errmsg("could not connect
to server \"%s\"",

Currently each server which is not connected would log a warning.
Is it better to concatenate names for such servers and log one line ? This
would be cleaner when there are multiple such servers.

Cheers

Commits

  1. postgres_fdw: Extend postgres_fdw_get_connections to return user name.

  2. postgres_fdw: Fix bug in connection status check.

  3. postgres_fdw: Add connection status check to postgres_fdw_get_connections().

  4. postgres_fdw: Add "used_in_xact" column to postgres_fdw_get_connections().

  5. doc: Enhance documentation for postgres_fdw_get_connections() output columns.

  6. Avoid reference to nonexistent array element in ExecInitAgg().

  7. Add WL_SOCKET_CLOSED for socket shutdown events.

  8. postgres_fdw: reestablish new connection if cached one is detected as broken.