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

Hayato Kuroda (Fujitsu) <kuroda.hayato@fujitsu.com>

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From: "kuroda.hayato@fujitsu.com" <kuroda.hayato@fujitsu.com>

To: 'Shinya Kato' <Shinya11.Kato@oss.nttdata.com>

Cc: "pgsql-hackers@lists.postgresql.org" <pgsql-hackers@lists.postgresql.org>

Date: 2021-11-24T04:57:23Z

Lists: pgsql-hackers

Attachments

20211124.zip (application/x-zip-compressed)
v02_add_checking_infrastracture.patch (application/octet-stream) patch v2
v02_add_helth_check_for_postgres_fdw.patch (application/octet-stream) patch v2

Dear Kato-san,

Thank you for reviewing!

> Thank you for sending the patches!
> I confirmed that they can be compiled and tested successfully on CentOS
> 8.

Thanks!

> +	{
> +		{"remote_servers_connection_check_interval", PGC_USERSET,
> CONN_AUTH_SETTINGS,
> +			gettext_noop("Sets the time interval between checks
> for
> disconnection of remote servers."),
> +			NULL,
> +			GUC_UNIT_MS
> +		},
> +		&remote_servers_connection_check_interval,
> +		0, 0, INT_MAX,
> +	},
> 
> If you don't use check_hook, assign_hook and show_hook, you should
> explicitly write "NULL, NULL, NULL", as show below.

Yeah I forgot the line. Fixed.

> +			ereport(ERROR,
> +
> 	errcode(ERRCODE_CONNECTION_FAILURE),
> +					errmsg("Postgres foreign server %s
> might be down.",
> +
> 	server->servername));
> 
> According to [1], error messages should start with a lowercase letter
> and not use a period.
> Also, along with the rest of the code, it is a good idea to enclose the
> server name in double quotes.

I confirmed the postgres error-reporting policy and fixed to follow that.
How do you think?

Attached are the latest version.

Best Regards,
Hayato Kuroda
FUJITSU LIMITED

Commits

postgres_fdw: Extend postgres_fdw_get_connections to return user name.
- 4f08ab554577 18.0 landed
postgres_fdw: Fix bug in connection status check.
- 454aab4b738e 18.0 landed
postgres_fdw: Add connection status check to postgres_fdw_get_connections().
- 857df3cef7be 18.0 landed
postgres_fdw: Add "used_in_xact" column to postgres_fdw_get_connections().
- c297a47c5f8d 18.0 landed
doc: Enhance documentation for postgres_fdw_get_connections() output columns.
- 284c030a10b8 18.0 landed
Avoid reference to nonexistent array element in ExecInitAgg().
- 92957ed98c5c 16.0 cited
Add WL_SOCKET_CLOSED for socket shutdown events.
- 50e570a59e7f 15.0 cited
postgres_fdw: reestablish new connection if cached one is detected as broken.
- 32a9c0bdf493 14.0 cited