Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1sPyZ2-007Dq6-8t for pgsql-general@arkaria.postgresql.org; Sat, 06 Jul 2024 06:06:28 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.94.2) (envelope-from ) id 1sPyYz-000jJH-Ra for pgsql-general@arkaria.postgresql.org; Sat, 06 Jul 2024 06:06:26 +0000 Received: from makus.postgresql.org ([2001:4800:3e1:1::229]) by malur.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1sPyYz-000jJ8-C3 for pgsql-general@lists.postgresql.org; Sat, 06 Jul 2024 06:06:26 +0000 Received: from cloud.gatewaynet.com ([185.90.37.94]) by makus.postgresql.org with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1sPyYs-000eQv-JS for pgsql-general@lists.postgresql.org; Sat, 06 Jul 2024 06:06:24 +0000 Content-Type: multipart/alternative; boundary="------------iO5FVr6h4mbNs9lbeFl8fKmk" Message-ID: <4d1943be-b6f5-4b9b-92fb-9bd7d9ba07e5@cloud.gatewaynet.com> Date: Sat, 6 Jul 2024 09:06:13 +0300 MIME-Version: 1.0 Subject: Re: Can a long running procedure detect when smart shutdown is pending? To: Pavel Stehule , dwhite@seawardmoon.com Cc: pgsql-general@lists.postgresql.org References: <7b98efa8-9a3e-4012-8dd9-d980b5e40609@cloud.gatewaynet.com> Content-Language: en-US From: Achilleas Mantzios In-Reply-To: List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Archived-At: Precedence: bulk This is a multi-part message in MIME format. --------------iO5FVr6h4mbNs9lbeFl8fKmk Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Στις 6/7/24 08:39, ο/η Pavel Stehule έγραψε: > > > so 6. 7. 2024 v 1:36 odesílatel Dennis White > napsal: > > Thanks for responding. > This will be a stored procedure written in plpgsql that's kicked > off by pg_cron. > I wasn't sure a normal smart shutdown would stop it. > > > shutdown try to cancel any query. The plpgsql routine should be > canceled without problems. fast mode will have this effect. smart mode not, from my testing. The running queries do not get interrupted in smart shutdown. > > > > Thanks > > On Fri, Jul 5, 2024 at 4:57 PM Achilleas Mantzios > wrote: > > Στις 5/7/24 21:12, ο/η Dennis White έγραψε: >> My project's DB has a mutli-step stored procedure using >> Transaction Control that may take 30 minutes or more to complete. >> I am curious if there is a way to make it more smart shutdown >> friendly so it can stop between steps? >> >> We are using both PG 14 and PG 16 on Rhel 8. >> Pardon me if it's obvious but is there a function to call or >> a table that could be checked after a commit within the >> procedure to determine a shutdown is pending? > > Maybe somehow checking the log for a message like : > > received smart shutdown request > > Or use tail_n_mail against the log and then implement some > logic using NOTIFY , ideally you want your procedure to be > interrupted rather than do polling. > >> >> Thanks, >> Dennis > > -- > Achilleas Mantzios > IT DEV - HEAD > IT DEPT > Dynacom Tankers Mgmt (as agents only) > -- Achilleas Mantzios IT DEV - HEAD IT DEPT Dynacom Tankers Mgmt (as agents only) --------------iO5FVr6h4mbNs9lbeFl8fKmk Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: 8bit
Στις 6/7/24 08:39, ο/η Pavel Stehule έγραψε:


so 6. 7. 2024 v 1:36 odesílatel Dennis White <dwhite@seawardmoon.com> napsal:
Thanks for responding.
This will be a stored procedure written in plpgsql that's kicked off by pg_cron.
I wasn't sure a normal smart shutdown would stop it.

shutdown try to cancel any query. The plpgsql routine should be canceled without problems.
fast mode will have this effect. smart mode not, from my testing. The running queries do not get interrupted in smart shutdown.

 

Thanks

On Fri, Jul 5, 2024 at 4:57 PM Achilleas Mantzios <a.mantzios@cloud.gatewaynet.com> wrote:
Στις 5/7/24 21:12, ο/η Dennis White έγραψε:
My project's DB has a mutli-step stored procedure using Transaction Control that may take 30 minutes or more to complete.
I am curious if there is a way to make it more smart shutdown friendly so it can stop between steps?

We are using both PG 14 and PG 16 on Rhel 8.
Pardon me if it's obvious but is there a function to call or a table that could be checked after a commit within the procedure to determine a shutdown is pending?

Maybe somehow checking the log for a message like :

received smart shutdown request

Or use tail_n_mail against the log and then implement some logic using NOTIFY , ideally you want your procedure to be interrupted rather than do polling.


Thanks,
Dennis
-- 
Achilleas Mantzios
 IT DEV - HEAD
 IT DEPT
 Dynacom Tankers Mgmt (as agents only)
-- 
Achilleas Mantzios
 IT DEV - HEAD
 IT DEPT
 Dynacom Tankers Mgmt (as agents only)
--------------iO5FVr6h4mbNs9lbeFl8fKmk--