+1. This really helps PostgreSQL Azure service as well. When we are doing the upgrades to the service, instead of abruptly terminating the sessions we can provide this message.
Thanks, Satya From: pgsql-hackers-ow...@postgresql.org [mailto:pgsql-hackers-ow...@postgresql.org] On Behalf Of Pavel Stehule Sent: Monday, June 19, 2017 11:41 AM To: Daniel Gustafsson <dan...@yesql.se> Cc: PostgreSQL mailing lists <email@example.com> Subject: Re: [HACKERS] Optional message to user when terminating/cancelling backend 2017-06-19 20:24 GMT+02:00 Daniel Gustafsson <dan...@yesql.se<mailto:dan...@yesql.se>>: When terminating, or cancelling, a backend it’s currently not possible to let the signalled session know *why* it was dropped. This has nagged me in the past and now it happened to come up again, so I took a stab at this. The attached patch implements the ability to pass an optional text message to the signalled session which is included in the error message: SELECT pg_terminate_backend(<pid> [, message]); SELECT pg_cancel_backend(<pid> [, message]); Right now the message is simply appended on the error message, not sure if errdetail or errhint would be better? Calling: select pg_terminate_backend(<pid>, 'server rebooting'); ..leads to: FATAL: terminating connection due to administrator command: "server rebooting" Omitting the message invokes the command just like today. The message is stored in a new shmem area which is checked when the session is aborted. To keep things simple a small buffer is kept per backend for the message. If deemed too costly, keeping a central buffer from which slabs are allocated can be done (but seemed rather complicated for little gain compared to the quite moderate memory spend.) cheers ./daniel +1 very good idea Pavel -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org<mailto:email@example.com>) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers<https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.postgresql.org%2Fmailpref%2Fpgsql-hackers&data=02%7C01%7CSatyanarayana.Narlapuram%40microsoft.com%7C8f211f53d54c4d6308d308d4b742f824%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636334945639579811&sdata=VH8ljYHI%2BaxoNdM7pYLpfEqa%2FbXWf0dRptoNzxElbaA%3D&reserved=0>