Re: Rename max_parallel_degree?
Michael Paquier <michael.paquier@gmail.com>
From: Michael Paquier <michael.paquier@gmail.com>
To: Julien Rouhaud <julien.rouhaud@dalibo.com>
Cc: Robert Haas <robertmhaas@gmail.com>, Peter Eisentraut <peter.eisentraut@2ndquadrant.com>,
Amit Kapila <amit.kapila16@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>, Josh Berkus <josh@agliodbs.com>, "David G. Johnston" <david.g.johnston@gmail.com>,
Peter Geoghegan <pg@heroku.com>, Noah Misch <noah@leadboat.com>, David Rowley <david.rowley@2ndquadrant.com>, Alvaro Herrera <alvherre@2ndquadrant.com>,
Magnus Hagander <magnus@hagander.net>, Bruce Momjian <bruce@momjian.us>,
PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2016-10-03T02:20:27Z
Lists: pgsql-hackers
On Sat, Oct 1, 2016 at 1:23 AM, Julien Rouhaud <julien.rouhaud@dalibo.com> wrote: > On 23/09/2016 21:10, Robert Haas wrote: >> On Fri, Sep 23, 2016 at 8:54 AM, Peter Eisentraut >> <peter.eisentraut@2ndquadrant.com> wrote: >>> On 9/20/16 4:07 PM, Robert Haas wrote: >>>> No, I'm assuming that the classes would be built-in. A string tag >>>> seems like over-engineering to me, particularly because the postmaster >>>> needs to switch on the tag, and we need to be very careful about the >>>> degree to which the postmaster trusts the contents of shared memory. >>> >>> I'm hoping that we can come up with something that extensions can >>> participate in, without the core having to know ahead of time what those >>> extensions are or how they would be categorized. >>> >>> My vision is something like >>> >>> max_processes = 512 # requires restart >>> >>> process_allowances = 'connection:300 superuser:10 autovacuum:10 >>> parallel:30 replication:10 someextension:20 someotherextension:20' >>> # does not require restart >> >> I don't think it's going to be very practical to allow extensions to >> participate in the mechanism because there have to be a finite number >> of slots that is known at the time we create the main shared memory >> segment. >> >> Also, it's really important that we don't add lots more surface area >> for the postmaster to crash and burn. >> > > It seems that there's no objection on Robert's initial proposal, so I'll > try to implement it. > > I've already fixed every other issues mentioned upthread, but I'm facing > a problem for this one. Assuming that the bgworker classes are supposed > to be mutually exclusive, I don't see a simple and clean way to add such > a check in SanityCheckBackgroundWorker(). Am I missing something > obvious, or can someone give me some advice for this? Okay, so marking it as returned with feedback is adapted? I have done so but feel free to contradict me. -- Michael