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 1sJjQO-006U0f-Gk for pgsql-hackers@arkaria.postgresql.org; Wed, 19 Jun 2024 00:43:44 +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 1sJjQM-006Iaq-A3 for pgsql-hackers@arkaria.postgresql.org; Wed, 19 Jun 2024 00:43:43 +0000 Received: from magus.postgresql.org ([2a02:c0:301:0:ffff::29]) by malur.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1sJjQM-006Iac-0T for pgsql-hackers@lists.postgresql.org; Wed, 19 Jun 2024 00:43:42 +0000 Received: from mail-il1-x134.google.com ([2607:f8b0:4864:20::134]) by magus.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.94.2) (envelope-from ) id 1sJjQK-002Mz5-Im for pgsql-hackers@postgresql.org; Wed, 19 Jun 2024 00:43:42 +0000 Received: by mail-il1-x134.google.com with SMTP id e9e14a558f8ab-3738690172eso25648295ab.1 for ; Tue, 18 Jun 2024 17:43:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1718757818; x=1719362618; darn=postgresql.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=P9/3r+StPiUb2cNp9m13JDEUFBX7i7Yh9NZsoPHrU7k=; b=ixW8DrNZilVLopWmvkaPqpPtI+gI7fr9DP1I6hRJOQc83QzETyBpk/A4CC0wjm8XKs jR0SRuP/Y8M23aHEWoU2XjQ9gV7AcKLwL4xYPtkcfm9mklm3mLa5b3AlRjIRKqBMFDHt THVYr6YGZpturTLQOF3SOgMm1x5p9vZJ2NTjQMbI2u5UNMJfsbHj0oWFZmG/taw2TTnb zJzz/nhcCt4rvI9jtK7nLnDmtVwZgDwv81yJDaN40rihVwrJ9DlcFZ18iKncNIOHveJ3 nPNTWHQvMIIOv0zyF0PIxAc7ZloNNC7fTyA/tRaei4TmDRLWkObfd1ULOjtKM0BmP9YX hK+w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1718757818; x=1719362618; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=P9/3r+StPiUb2cNp9m13JDEUFBX7i7Yh9NZsoPHrU7k=; b=VrcLidaBxe4xyj1G/pGA7kim//+IoATvraW04f+5gmF6NQRZcVDXiGqnQvwSqVEKwg cOBjW4SIzruNtIvw07DS7/CbgWaoumR4QhkEnPxvos7vfNBEktAqei+zqafx0AMyWa0C SP+hTsoWD0JlryLqqSc6ch4Ip2ZXZXEaUNNwGjVE+WIgGepxz/jmoazDgjyxdA0mkVQV N5DGjf2e/jVyKsrzg09Gwu+gUqUZCnIu4Vh8nYzvmfgP3P0vcBnjcbfKpV3NLec0gtDI CLvi6DQ0VyYMIdf9QxFegXDpesbOPKK37Q58yoXGIIzDMRAuuKJAFdxl6+FGcHixI/i0 CKIw== X-Forwarded-Encrypted: i=1; AJvYcCVSdqPd/gD48WgRNv8LdxbLbKbFxC6x/+BTCl3mcbrVlO7N4xkwRll6/LK4UGYckB9ReknmDHuRnsKzZgg0Wac1I+yYdNve9RMQV9NP X-Gm-Message-State: AOJu0Yz6eKpu4t2s5C/u81+kvCwAjm3p3XNeMtuDIwhBlXhqiNoMsqLl 2eWnGGMc8G7l2PKL8BF5X6Bglw3RJ2OFt6DO40pgbKaX/3o1DcWL X-Google-Smtp-Source: AGHT+IEsmDhWTZiSVb+AbsT4VXFgwtsUIUsi2j3vfK7OJjLZuDEWHVSu6fzYTKA50rd8k22HBca5Vg== X-Received: by 2002:a05:6e02:1383:b0:375:ac51:9c5e with SMTP id e9e14a558f8ab-3761d6be826mr14986685ab.15.1718757818235; Tue, 18 Jun 2024 17:43:38 -0700 (PDT) Received: from nathan (162-195-168-172.lightspeed.stlsmo.sbcglobal.net. [162.195.168.172]) by smtp.gmail.com with ESMTPSA id e9e14a558f8ab-375d86be62esm23746835ab.41.2024.06.18.17.43.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 18 Jun 2024 17:43:37 -0700 (PDT) Date: Tue, 18 Jun 2024 19:43:36 -0500 From: Nathan Bossart To: Andres Freund Cc: "Imseih (AWS), Sami" , Justin Pryzby , "pgsql-hackers@postgresql.org" Subject: Re: allow changing autovacuum_max_workers without restarting Message-ID: References: <011CA929-4933-40EA-B1D3-29131FEFBCF0@amazon.com> <20240517021646.GA1745636@nathanxps13> <20240603190852.jcibstxflb33hjvu@awork3.anarazel.de> <20240603232427.pjiyqggsr7duccr5@awork3.anarazel.de> <20240618204334.i5ar2fie4vbb3fhm@awork3.anarazel.de> <20240618213331.ef2spg3nasksisbi@awork3.anarazel.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240618213331.ef2spg3nasksisbi@awork3.anarazel.de> List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Archived-At: Precedence: bulk On Tue, Jun 18, 2024 at 02:33:31PM -0700, Andres Freund wrote: > Another one: > > Have a general cap of 64, but additionally limit it to something like > max(1, min(WORKER_CAP, max_connections / 4)) > > so that cases like tap tests don't end up allocating vastly more worker slots > than actual connection slots. That's a clever idea. My only concern would be that we are tethering two parameters that aren't super closely related, but I'm unsure whether it would cause any problems in practice. -- nathan