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 4.96) (envelope-from ) id 1wcdMJ-003VAd-1k for pgpool-hackers@arkaria.postgresql.org; Thu, 25 Jun 2026 06:14:43 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.96) (envelope-from ) id 1wcdMI-00479D-1d for pgpool-hackers@arkaria.postgresql.org; Thu, 25 Jun 2026 06:14:42 +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 4.96) (envelope-from ) id 1wcdMI-004796-17 for pgpool-hackers@lists.postgresql.org; Thu, 25 Jun 2026 06:14:42 +0000 Received: from meldrar.postgresql.org ([2a02:c0:301:0:ffff::31]) by makus.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.98.2) (envelope-from ) id 1wcdMG-000000008jw-0d9W for pgpool-hackers@lists.postgresql.org; Thu, 25 Jun 2026 06:14:41 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=postgresql.org; s=20171124; h=Content-Transfer-Encoding:Content-Type: Mime-Version:From:Subject:To:Message-Id:Date:Sender:Reply-To:Cc:Content-ID: Content-Description:In-Reply-To:References; bh=L1zla/mGlf92N5eU6zvzWO9OIO6+aAVoT4UC0ophsiQ=; b=jwc80f22KtJ/vSXdFbLPCBAS7A 4Sfew+P7c7Ta3f7XxcoO4cg1kFwVvQMymzLT1I6dujkIXto3fMl1i+Wb+xtSFbrWbiop4vIKBESJJ ml3QxkMfcESokgo3nRLIyZWxtPwg4FWvKu2P7+sBvWG0S1S+JdH9ona28yzfSY+pbxchSp8BzNjlB ZK7UX7p7h2uSZyGDVkqQYkfjM3jr03WC7Vzjijcdym0zkn0lL0Mq/eUymc4YP3MbdoKA20nceHBPn sEzH9ZzIsWohUXLWerLHlpdEDqiZxZLRC7p2lrIK0yZi77EiRdF+zs9CQegBXRaKd1lC+F3O1kzXw k3ZssNcQ==; Received: from [2409:11:4120:300:bd7:dd6b:4996:10fd] (helo=localhost) by meldrar.postgresql.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1wcdMC-005rX5-27 for pgpool-hackers@lists.postgresql.org; Thu, 25 Jun 2026 06:14:39 +0000 Date: Thu, 25 Jun 2026 15:14:28 +0900 (JST) Message-Id: <20260625.151428.1666276852188903568.ishii@postgresql.org> To: pgpool-hackers@lists.postgresql.org Subject: Removing support for FE/BE protocol version 2 From: Tatsuo Ishii X-Mailer: Mew version 6.8 on Emacs 29.3 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Host-Lookup-Failed: Reverse DNS lookup failed for 2409:11:4120:300:bd7:dd6b:4996:10fd (failed) List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Archived-At: Precedence: bulk PostgreSQL 14, which was released in 2021, removed protocol version 2 support. The last version supporting protocol version 2 was 13, which was EOLed in November 2025. So, existing supported PostgreSQL versions do not accept the protocol version 2 anymore (more precisely, they response with "unsupported protocol version" error when the protocol is requested). I would like to propose removing support for FE/BE protocol version 2 in upcoming v4.8. If the version 2 startup message arrives, pgpool responds with "unsupported protocol version" error, which is the same behavior as PostgreSQL server. The merits of dropping v2 protocol are: - Simplifying our code base. There are pretty large number of code path which handles v2 protocol. - Removing untested codes. Our regression tests do not include v2 protocol cases. We cannot support the version 2 protocol forever. Dropping it is only a matter of time. As I already mentioned above, all supported PostgreSQL versions finally drop the v2 protocol, I think v4.8 is the good timing to remove v2 protocol for us. Thoughts? -- Tatsuo Ishii SRA OSS K.K. English: http://www.sraoss.co.jp/index_en Japanese:http://www.sraoss.co.jp