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 1uoREi-003xEE-5D for pgsql-general@arkaria.postgresql.org; Tue, 19 Aug 2025 18:39:09 +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 1uoREh-00GKj8-JE for pgsql-general@arkaria.postgresql.org; Tue, 19 Aug 2025 18:39:08 +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 1uoREg-00GKj0-OZ for pgsql-general@lists.postgresql.org; Tue, 19 Aug 2025 18:39:07 +0000 Received: from fhigh-b1-smtp.messagingengine.com ([202.12.124.152]) by makus.postgresql.org with smtp (Exim 4.96) (envelope-from ) id 1uoREe-000i0w-2y for pgsql-general@lists.postgresql.org; Tue, 19 Aug 2025 18:39:06 +0000 Received: from phl-compute-06.internal (phl-compute-06.internal [10.202.2.46]) by mailfhigh.stl.internal (Postfix) with ESMTP id AF50E7A02B0; Tue, 19 Aug 2025 14:39:04 -0400 (EDT) Received: from phl-mailfrontend-02 ([10.202.2.163]) by phl-compute-06.internal (MEProxy); Tue, 19 Aug 2025 14:39:04 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=aklaver.com; h= cc:content-transfer-encoding:content-type:content-type:date:date :from:from:in-reply-to:in-reply-to:message-id:mime-version :references:reply-to:subject:subject:to:to; s=fm2; t=1755628744; x=1755715144; bh=33knQwDFDBXHLqCVop52IiLInPVjHCaeR8Qz57FU4YQ=; b= bldUSeyheetu+b91ivnneNkoz2IskgwWM6233xFOWmlsEi1L8bKQ4TSjP+YgWn6T F2oFgUb1UBmAwNkk7D4r4nu0bKgkxYVF5yMkj8xvk9Sh39t+mMI0VmlC/C61zS9R gVjWPuEy2T5uCE2fdG1K2L22f2IRNbnf/dx3ZEMsTyfL4UIgnGmwjtKTLakRsw3Q eMYILwAeJ2tMKPdmnaXMER8USKh/uhHkiAlZ8z/CauXh2a2kXEU/SzHgBYR0SZRX JD26J6PywY0r316uaF4LRO28UZF/WAnx6DX6+jDprEmCpoduyGDsAaB594crN624 k5pXzi4RUzFZ4AHEwV6Ddg== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :content-type:date:date:feedback-id:feedback-id:from:from :in-reply-to:in-reply-to:message-id:mime-version:references :reply-to:subject:subject:to:to:x-me-proxy:x-me-sender :x-me-sender:x-sasl-enc; s=fm3; t=1755628744; x=1755715144; bh=3 3knQwDFDBXHLqCVop52IiLInPVjHCaeR8Qz57FU4YQ=; b=S2zkynQLokXKlGniA g1HWn5uw8BfIQBhYBQN93tdaZFTvkPu/d0fQHVydeyaGZ9usZhIcipounPcpJB2p KIUAbXSRcSzmjQHO0ksBumY6jEnjY98+MEpL49FHkBJddvXuWlR6Jpln43cDJ5jg WoyqMLgqKiOQnvsYUIIaYlX99AMISTx8tiyI8/K5KKrLosDCZ241o1FZjFz6rKN7 SR6PtfOIgBKjPcpmdyDv3P7IdmBSO929Lmia6MPTxcYB3j4GlG4VpnE7MGThJ4L2 sQk6fXq1pyCoVqO7mg2Yy3fvGvN7RYDPN8FiIyoqQT4l7xuzMbjwRG/ovsrTj/y2 bHaxw== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeeffedrtdefgdduheeivddvucetufdoteggodetrf dotffvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfurfetoffkrfgpnffqhgenuceu rghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujf gurhepkfffgggfuffvfhfhjggtgfesthejredttddvjeenucfhrhhomheptegurhhirghn ucfmlhgrvhgvrhcuoegrughrihgrnhdrkhhlrghvvghrsegrkhhlrghvvghrrdgtohhmqe enucggtffrrghtthgvrhhnpeeivdfhieehheegueeileejieettdejhedugeefleekvdel keehtdfgiefffeekudenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrih hlfhhrohhmpegrughrihgrnhdrkhhlrghvvghrsegrkhhlrghvvghrrdgtohhmpdhnsggp rhgtphhtthhopedvpdhmohguvgepshhmthhpohhuthdprhgtphhtthhopeguvghpvghsii esuggvphgvshiirdgtohhmpdhrtghpthhtohepphhgshhqlhdqghgvnhgvrhgrlheslhhi shhtshdrphhoshhtghhrvghsqhhlrdhorhhg X-ME-Proxy: Feedback-ID: i76984098:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Tue, 19 Aug 2025 14:39:03 -0400 (EDT) Message-ID: Date: Tue, 19 Aug 2025 11:39:03 -0700 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: Streaming replica hangs periodically for ~ 1 second - how to diagnose/debug To: depesz@depesz.com, PostgreSQL General References: Content-Language: en-US From: Adrian Klaver In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Archived-At: Precedence: bulk On 8/19/25 10:21, hubert depesz lubaczewski wrote: > Hi, > we have following situation: Pg 14.17 (yes, I know, but it can't be > upgraded now/soon), on Ubuntu focal, in AWS cloud on EC2 server using > arm64 architecture. > > All works, is fine. > > Every now and then (usually every 3-5 minutes, but not through the whole > day), we see situations where every query suddently takes ~ 1 second. > Given the subject line, what you are reporting is happening on the replica, correct? If so where is the replica relative to the primary, in terms of network distance? Also what are the 'hardware' specifications on the replica instance? -- Adrian Klaver adrian.klaver@aklaver.com