From dev-return-18841-apmail-couchdb-dev-archive=couchdb.apache.org@couchdb.apache.org Wed Oct 26 23:52:40 2011 Return-Path: X-Original-To: apmail-couchdb-dev-archive@www.apache.org Delivered-To: apmail-couchdb-dev-archive@www.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id 5148776EB for ; Wed, 26 Oct 2011 23:52:40 +0000 (UTC) Received: (qmail 39706 invoked by uid 500); 26 Oct 2011 23:52:39 -0000 Delivered-To: apmail-couchdb-dev-archive@couchdb.apache.org Received: (qmail 39607 invoked by uid 500); 26 Oct 2011 23:52:39 -0000 Mailing-List: contact dev-help@couchdb.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: dev@couchdb.apache.org Delivered-To: mailing list dev@couchdb.apache.org Received: (qmail 39599 invoked by uid 99); 26 Oct 2011 23:52:39 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 26 Oct 2011 23:52:39 +0000 X-ASF-Spam-Status: No, hits=-0.7 required=5.0 tests=FREEMAIL_FROM,RCVD_IN_DNSWL_LOW,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: domain of rkalla@gmail.com designates 209.85.210.46 as permitted sender) Received: from [209.85.210.46] (HELO mail-pz0-f46.google.com) (209.85.210.46) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 26 Oct 2011 23:52:33 +0000 Received: by pzk2 with SMTP id 2so6264909pzk.5 for ; Wed, 26 Oct 2011 16:52:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=subject:references:from:content-type:x-mailer:in-reply-to :message-id:date:to:content-transfer-encoding:mime-version; bh=4R5macIhNxzTlLihZ2mtUMHId5H4gO23f7x19KyhW3c=; b=rwJRVXOKsuA97hQuVb0I3DFP50w1SDxR1T/bUdyCNMq4tAw6YzymnR3CuJNqd8sJGV vkZ5N0lcTW3HhUS3/1o6D5j9BLEMI/RB1KD+iqOrdSproOLSXX5LmIHZzT6Rj4Z1iVJ+ FZ7k+Ltog96CIGNpjR1JzmAj3qg8p8lKzonz4= Received: by 10.68.39.74 with SMTP id n10mr36263928pbk.115.1319673133218; Wed, 26 Oct 2011 16:52:13 -0700 (PDT) Received: from [192.168.0.12] (65-103-209-126.tcso.qwest.net. [65.103.209.126]) by mx.google.com with ESMTPS id wt7sm7516399pbb.16.2011.10.26.16.52.09 (version=TLSv1/SSLv3 cipher=OTHER); Wed, 26 Oct 2011 16:52:10 -0700 (PDT) Subject: Re: High latency (40ms) and low request rate (10 rps) under windows References: From: Riyad Kalla Content-Type: text/plain; charset=us-ascii X-Mailer: iPad Mail (9A334) In-Reply-To: Message-Id: <1C9ABC85-EDBD-42AB-B72A-3682977A9971@gmail.com> Date: Wed, 26 Oct 2011 16:52:14 -0700 To: "dev@couchdb.apache.org" Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 (1.0) Hmm, I see what you mean. If a single connection isnt pegging any of the har= dware and multiple connections are a magnitude times faster, I am not sure w= hat would be keeping the single connection from performning faster. Maybe someone else can hop in with ideas?=20 R On Oct 26, 2011, at 4:32 PM, Konstantin Cherkasoff w= rote: > Hi! >=20 >> What happens when you set delayed_commits to true? > With delayed_commits I got about 150 rps so delayed_commits mode is 15 > times faster. >=20 >> With that off you are requiring an fsync (iirc) after every value writte= n and then are at the >> mercy at your disks write performance (but not in the sense of burst-writ= e >> as these are individual, disparate write requests coming in). >=20 > Yes, I understand that many small writes and fsyncs can be a > bottleneck in this case. > But I found that the increase of number of concurrent requests lead to > an increase in the request rate. > For example (100 concurent requests) >> ab -k -t 10 -c 100 -n 1000000 -p ab.json -T "application/json" http://loc= alhost:5984/bench > shows about 300 RPS (writes and fsyncs) on the same hardware. >=20 > So, I suppose that 10 requests per second actually is not the limit > for this hard disk. > And there may be some other problem. >=20 >> Also, is this build Couch Single Server from Couchbase or some other Wind= ows build of Couch? > I tried Couchbase 1.2.0 and > this build https://github.com/downloads/dch/couchdb/setup-couchdb-1.1.0+CO= UCHDB-1152_otp_R14B03.exe >=20 >=20 > -- > Konstantin