From commits-return-209146-archive-asf-public=cust-asf.ponee.io@cassandra.apache.org Wed Apr 18 06:15:04 2018 Return-Path: X-Original-To: archive-asf-public@cust-asf.ponee.io Delivered-To: archive-asf-public@cust-asf.ponee.io Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by mx-eu-01.ponee.io (Postfix) with SMTP id 32ACB180649 for ; Wed, 18 Apr 2018 06:15:04 +0200 (CEST) Received: (qmail 31489 invoked by uid 500); 18 Apr 2018 04:15:03 -0000 Mailing-List: contact commits-help@cassandra.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: dev@cassandra.apache.org Delivered-To: mailing list commits@cassandra.apache.org Received: (qmail 31478 invoked by uid 99); 18 Apr 2018 04:15:03 -0000 Received: from pnap-us-west-generic-nat.apache.org (HELO spamd1-us-west.apache.org) (209.188.14.142) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 18 Apr 2018 04:15:03 +0000 Received: from localhost (localhost [127.0.0.1]) by spamd1-us-west.apache.org (ASF Mail Server at spamd1-us-west.apache.org) with ESMTP id 7AFCCC1486 for ; Wed, 18 Apr 2018 04:15:02 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at spamd1-us-west.apache.org X-Spam-Flag: NO X-Spam-Score: -109.501 X-Spam-Level: X-Spam-Status: No, score=-109.501 tagged_above=-999 required=6.31 tests=[ENV_AND_HDR_SPF_MATCH=-0.5, KAM_ASCII_DIVIDERS=0.8, RCVD_IN_DNSWL_MED=-2.3, SPF_PASS=-0.001, USER_IN_DEF_SPF_WL=-7.5, USER_IN_WHITELIST=-100] autolearn=disabled Received: from mx1-lw-eu.apache.org ([10.40.0.8]) by localhost (spamd1-us-west.apache.org [10.40.0.7]) (amavisd-new, port 10024) with ESMTP id hvXiA4FpPv3I for ; Wed, 18 Apr 2018 04:15:01 +0000 (UTC) Received: from mailrelay1-us-west.apache.org (mailrelay1-us-west.apache.org [209.188.14.139]) by mx1-lw-eu.apache.org (ASF Mail Server at mx1-lw-eu.apache.org) with ESMTP id 3EEE25FB29 for ; Wed, 18 Apr 2018 04:15:01 +0000 (UTC) Received: from jira-lw-us.apache.org (unknown [207.244.88.139]) by mailrelay1-us-west.apache.org (ASF Mail Server at mailrelay1-us-west.apache.org) with ESMTP id 7F442E0309 for ; Wed, 18 Apr 2018 04:15:00 +0000 (UTC) Received: from jira-lw-us.apache.org (localhost [127.0.0.1]) by jira-lw-us.apache.org (ASF Mail Server at jira-lw-us.apache.org) with ESMTP id 34BCB21208 for ; Wed, 18 Apr 2018 04:15:00 +0000 (UTC) Date: Wed, 18 Apr 2018 04:15:00 +0000 (UTC) From: "Chris Lohfink (JIRA)" To: commits@cassandra.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Updated] (CASSANDRA-14281) Improve LatencyMetrics performance by reducing write path processing MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394 [ https://issues.apache.org/jira/browse/CASSANDRA-14281?page=3Dcom.atl= assian.jira.plugin.system.issuetabpanels:all-tabpanel ] Chris Lohfink updated CASSANDRA-14281: -------------------------------------- Attachment: benchmark.html > Improve LatencyMetrics performance by reducing write path processing > -------------------------------------------------------------------- > > Key: CASSANDRA-14281 > URL: https://issues.apache.org/jira/browse/CASSANDRA-1428= 1 > Project: Cassandra > Issue Type: Improvement > Components: Core > Reporter: Michael Burman > Assignee: Michael Burman > Priority: Major > Attachments: bench.png, bench2.png, benchmark.html, benchmark2.pn= g > > > Currently for each write/read/rangequery/CAS touching the CFS we write a = latency metric which takes a lot of processing time (up to 66% of the total= processing time if the update was empty).=C2=A0 > The way latencies are recorded is to use both a dropwizard "Timer" as wel= l as "Counter". Latter is used for totalLatency and the previous is decayin= g metric for rates and certain percentile metrics. We then replicate all of= these CFS writes to the KeyspaceMetrics and globalWriteLatencies.=C2=A0 > Instead of doing this on the write phase we should merge the metrics when= they're read. This is much less common occurrence and thus we save a lot o= f CPU time in total. This also speeds up the write path. > Currently, the=C2=A0DecayingEstimatedHistogramReservoir acquires a lock f= or each update operation, which causes a contention if there are more than = one thread updating the histogram. This impacts scalability when using larg= er machines. We should make it lock-free as much as possible and also avoid= a single CAS-update from blocking all the concurrent threads from making a= n update. -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscribe@cassandra.apache.org For additional commands, e-mail: commits-help@cassandra.apache.org