From commits-return-207266-archive-asf-public=cust-asf.ponee.io@cassandra.apache.org Wed Mar 7 07:05:05 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 DC303180676 for ; Wed, 7 Mar 2018 07:05:04 +0100 (CET) Received: (qmail 85497 invoked by uid 500); 7 Mar 2018 06:05:03 -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 85384 invoked by uid 99); 7 Mar 2018 06:05:03 -0000 Received: from pnap-us-west-generic-nat.apache.org (HELO spamd4-us-west.apache.org) (209.188.14.142) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 07 Mar 2018 06:05:03 +0000 Received: from localhost (localhost [127.0.0.1]) by spamd4-us-west.apache.org (ASF Mail Server at spamd4-us-west.apache.org) with ESMTP id B7A40C012E for ; Wed, 7 Mar 2018 06:05:02 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at spamd4-us-west.apache.org X-Spam-Flag: NO X-Spam-Score: -109.511 X-Spam-Level: X-Spam-Status: No, score=-109.511 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, T_RP_MATCHES_RCVD=-0.01, 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 (spamd4-us-west.apache.org [10.40.0.11]) (amavisd-new, port 10024) with ESMTP id Lev3_k55Q8UO for ; Wed, 7 Mar 2018 06:05:01 +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 4156E5F201 for ; Wed, 7 Mar 2018 06:05:01 +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 75ABAE00A7 for ; Wed, 7 Mar 2018 06:05:00 +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 335DD253FA for ; Wed, 7 Mar 2018 06:05:00 +0000 (UTC) Date: Wed, 7 Mar 2018 06:05:00 +0000 (UTC) From: "Michael Kjellman (JIRA)" To: commits@cassandra.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Commented] (CASSANDRA-14293) Speculative Retry Policy Should Support Specifying MIN/MAX of 2 PERCENTILE and FIXED Policies 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-14293?page=3Dcom.atla= ssian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId= =3D16389067#comment-16389067 ]=20 Michael Kjellman commented on CASSANDRA-14293: ---------------------------------------------- Ideally we'd express this a bit nicer by having the speculative_retry table= config option as a map, but we're bound by legacy here and have no way to = migrate and change this with the current state of schema. So, ultimately we= 'll still need to do a bunch of string parsing but we can at least get the = functionality we need with the following function-esque syntax (examples): max(99.9p,50ms) MIN(50MS,90PERCENTILE) > Speculative Retry Policy Should Support Specifying MIN/MAX of 2 PERCENTIL= E and FIXED Policies > -------------------------------------------------------------------------= -------------------- > > Key: CASSANDRA-14293 > URL: https://issues.apache.org/jira/browse/CASSANDRA-1429= 3 > Project: Cassandra > Issue Type: Improvement > Reporter: Michael Kjellman > Assignee: Michael Kjellman > Priority: Major > > Currently the Speculative Retry Policy takes a single string as a paramet= er, this can be NONE, ALWAYS, 99PERCENTILE (PERCENTILE), 50MS (CUSTOM). > The problem we have is when a single host goes into a bad state this drag= s up the percentiles. This means if we are set to use p99 alone, we might n= ot speculate when we intended to=C2=A0to because the value at the specified= percentile has gone=C2=A0so high. > As a fix we need to have support for something like min(99percentile,50ms= ) > this means if the normal p99 for the table is <50ms, we will still specul= ate at this value and not drag the happy path tail latencies up... but if t= he p99th goes above what we know we should never exceed we use that instead= . -- 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