Return-Path: X-Original-To: archive-asf-public-internal@cust-asf2.ponee.io Delivered-To: archive-asf-public-internal@cust-asf2.ponee.io Received: from cust-asf.ponee.io (cust-asf.ponee.io [163.172.22.183]) by cust-asf2.ponee.io (Postfix) with ESMTP id 99898200BF1 for ; Tue, 3 Jan 2017 17:59:01 +0100 (CET) Received: by cust-asf.ponee.io (Postfix) id 982ED160B20; Tue, 3 Jan 2017 16:59:01 +0000 (UTC) Delivered-To: archive-asf-public@cust-asf.ponee.io Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by cust-asf.ponee.io (Postfix) with SMTP id ED2F3160B46 for ; Tue, 3 Jan 2017 17:59:00 +0100 (CET) Received: (qmail 38920 invoked by uid 500); 3 Jan 2017 16:58:58 -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 38107 invoked by uid 99); 3 Jan 2017 16:58:58 -0000 Received: from arcas.apache.org (HELO arcas) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 03 Jan 2017 16:58:58 +0000 Received: from arcas.apache.org (localhost [127.0.0.1]) by arcas (Postfix) with ESMTP id 6B9222C2A67 for ; Tue, 3 Jan 2017 16:58:58 +0000 (UTC) Date: Tue, 3 Jan 2017 16:58:58 +0000 (UTC) From: "Joel Knighton (JIRA)" To: commits@cassandra.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Commented] (CASSANDRA-13074) DynamicEndpointSnitch frequently no-ops through early exit in multi-datacenter situations MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394 archived-at: Tue, 03 Jan 2017 16:59:01 -0000 [ https://issues.apache.org/jira/browse/CASSANDRA-13074?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15795527#comment-15795527 ] Joel Knighton commented on CASSANDRA-13074: ------------------------------------------- [~tjake] - A dtest is a great idea. I've PRed a test to [riptano/cassandra-dtest|https://github.com/riptano/cassandra-dtest/pull/1416]. > DynamicEndpointSnitch frequently no-ops through early exit in multi-datacenter situations > ----------------------------------------------------------------------------------------- > > Key: CASSANDRA-13074 > URL: https://issues.apache.org/jira/browse/CASSANDRA-13074 > Project: Cassandra > Issue Type: Bug > Components: Coordination > Reporter: Joel Knighton > Assignee: Joel Knighton > Fix For: 2.2.x, 3.0.x, 3.x, 4.x > > > The DynamicEndpointSnitch attempts to use timings from nodes to route reads to better performing nodes. > In a multi-datacenter situation, timings will likely be empty for nodes outside of the local datacenter, as you'll frequently only be doing local_quorum reads (or a lower consistency level). In this case, the DES exits early and returns the subsnitch ordering. This means poorly performing replicas will never be avoided, no matter how degraded they are. -- This message was sent by Atlassian JIRA (v6.3.4#6332)