Return-Path: X-Original-To: apmail-hadoop-common-issues-archive@minotaur.apache.org Delivered-To: apmail-hadoop-common-issues-archive@minotaur.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id BA51510F74 for ; Wed, 13 Nov 2013 21:51:21 +0000 (UTC) Received: (qmail 83799 invoked by uid 500); 13 Nov 2013 21:51:21 -0000 Delivered-To: apmail-hadoop-common-issues-archive@hadoop.apache.org Received: (qmail 83742 invoked by uid 500); 13 Nov 2013 21:51:21 -0000 Mailing-List: contact common-issues-help@hadoop.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: common-issues@hadoop.apache.org Delivered-To: mailing list common-issues@hadoop.apache.org Received: (qmail 83660 invoked by uid 99); 13 Nov 2013 21:51:21 -0000 Received: from arcas.apache.org (HELO arcas.apache.org) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 13 Nov 2013 21:51:21 +0000 Date: Wed, 13 Nov 2013 21:51:21 +0000 (UTC) From: "Daryn Sharp (JIRA)" To: common-issues@hadoop.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Updated] (HADOOP-9956) RPC listener inefficiently assigns connections to readers MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394 [ https://issues.apache.org/jira/browse/HADOOP-9956?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Daryn Sharp updated HADOOP-9956: -------------------------------- Resolution: Fixed Fix Version/s: 0.23.10 2.3.0 3.0.0 Hadoop Flags: Reviewed Status: Resolved (was: Patch Available) Committed to trunk/branch-2/branch-0.23. > RPC listener inefficiently assigns connections to readers > --------------------------------------------------------- > > Key: HADOOP-9956 > URL: https://issues.apache.org/jira/browse/HADOOP-9956 > Project: Hadoop Common > Issue Type: Sub-task > Components: ipc > Affects Versions: 2.0.0-alpha, 3.0.0 > Reporter: Daryn Sharp > Assignee: Daryn Sharp > Fix For: 3.0.0, 2.3.0, 0.23.10 > > Attachments: HADOOP-9956.branch-23.patch, HADOOP-9956.patch, HADOOP-9956.patch > > > The socket listener and readers use a complex synchronization to update the reader's NIO {{Selector}}. Updating active selectors is not thread-safe so precautions are required. > However, the current locking choreography results in a serialized distribution of new connections to the parallel socket readers. A slower/busier reader can stall the listener and throttle performance. > The problem manifests as unexpectedly low cpu utilization by the listener and readers (~20-30%) under heavy load. The call queue is shallow when it should be overflowing. -- This message was sent by Atlassian JIRA (v6.1#6144)