Return-Path: X-Original-To: apmail-hadoop-hdfs-issues-archive@minotaur.apache.org Delivered-To: apmail-hadoop-hdfs-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 F3347184BD for ; Wed, 5 Aug 2015 17:46:11 +0000 (UTC) Received: (qmail 68369 invoked by uid 500); 5 Aug 2015 17:46:08 -0000 Delivered-To: apmail-hadoop-hdfs-issues-archive@hadoop.apache.org Received: (qmail 68319 invoked by uid 500); 5 Aug 2015 17:46:08 -0000 Mailing-List: contact hdfs-issues-help@hadoop.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: hdfs-issues@hadoop.apache.org Delivered-To: mailing list hdfs-issues@hadoop.apache.org Received: (qmail 68304 invoked by uid 99); 5 Aug 2015 17:46:07 -0000 Received: from arcas.apache.org (HELO arcas.apache.org) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 05 Aug 2015 17:46:07 +0000 Date: Wed, 5 Aug 2015 17:46:07 +0000 (UTC) From: "Bob Hansen (JIRA)" To: hdfs-issues@hadoop.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Updated] (HDFS-7597) DNs should not open new NN connections when webhdfs clients seek 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/HDFS-7597?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Bob Hansen updated HDFS-7597: ----------------------------- Attachment: HDFS-7597.diff Refactored the diffs to move changes over to hadoop-client project > DNs should not open new NN connections when webhdfs clients seek > ---------------------------------------------------------------- > > Key: HDFS-7597 > URL: https://issues.apache.org/jira/browse/HDFS-7597 > Project: Hadoop HDFS > Issue Type: Improvement > Components: webhdfs > Affects Versions: 2.0.0-alpha > Reporter: Daryn Sharp > Assignee: Daryn Sharp > Priority: Critical > Labels: BB2015-05-TBR > Attachments: HDFS-7597.diff, HDFS-7597.patch, HDFS-7597.patch > > > Webhdfs seeks involve closing the current connection, and reissuing a new open request with the new offset. The RPC layer caches connections so the DN keeps a lingering connection open to the NN. Connection caching is in part based on UGI. Although the client used the same token for the new offset request, the UGI is different which forces the DN to open another unnecessary connection to the NN. > A job that performs many seeks will easily crash the NN due to fd exhaustion. -- This message was sent by Atlassian JIRA (v6.3.4#6332)