Return-Path: X-Original-To: apmail-accumulo-notifications-archive@minotaur.apache.org Delivered-To: apmail-accumulo-notifications-archive@minotaur.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id 38DF0106F6 for ; Fri, 24 Jan 2014 02:09:39 +0000 (UTC) Received: (qmail 21953 invoked by uid 500); 24 Jan 2014 02:09:38 -0000 Delivered-To: apmail-accumulo-notifications-archive@accumulo.apache.org Received: (qmail 21916 invoked by uid 500); 24 Jan 2014 02:09:38 -0000 Mailing-List: contact notifications-help@accumulo.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: jira@apache.org Delivered-To: mailing list notifications@accumulo.apache.org Received: (qmail 21904 invoked by uid 99); 24 Jan 2014 02:09:38 -0000 Received: from arcas.apache.org (HELO arcas.apache.org) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 24 Jan 2014 02:09:38 +0000 Date: Fri, 24 Jan 2014 02:09:38 +0000 (UTC) From: "Christopher Tubbs (JIRA)" To: notifications@accumulo.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Commented] (ACCUMULO-2140) Race conditions between client operations and upgrade 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/ACCUMULO-2140?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13880621#comment-13880621 ] Christopher Tubbs commented on ACCUMULO-2140: --------------------------------------------- If we explicitly say that we don't, I suppose that's fine... it reduces the footprint of this issue, but it can happen even with our own code... such as the tracer.... which is a client we explicitly start. > Race conditions between client operations and upgrade > ----------------------------------------------------- > > Key: ACCUMULO-2140 > URL: https://issues.apache.org/jira/browse/ACCUMULO-2140 > Project: Accumulo > Issue Type: Bug > Reporter: Christopher Tubbs > Assignee: Christopher Tubbs > Priority: Blocker > Fix For: 1.6.0 > > > While the master is upgrading, it also has a thread that is responding to client requests. Since the upgrade renames tables and puts them in namespaces, there is a short period of time where table existence checks that rely on the new zookeeper schema for tables are failing to provide the correct answer. > Example: when the tracer starts, it tries to create a "trace" table, if it doesn't exist. The existence check returns false, so it creates a new trace table in the default namespace, even though there exists an old one that has not yet been moved into the default namespace during the upgrade. This results in two tables with the same name. > An easy solution would be to fail to respond to client requests until after the upgrade is complete. (eg. wait to start up the MasterClientServiceHandler thread). -- This message was sent by Atlassian JIRA (v6.1.5#6160)