From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wido den Hollander Subject: Re: RHEL 6.5 shared library upgrade safety Date: Mon, 18 Aug 2014 14:11:00 +0200 Message-ID: <53F1ED54.2020109@42on.com> References: <53F1EA1C.1020108@dachary.org> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from websrv.42on.com ([31.25.102.167]:49349 "EHLO websrv.42on.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751118AbaHRMLD (ORCPT ); Mon, 18 Aug 2014 08:11:03 -0400 In-Reply-To: <53F1EA1C.1020108@dachary.org> Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Loic Dachary , Ceph Development On 08/18/2014 01:57 PM, Loic Dachary wrote: > Hi Ceph, > > In RHEL 6.5, is the following scenario possible : > > a) an OSD dlopen a shared library for erasure-code, > b) the shared library file is replaced while the OSD is running, > c) the OSD starts using the new file instead of the old one. > > It seems unlikely but it would explain a weird stack trace at http://tracker.ceph.com/issues/9153#note-5 so I'm double checking ;-) > Well, it could be that it does so. I'm not 100% sure, but afaik it could happen that when you replace a library certain parts might not be in memory. See: http://stackoverflow.com/questions/7767325/replacing-shared-object-so-file-while-main-program-is-running > Cheers > -- Wido den Hollander Ceph consultant and trainer 42on B.V. Phone: +31 (0)20 700 9902 Skype: contact42on