From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jensen Date: Mon, 8 Jul 2013 18:37:55 +0800 Subject: [Ocfs2-devel] why oracle give up dlm by disk on ocfs2? because performance? In-Reply-To: <51D45462.5030509@oracle.com> References: <51CE541B.4070807@huawei.com> <51D22B4E.6020406@huawei.com> <51D235F8.1040503@huawei.com> <20130702172030.GF32502@wotan.suse.de> <51D37DF0.1010704@huawei.com> <51D3B163.4000308@oracle.com> <51D3E099.10908@huawei.com> <51D45462.5030509@oracle.com> Message-ID: <51DA9683.8070509@huawei.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ocfs2-devel@oss.oracle.com On 2013/7/4 0:42, Srinivas Eeda wrote: > On 07/03/2013 01:28 AM, Jensen wrote: >> On 2013/7/3 13:06, Jeff Liu wrote: >> >>> On 07/03/2013 09:27 AM, Jensen wrote: >>> >>>> On 2013/7/3 1:20, Mark Fasheh wrote: >>>> >>>>> On Tue, Jul 02, 2013 at 10:07:52AM +0800, Jensen wrote: >>>>>> On 2013/7/2 9:35, Sunil Mushran wrote: >>>>>> >>>>>>> A general purpose file system requires one to manage over a million locks concurrently. So performance is the main reason. >>>>>>> >>>>>> Thanks for your comments. >>>>>> >>>>>> Has Oracle compared the performance between ocfs2 and ocfs1? >>>>> Firstly, that's implied in the answer you just got. Also, who wouldn't >>>>> compare performance from one version of a file system to the next? >>>>> >>>>> Can you please cut to the chase and either ask what you really want to know >>>>> or make the statement you're trying to make so we can move on? >>>>> >>>> >>>> Thanks for your answer. >>>> we want to use compare and write scsi command to replace DLM module. it is similar >>>> with vmware vmfs. >>>> >>> I'm not trying to answer this question. >>> >>> I knew that OCFS2 is deployed in HuaWei.com in a large-scale cluster up >>> to 128 nodes, so I'm not very much surprised at something you mentioned >>> below, but... >>> >>>> why we want to replace dlm in ocfs2? because: >>>> 1. The stability of ocfs2 dlm is very poor, we found 100+ bug. >>> That sounds interesting, how to classify those problems? >>> - Fatal error, panic >>> - Result in an interruption in service >>> - Wrong results, but can work around? >>> - Trivial >>> >>> Reporting bugs to bugzilla/OCFS2 would be useful to keep track of them: >>> https://oss.oracle.com/bugzilla/ >>> >> >> Recently, Huawei has send many bug to open source community. > Yes and we appreciate your contributions :) >> which bug exist in >> open source. other change or bug belong to enforce ocfs2 function ,for example, when disk >> timeout, open source code will reboot the machine, we modify it, we set the ocfs2 >> invalid(can't read and write), open source may not interesting with those modify. > Can you please point me to these patches, I would be very interested to > look at. If the patches are safe for all kind of workloads and guarantee > to stop in-flight i/o's then it makes sense to add them to mainline ocfs2. >> >>> Thanks, >>> -Jeff >>> >>>> 2. The Reliability of ocfs2 dlm is very poor, especially in network split, the >>>> worse case split two domain, the half of node must be reboot. > Currently we are looking into this. It appears that most of the network > issues we are seeing may not really caused by network layer. They are > mostly false errors because o2net thread got busy. Once this happens, in > some scenarios reconnect always fails which is a bug. If you are > currently running into these problems please share so we can analyse them. >>>> 3. the maximum number of mounted machine is 32, we want to support more. >>>> >>>> currently we worry about two thing: >>>> 1. The performance lock and unlock. because it use the scsi command and it is similar with IO read and write. >>>> 2. The change is very very large. because it maybe modify the disk layout of ocfs2. > I am just curious, have you already made these changes? Are the changes > scalable? we had not made these changes. we plan to change this. >>>> >>>> so anyone interested with this? >>>> >>>>> Thanks, >>>>> --Mark >>>>> >>>>> -- >>>>> Mark Fasheh >>>>> >>>>> >>>> >>>> >>>> >>>> _______________________________________________ >>>> Ocfs2-devel mailing list >>>> Ocfs2-devel at oss.oracle.com >>>> https://oss.oracle.com/mailman/listinfo/ocfs2-devel >>> >>> >>> >> >> >> >> _______________________________________________ >> Ocfs2-devel mailing list >> Ocfs2-devel at oss.oracle.com >> https://oss.oracle.com/mailman/listinfo/ocfs2-devel > > > _______________________________________________ > Ocfs2-devel mailing list > Ocfs2-devel at oss.oracle.com > https://oss.oracle.com/mailman/listinfo/ocfs2-devel > >