The flock locks (and regular LDLM locks for Lustre metadata and data extents) are reconstructed from client state if the MDS or OSS crash.
Cheers, Andreas On Nov 26, 2017, at 21:03, John Bent <johnb...@gmail.com<mailto:johnb...@gmail.com>> wrote: How does the lock manager avoid disk IO? Locks don’t survive MDS0 failure? On Nov 26, 2017, at 8:29 PM, Dilger, Andreas <andreas.dil...@intel.com<mailto:andreas.dil...@intel.com>> wrote: The flock functionality only affects applications that are actually using it. It does not add any overhead for applications that do not use flock. There are two flock options: - localflock, which only keeps locking on the local client node and is sufficient for applications that only run on a single node - flock, which adds locking between applications on different clients mounted with this option. This is if you have a distributed application that is running on multiple clients that controls its file access via flock (e.g. Producer/consumer). The overhead itself depends on how much the application is actually using flock. The lock manager is on MDS0, and uses Lustre RPCs (which can run at 100k/s or higher), and does not involve any disk IO. Cheers, Andreas On Nov 26, 2017, at 12:03, E.S. Rosenberg <esr+lus...@mail.hebrew.edu<mailto:esr+lus...@mail.hebrew.edu>> wrote: Hi Torsten, Thanks that worked! Do you or anyone on the list know if/how flock affects Lustre performance? Thanks again, Eli On Tue, Nov 21, 2017 at 9:18 AM, Torsten Harenberg <torsten.harenb...@cern.ch<mailto:torsten.harenb...@cern.ch>> wrote: Hi Eli, Am 21.11.17 um 01:26 schrieb E.S. Rosenberg: > So I was wondering would this issue be solved by Lustre bindings for > Java or is this a way of locking that isn't supported by Lustre? I know nothing about Elastic Search, but have you tried to mount Lustre with "flock" in the mount options? Cheers Torsten -- <><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><><> <> <> <> Dr. Torsten Harenberg torsten.harenb...@cern.ch<mailto:torsten.harenb...@cern.ch> <> <> Bergische Universitaet <> <> Fakutät 4 - Physik Tel.: +49 (0)202 439-3521<tel:%2B49%20%280%29202%20439-3521> <> <> Gaussstr. 20 Fax : +49 (0)202 439-2811<tel:%2B49%20%280%29202%20439-2811> <> <> 42097 Wuppertal @CERN: Bat. 1-1-049 <> <> <> <><><><><><><>< Of course it runs NetBSD http://www.netbsd.org ><> _______________________________________________ lustre-discuss mailing list lustre-discuss@lists.lustre.org<mailto:lustre-discuss@lists.lustre.org> http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org _______________________________________________ lustre-discuss mailing list lustre-discuss@lists.lustre.org<mailto:lustre-discuss@lists.lustre.org> http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org _______________________________________________ lustre-discuss mailing list lustre-discuss@lists.lustre.org<mailto:lustre-discuss@lists.lustre.org> http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org
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