What kind of performance issues? The current locking code only uses the presence/absence of a file for it's locking functions, and does not rely on flock/fcntl.
-- thomas On Mon, Nov 21, 2011 at 15:16, Travis Kirstine <traviskirst...@gmail.com> wrote: > Thomas, > > We have been running into some performance issues mapcache and nfs. > We feel the issue may be related to how nfs locks files/directories > compared to smb. We are trying a few thing on our end (disable > locking / nfs4 etc). Do you have any ideas? > > Regards > > On 20 October 2011 12:19, thomas bonfort <thomas.bonf...@gmail.com> wrote: >> So, this discussion inspired me to completely rework the locking >> mechanism in mapcache, to stop relying on file locks which have their >> quirks on network filesystems. >> I have tried using multiple apache instances configured to used a >> SMB-mounted lock directory and hammered both instances on unseeded >> identical area to force locking, and ended up with absolutely no >> duplicate wms requests or failed requests for the clients. >> The code is committed in trunk. Thanks for bringing this up, this >> allowed me to really simplify the locking code and remove a lot of >> unneeded stuff :) >> >> -- >> thomas >> >> On Thu, Oct 20, 2011 at 17:08, Travis Kirstine <traviskirst...@gmail.com> >> wrote: >>> Andreas and Thomas >>> >>> Thanks for you responses, I have discussed this with some of our IT >>> staff and they had similar solution as Andreas using gfs. Their >>> comments are below: >>> >>> "I suspect this scheme is not reliable over NFS. The problem is the >>> directory updates are not synchronized across multiple nodes. I had a >>> similar issue with the IMAP E-mail protocol. Our workaround currently >>> is to force each user to leverage a single server. >>> >>> Ref: >>> http://wiki.dovecot.org/NFS >>> >>> Seems like there's some tweaks to disable directory attribute caching >>> but this can trigger slower performance. >>> Only workaround is to use GFS which I found to have it's own issues. " >>> >>> Regards >>> >>> >>> >>> On 20 October 2011 05:32, Eichner, Andreas - SID-NLKM >>> <andreas.eich...@sid.sachsen.de> wrote: >>>> >>>> We use TileCache.py on two servers with the cache on an OCFS2 on a >>>> shared LUN in the SAN. No known issues with that for now. Note: Spurious >>>> stale lock files occurred already on a single machine. There seemed to >>>> be issues with lots of requests and a very slow upstream server. I used >>>> a cron job to delete lock files older than 5 minutes or so. >>>> As Thomas noted, if the lock files are created on a shared filesystem >>>> and you make sure the filesystem you use is able to lock files properly >>>> (read the docs carefully!) there's no reason why it should not work. >>>> >>> _______________________________________________ >>> mapserver-users mailing list >>> mapserver-users@lists.osgeo.org >>> http://lists.osgeo.org/mailman/listinfo/mapserver-users >>> >> > _______________________________________________ mapserver-users mailing list mapserver-users@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/mapserver-users
