Do we really need any of these locks? I'm sure we could come up with some way to remove them, rather than make them distributed.
On Sun, Jun 28, 2015 at 5:07 AM, Joshua Harlow <harlo...@outlook.com> wrote: > John Griffith wrote: > >> >> >> On Sat, Jun 27, 2015 at 11:47 AM, Joshua Harlow <harlo...@outlook.com >> <mailto:harlo...@outlook.com>> wrote: >> >> Duncan Thomas wrote: >> >> We are working on some sort of distributed replacement for the >> locks in >> cinder, since file locks are limiting our ability to do HA. I'm >> afraid >> you're unlikely to get any traction until that work is done. >> >> I also have a concern that some backend do not handle load well, >> and so >> benefit from the current serialisation. It might be necessary to >> push >> this lock down into the driver and allow each driver to choose >> it's >> locking model for snapshots. >> >> >> IMHO (and I know this isn't what everyone thinks) but I'd rather >> have cinder (and other projects) be like this from top gear ( >> https://www.youtube.com/watch?v=xnWKz7Cthkk ) where that toyota >> truck is virtually indestructible vs. trying to be a >> high-maintenance ferrari (when most openstack projects do a bad job >> of trying to be one). So, maybe for a time (and I may regret saying >> this) we could consider focusing on reliability, consistency, being >> the toyota vs. handling some arbitrary amount of load (trying to be >> a ferrari). >> >> Also I'd expect/think operators would rather prefer a toyota at this >> stage of openstack :) Ok enough analogies, ha. >> >> >> Well said Josh, I guess I've been going about this all wrong by not >> using the analogies :) >> > > Exactly!! IMHO should be the new 'openstack mantra, built from > components/projects that survive like a toyota truck' haha. Part 2 ( > https://www.youtube.com/watch?v=xTPnIpjodA8) and part 3 ( > https://www.youtube.com/watch?v=kFnVZXQD5_k) are funny/interesting also > :-P > > Now we just need openstack to be that reliable and tolerant of > failures/calamities/... > > >> >> -Josh >> >> >> On 27 Jun 2015 06:18, "niuzhenguo" <niuzhen...@huawei.com >> <mailto:niuzhen...@huawei.com> >> <mailto:niuzhen...@huawei.com <mailto:niuzhen...@huawei.com>>> >> >> wrote: >> >> Hi folks,____ >> >> __ __ >> >> Currently we use a lockfile to protect the create >> operations from >> concurrent delete the source volume/snapshot, we use >> exclusive____ >> >> locks on both delete and create sides which will ensure >> that:____ >> >> __ __ >> >> __1.__If a create of VolA from snap/VolB is in progress, >> any delete >> requests for snap/VolB will wait until the create is >> complete.____ >> >> __2.__If a delete of snap/VolA is in progress, any create >> from >> snap/VolA will wait until snap/VolA delete is complte.____ >> >> __ __ >> >> but, the exclusive locks will also result in:____ >> >> __ __ >> >> __3.__If a create of VolA from snap/VolB is inprogress, any >> other >> create requests from snap/VolB will wait until the create is >> complete. ____ >> >> __ __ >> >> So the create operations from same volume/snapshot can not >> process >> on parallel, please reference bp [1].____ >> >> I’d like to change the current filelock or introduce a new >> lock to >> oslo.concurrency.____ >> >> __ __ >> >> Proposed change:____ >> >> Add exclusive(write) locks for delete operations and >> shared(read) >> locks for create operations, to ensure that create from >> volume/snapshot____ >> >> can work on parallel and protect create operations from >> concurrent >> delete the source volume/snapshot.____ >> >> __ __ >> >> I’d like to get what’s your suggestions, thanks in >> advance.____ >> >> __ __ >> >> [1] >> https://blueprints.launchpad.net/cinder/+spec/enhance-locks____ >> >> __ __ >> >> __ __ >> >> -zhenguo____ >> >> >> >> >> __________________________________________________________________________ >> OpenStack Development Mailing List (not for usage questions) >> Unsubscribe: >> openstack-dev-requ...@lists.openstack.org?subject:unsubscribe >> < >> http://openstack-dev-requ...@lists.openstack.org?subject:unsubscribe> >> < >> http://openstack-dev-requ...@lists.openstack.org?subject:unsubscribe> >> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev >> >> >> __________________________________________________________________________ >> OpenStack Development Mailing List (not for usage questions) >> Unsubscribe: >> openstack-dev-requ...@lists.openstack.org?subject:unsubscribe >> < >> http://openstack-dev-requ...@lists.openstack.org?subject:unsubscribe> >> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev >> >> >> >> __________________________________________________________________________ >> OpenStack Development Mailing List (not for usage questions) >> Unsubscribe: >> openstack-dev-requ...@lists.openstack.org?subject:unsubscribe >> <http://openstack-dev-requ...@lists.openstack.org?subject:unsubscribe >> > >> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev >> >> >> __________________________________________________________________________ >> OpenStack Development Mailing List (not for usage questions) >> Unsubscribe: >> openstack-dev-requ...@lists.openstack.org?subject:unsubscribe >> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev >> > > __________________________________________________________________________ > OpenStack Development Mailing List (not for usage questions) > Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev > -- *Avishay Traeger* *Storage R&D* Mobile: +972 54 447 1475 E-mail: avis...@stratoscale.com Web <http://www.stratoscale.com/> | Blog <http://www.stratoscale.com/blog/> | Twitter <https://twitter.com/Stratoscale> | Google+ <https://plus.google.com/u/1/b/108421603458396133912/108421603458396133912/posts> | Linkedin <https://www.linkedin.com/company/stratoscale>
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