You're right Joshua. Tooz HEAD points to 0f4e1198fdcbd6a29d77c67d105d201ed0fbd9e0.
With regards to etcd and zookeeper's versions, they are: zookeeper-3.4.5+28-1.cdh4.7.1.p0.13.el6.x86_64, etcd-2.2.5-2.el7.0.1.x86_64. John. On Thu, Jul 21, 2016 at 8:14 PM, Joshua Harlow <harlo...@fastmail.com> wrote: > Hi John, > > Thanks for gathering this info, > > Do you have the versions of the backend that were used here (particularly > relevant for etcd which has a new release pretty frequently). > > It'd be useful to capture that info also :) > > John Schwarz wrote: >> >> Hi everyone, >> >> Following [1], a few of us sat down during the last day of the Austin >> Summit and discussed the possibility of adding formal support for >> Tooz, specifically for the locking mechanism it provides. The >> conclusion we reached was that benchmarks should be done to show if >> and how Tooz affects the normal operation of Neutron (i.e. if locking >> a resource using Zookeeper takes 3 seconds, it's not worthwhile at >> all). >> >> We've finally finished the benchmarks and they are available at [2]. >> They test a specific case: when creating an HA router a lock-free >> algorithm is used to assign a vrid to a router (this is later used for >> keepalived), and the benchmark specifically checks the effects of >> locking that function with either Zookeeper or Etcd, using the no-Tooz >> case as a baseline. The locking was checked in 2 different ways - one >> which presents no contention (acquire() always succeeds immediately) >> and one which presents contentions (acquire() may block until a >> similar process for the invoking tenant is complete). >> >> The benchmarks show that while using Tooz does raise the cost of an >> operation, the effects are not as bad as we initially feared. In the >> simple, single simultaneous request, using Zookeeper raised the >> average time it took to create a router by 1.5% (from 11.811 to 11.988 >> seconds). On the more-realistic case of 6 simultaneous requests, >> Zookeeper raised the cost by 3.74% (from 16.533 to 17.152 seconds). >> >> It is important to note that the setup itself was overloaded - it was >> built on a single baremetal hosting 5 VMs (4 of which were >> controllers) and thus we were unable to go further - for example, 10 >> concurrent requests overloaded the server and caused some race >> conditions to appear in the L3 scheduler (bugs will be opened soon), >> so for this reason we haven't tested heavier samples and limited >> ourselves to 6 simultaneous requests. >> >> Also important to note that some kind of race condition was noticed in >> tooz's etcd driver. We've discussed this with the tooz devs and >> provided a patch that is supposed to fix them [3]. >> Lastly, races in the L3 HA Scheduler were found and we are yet to dig >> into them and find out their cause - bugs will be opened for these as >> well. >> >> I've opened the summary [2] for comments so you're welcome to open a >> discussion about the results both in the ML and on the doc itself. >> >> (CC to all those who attended the Austin Summit meeting and other >> interested parties) >> Happy locking, >> >> [1]: >> http://lists.openstack.org/pipermail/openstack-dev/2016-April/093199.html >> [2]: >> https://docs.google.com/document/d/1jdI8gkQKBE0G9koR0nLiW02d5rwyWv_-gAp7yavt4w8 >> [3]: https://review.openstack.org/#/c/342096/ >> >> -- >> John Schwarz, >> Senior Software Engineer, >> Red Hat. >> >> __________________________________________________________________________ >> 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 -- John Schwarz, Senior Software Engineer, Red Hat. __________________________________________________________________________ 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
