This feels like a bug in mongodb. We store approximately zero data in mongodb during test runs -- seriously, one machine, a charm at most, that's it. It mongodb has such amazingly high overheads just start to store data that sounds like a serious problem that is being ignored.
On Wed, May 18, 2016 at 7:32 PM, Christian Muirhead <[email protected]> wrote: > WiredTiger is *much* slower at creating and dropping indexes and > collections. I haven't worked out why that is, other than doing some > stracing and seeing that a lot of time is spent in fdatasync - I haven't dug > into the mongo source code. > There's a bit more detail in these bugs: > https://bugs.launchpad.net/juju-core/+bug/1573294 > https://jira.mongodb.org/browse/SERVER-21198 > > I've changed the tests so that instead of dropping and recreating databases > in teardown and setup we clear out all of the collections (except the > transaction collections) between tests. Obviously that's worse from the > perspective of test isolation, but it seems to work well - better than I was > expecting, to be honest. > > Cheers, > Christian > > On Wed, May 18, 2016 at 9:58 AM roger peppe <[email protected]> > wrote: >> >> Out of interest, what's causing the 3.2 slowdown and what's the hack to >> speed it up again? >> >> On 18 May 2016 09:51, "Christian Muirhead" >> <[email protected]> wrote: >>> >>> >>> >>> On Wed, May 18, 2016 at 2:04 AM David Cheney <[email protected]> >>> wrote: >>>> >>>> 100x more webscale >>> >>> Ha! >>> >>> I'm *just about* finished the hack to make the state tests on 3.2 run in >>> about the same time as on 2.4. On my machine the state tests take 6m24s on >>> 3.2 and the old version took 4m56s. Which is still worse, unfortunately, but >>> at least it isn't 100x worse. So if there are stability benefits to running >>> the tests on 3.2 it's still a win, I guess? >>> >>> >>>> >>>> >>>> On Wed, May 18, 2016 at 11:02 AM, Horacio Duran >>>> <[email protected]> wrote: >>>> > For now we are trying to go around mongo issues that make the tests >>>> > 100x >>>> > slower (yes one hundred) once this is fixed we should start using >>>> > mongo 3.2 >>>> > exclusively since 2.4 iirc is EOL or near. The issue lies in the new >>>> > storage >>>> > engine, which we could skip if mmapv1 ( the old one) wasn't also >>>> > nearing EOL >>>> > I am currently on the phone but if You want more details I can dig up >>>> > the >>>> > bug with details of what I am talking about. >>>> > >>>> > >>>> > On Tuesday, 17 May 2016, David Cheney <[email protected]> >>>> > wrote: >>>> >> >>>> >> What's the plan for mongo 3.2 ? Will we be required to support 2.x >>>> >> versions for the foreseeable future, or is there a possibility to >>>> >> make >>>> >> it a build or run time failure if mongo < 3.2 is installed on the >>>> >> host >>>> >> ? >>>> >> >>>> >> On Wed, May 18, 2016 at 9:01 AM, Martin Packman >>>> >> <[email protected]> wrote: >>>> >> > On 17/05/2016, Curtis Hovey-Canonical <[email protected]> wrote: >>>> >> >> >>>> >> >> The juju-mongo2.6 package will be be preferred by juju 1.2.5 in >>>> >> >> xenial >>>> >> >> and without other changes, 2.4 will be used by all other 1.25 >>>> >> >> series. >>>> >> > >>>> >> > This isn't yet true, there's a bug open for it: >>>> >> > >>>> >> > "Use juju-mongodb2.6 for 1.25 on xenial" >>>> >> > <https://bugs.launchpad.net/ubuntu/+source/juju-core/+bug/1570650> >>>> >> > >>>> >> > I had made the packaging change, but without juju code changes as >>>> >> > well >>>> >> > it just went and installed the old (2.4) juju-mongodb anyway when >>>> >> > setting up a state server. >>>> >> > >>>> >> > Martin >>>> >> > >>>> >> > -- >>>> >> > Juju-dev mailing list >>>> >> > [email protected] >>>> >> > Modify settings or unsubscribe at: >>>> >> > https://lists.ubuntu.com/mailman/listinfo/juju-dev >>>> >> >>>> >> -- >>>> >> Juju-dev mailing list >>>> >> [email protected] >>>> >> Modify settings or unsubscribe at: >>>> >> https://lists.ubuntu.com/mailman/listinfo/juju-dev >>>> >>>> -- >>>> Juju-dev mailing list >>>> [email protected] >>>> Modify settings or unsubscribe at: >>>> https://lists.ubuntu.com/mailman/listinfo/juju-dev >>> >>> >>> -- >>> Juju-dev mailing list >>> [email protected] >>> Modify settings or unsubscribe at: >>> https://lists.ubuntu.com/mailman/listinfo/juju-dev >>> > -- Juju-dev mailing list [email protected] Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/juju-dev
