(sent too soon)
Summary:
before:
1043 local.oplog.rs
868 juju.txns
470 juju.leases
after:
802 local.oplog.rs
625 juju.txns
267 juju.leases
So there seems to be a fairly noticeable decrease in load on the system
around leases (~70%). Again, not super scientific because I didn't measure
over enough time, deal with variation, all that kind of stuff. But at least
at a glimpse it looks pretty good.
As far as load around the global clock:
juju.globalclock 5ms 3ms 1ms
juju.globalclock 10ms 8ms 1ms
etc
So generally noticeable, but not specifically an issue.
Hopefully we'll see similar improvements in live systems. The main thing is
to make sure upgrade is smooth from 2.2 to 2.3 since the lease issue was a
pretty major crash of the system.
John
=:->
On Wed, Nov 1, 2017 at 6:43 PM, John A Meinel <john.mei...@canonical.com>
wrote:
> So I wanted to know if Andrew's changes in 2.3 are going to have a
> noticeable affect at scale on Leadership. So I went and set up a test with
> HA controllers running 10 machines each with 3 containers, and then
> distributing ~500 applications each with 3 units across everything.
> I started at commit 2e50e5cf4c3 which is just before Andrew's Lease patch
> landed.
>
> juju bootstrap aws/eu-west-2 --bootstrap-constraint
> instance-type=m4.xlarge --config vpc-id=XXXX
> juju enable-ha -n3
> # Wait for things to stablize
> juju deploy -B cs:~jameinel/ubuntu-lite -n10 --constraints
> instance-type=m4.xlarge
> # wait
>
> #set up the containers
> for i in `seq 0 9`; do
> juju deploy -n3 -B cs:~jameinel/ubuntu-leader ul --to
> lxd:${i},lxd:${i},lxd:${i}
> done
>
> # scale up. I did this more in batches of a few at a time, but slowly grew
> all the way up
> for j in `seq 1 49`; do
> echo $j
> for i in `seq 0 9`; do
> juju deploy -B -n3 cs:~jameinel/ubuntu-leader ul${i}{$j} --to
> ${i}/lxd/0,${i}/lxd/1,${i}/lxd/2 &
> done
> time wait
> done
>
> I let it go for a while until "juju status" was happy that everything was
> up and running. Note that this was 1500 units, 500 applications in a single
> model.
> time juju status was around 4-10s.
>
> I was running 'mongotop' and watching 'top' while it was running.
>
> I then upgraded to the latest juju dev (c49dd0d88a).
> Now, the controller immediately started thrashing, with bad lease
> documents in the database, and eventually got to the point that it ran out
> of open file descriptors. Theoretically upgrading 2.2 => 2.3 won't have the
> same problem because the actual upgrade step should run.
> However, if I just did "db.leases.remove({})" it recovered.
> I ended up having to restart mongo and jujud to recover from the open file
> handles, but it did eventually recover.
>
> At this point, I waited again for everything to look happy, and watch
> mongotop and top again.
>
> These aren't super careful results, where I would want to run things for
> like an hour each and check the load over that whole time. Really I should
> have set up prometheus monitoring. But as a quick check, these are the top
> values for mongotop before:
>
> ns total read write
> local.oplog.rs 181ms 181ms 0ms
> juju.txns 120ms 10ms 110ms
> juju.leases 80ms 34ms 46ms
> juju.txns.log 24ms 4ms 19ms
>
> ns total read write
> local.oplog.rs 208ms 208ms 0ms
> juju.txns 140ms 12ms 128ms
> juju.leases 98ms 42ms 56ms
> juju.charms 43ms 43ms 0ms
>
> ns total read write
> local.oplog.rs 220ms 220ms 0ms
> juju.txns 161ms 14ms 146ms
> juju.leases 115ms 52ms 63ms
> presence.presence.beings 69ms 68ms 0ms
>
> ns total read write
> local.oplog.rs 213ms 213ms 0ms
> juju.txns 164ms 15ms 149ms
> juju.leases 82ms 35ms 47ms
> presence.presence.beings 79ms 78ms 0ms
>
> ns total read write
> local.oplog.rs 221ms 221ms 0ms
> juju.txns 168ms 13ms 154ms
> juju.leases 95ms 40ms 55ms
> juju.statuses 33ms 16ms 17ms
>
> totals:
> 1043 local.oplog.rs
> juju.txns 868
> juju.leases 470
>
> and after
>
> ns total read write
> local.oplog.rs 95ms 95ms 0ms
> juju.txns 68ms 6ms 61ms
> juju.leases 33ms 13ms 19ms
> juju.txns.log 13ms 3ms 10ms
>
> ns total read write
> local.oplog.rs 200ms 200ms 0ms
> juju.txns 160ms 10ms 150ms
> juju.leases 78ms 35ms 42ms
> juju.txns.log 29ms 4ms 24ms
>
> ns total read write
> local.oplog.rs 151ms 151ms 0ms
> juju.txns 103ms 6ms 97ms
> juju.leases 45ms 20ms 25ms
> juju.txns.log 21ms 6ms 15ms
>
> ns total read write
> local.oplog.rs 138ms 138ms 0ms
> juju.txns 98ms 6ms 91ms
> juju.leases 30ms 13ms 16ms
> juju.txns.log 18ms 3ms 14ms
>
> ns total read write
> local.oplog.rs 218ms 218ms 0ms
> juju.txns 196ms 14ms 182ms
> juju.leases 81ms 36ms 44ms
> juju.txns.log 34ms 5ms 29ms
>
>
>
>
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