Comment 1 for bug 1454661

Hi,

Not purging the presence collections leads to mongodb performance issues that I believe are one of the causes of the high CPU usage by jujud and mongod, leading to overall performance issues.

We have a juju 2.1.1 controller running about 40 models, and a lot of time is spent reading the presence.beings collections : https://paste.ubuntu.com/24145949/

Some queries are returning over 20k items, and over 3MB of data ! https://paste.ubuntu.com/24145956/

The distribution by of items per model is the following : https://paste.ubuntu.com/24145961/

I believe fixing this will make juju2 more stable (and I don't really understand why this was triaged as "Won't fix").

Also, the presence.beings collection doesn't have any index by default (on our database, we have added one as recommended by axw).

Thanks !