PCP is a capable and expansive framework for system performance and analysis.

http://www.pcp.io/

Marius and Andreas have done some really nice work using PCP for metrics and loading of archived metric data.

However in order to make use if it, attention to and grooming of PCP is necessary. Details below.

A bunch of us discussed this yesterday, and came to the conclusion that having PCP required by default goes against the principles [1] of Cockpit. In particular:

* Cockpit should work out of the box. In particular the graphs should work out of the box. * Installing Cockpit should not fundamentally alter the server, via dependencies, additional running services ... and the footprint should be small.

Cockpit isn't perfect on the latter point yet. We do drag in runtime dependencies that should be optional (such as accountsservice and realmd), but with each release we're removing those. The end goal is that Cockpit is a UI for the OS, and the software that comes with it.

Yes, I do realize this is a fuzzy goal, but never the less, we want to be heading in the right direction.

Outstanding PCP issues:

https://bugzilla.redhat.com/show_bug.cgi?id=1185740 https://trello.com/c/lpbZHZsG/110-pcp-completely-solid-out-of-the-box

None of these issues are unsolvable. In fact during brainstorming and discussion with Frank and the PCP team there have been possible solutions to each of the issues.

Once the outstanding issues have been resolved, it would be probably be appropriate for Cockpit to have a default dependency on pcp-libs and the linux PMDA.

But it is premature for us to have a PCP dependency out of the box, and doubly so when that dependency is on the entire PCP stack.

So we're doing a bit of work to make PCP optional:

https://trello.com/c/ub3zQOUE/129-pcp-optional-dependency https://github.com/cockpit-project/cockpit/pull/1856

On Fedora 22, folks who want to use PCP and view archived data in the graphs, or folks who already have PCP on their server, will be able to install the optional cockpit-pcp sub-package.

Stef

[1] http://stef.thewalter.net/ideals-of-cockpit.html