[Buildbot-devel] slave level locks

[Stefan Seefeld]

Timothee Besset wrote:

> To put things in perspective there are a number of threads on the list
> about load-balanced slaves, multiple buildbot instances, etc. [1]
> 
> I suppose such a thing could be done by introducing a new type of lock
> that connects to a seperate twisted daemon for each slave machine. It
> would hold and release the locks for instance only allowing one build at
> a time, or with options to monitor the CPU load and various other things?

I'm not sure how these two things (locks and CPU load monitoring) fit
together. While using a lock sounds like the simplest thing to implement,
its usability is fairly restrictive: it requires everybody to respect the
lock.
However, build hosts may run more than just build slaves, so looking
at the current load is the only reliable means to figure out whether
to add another process.

Another question, then, is how to react to high loads. Using locks
suggest to simply serialize access to the machine, i.e. to queue builders.
However, in a build farm multiple equivalent machines may be available,
so a real dispatcher is needed that can send build requests to one among
many hosts.

Brian, any ideas on this ? Have you started any work on this ? Is there
anything to be done to help ?

Regards,
		Stefan

-- 

      ...ich hab' noch einen Koffer in Berlin...