[Buildbot-devel] scheduler questions

[Marnix Klooster]

Stefan Seefeld wrote:

> Brian Warner wrote:
>
>>> On a related note, is there anything I can do to control the level of
>>> concurrency, i.e. the number of processes run in parallel on a given
>>> machine (e.g. slave) ? It would be good to be able to constrain the 
>>> number
>>> of builds executed in parallel on a particular machine, to avoid 
>>> excessive
>>> high loads.
>>
>>
>>
>> We have slave-wide Locks, which can keep the number of processes down 
>> to one
>> per slave. With a little bit of work, these could probably be 
>> enhanced to
>> behave more like multiple-holder semaphores, so you could have two or 
>> three
>> Steps or Builds running at the same time on any given slave.
>
>
> Yes, I think that would be very useful indeed.


I second that.

Practical use case that could be implemented by this mechanism (I 
think): I've got a pool of resources (in this case, for example, 4 
ClearCase views with common derived object storage), and a bunch of 
builds (some 25) for which I don't want to create 25 corresponding views 
(because the storage would be too much).  So when a build starts, I want 
it to take a free ClearCase view from the pool of 4, use it during the 
build, and then free it up again for other builds.

Groetjes,
 <><
Marnix