Hello Pavel,

On Thu, Aug 25, 2016 at 2:21 PM, Pavel Raiskup <praiskup@redhat.com> wrote:
On Thursday, August 18, 2016 1:30:57 PM CEST Michal Novotny wrote:
> 2) Waiting-queue logic has been rewritten. I believe there will be not much
> of a perceived performance improvement but we managed to cut the relevant
> code length almost by half and simplify some bits.

Hms, thanks for the info.  That commit 1c51da66151df0e1add7ca877568d16584793bef
removed a lot of code in scheduler, which was a debugged with care and took
(really) non-trival efforts to get it working right ...

What exactly changed, is there link for patch review to simplify reading, to
follow reasoning behind?
Does that mean that we no longer preallocate workers (looks like 'max_workers'
backend parameter disappeared)?  Where is the queue mainained now (python retask
is missing)?

the queue is now maintained only in frontend and backend is served with tasks one by
one. Workers are being spawned "on demand". Their maximum count is determined by
configured maximum number of virtual machines that can be allocated. The code emerged as
a reaction to the problem described in https://bugzilla.redhat.com/show_bug.cgi?id=1344805.