On Wed, Jan 28, 2015, at 07:57 PM, Johannes Erdfelt wrote: > On Wed, Jan 28, 2015, Vishvananda Ishaya <vishvana...@gmail.com> wrote: > > On Jan 28, 2015, at 4:03 PM, Doug Hellmann <d...@doughellmann.com> wrote: > > > I hope someone who was around at the time will chime in with more detail > > > about why green threads were deemed better than regular threads, and I > > > look forward to seeing your analysis of a change. There is already a > > > thread-based executor in oslo.messaging, which *should* be usable in the > > > applications when you remove eventlet. > > > > Threading was never really considered. The initial version tried to get a > > working api server up as quickly as possible and it used tonado. This was > > quickly replaced with twisted since tornado was really new at the time and > > had bugs. We then switched to eventlet when swift joined the party so we > > didn’t have multiple concurrency stacks. > > > > By the time someone came up with the idea of using different concurrency > > models for the api server and the backend services, we were already pretty > > far down the greenthread path. > > Not sure if it helps more than this explanation, but there was a > blueprint and accompanying wiki page that explains the move from twisted > to eventlet: > > https://blueprints.launchpad.net/nova/+spec/unified-service-architecture > > https://wiki.openstack.org/wiki/UnifiedServiceArchitecture
Thanks Vish & Johannes, that's good background. There are a lot of factors to consider, and having a full picture of the history of how we got to where we are will help us make informed decisions about any proposed changes. Doug > > JE > > > __________________________________________________________________________ > OpenStack Development Mailing List (not for usage questions) > Unsubscribe: > openstack-dev-requ...@lists.openstack.org?subject:unsubscribe > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev __________________________________________________________________________ OpenStack Development Mailing List (not for usage questions) Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev