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 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