On Tue, Apr 19, 2016 at 9:06 AM, Adam Young <ayo...@redhat.com> wrote:
> I wonder how much of that is Token caching. In a typical CLI use patter, > a new token is created each time a client is called, with no passing of a > token between services. Using a session can greatly decrease the number of > round trips to Keystone. > Not as much as you think (or hope?). Persistent token caching to disk will help some, at other expenses though. Using --timing on OSC will show how much time the Identity auth round trip cost. I don't have current numbers, the last time I instrumented OSC there were significant load times for some modules, so we went a good distance to lazy-load as much as possible. What Dan sees WRT a persistent client process, though, is a combination of those two things: saving the Python loading and the Keystone round trips. I have (had!) a version of DevStack that put OSC into a subprocess and called it via pipes to do essentially what Dan suggests. It saves some time, at the expense of complexity that may or may not be worth the effort. One thing missing is any sort of transactional control in the I/O with the subprocess, ie, an EOT marker. I planned to add a -0 option (think xargs) to handle that but it's still down a few slots on my priority list. Error handling is another problem, and at this point (for DevStack purposes anyway) I stopped the investigation, concluding that reliability trumped a few seconds saved here. Ultimately, this is one of the two giant nails in the coffin of continuing to persue CLIs in Python. The other is co-installability. (See that current thread on the ML for pain points). Both are easily solved with native-code-generating languages. Go and Rust are at the top of my personal list here... dt
__________________________________________________________________________ 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
