> I tested a code change that essentially reverts > https://review.openstack.org/#/c/276861/1/nova/api/metadata/base.py > > In other words, with this change metadata tables are not fetched by > default in API requests. If I understand correctly, metadata is > fetched in separate queries as the instance object is > created. Everything seems to work just fine, and I've considerably > reduced the amount of data fetched from the database, as well as > reduced the average response time of API requests. > > Given how simple it is and the results I'm getting, I don't see any > reason not to patch my clusters with this change. > > Do you guys see any other impact this change could have? Anything that > it could potentially break?
This is probably fine as a bandage fix, but it's not the right one for upstream, IMHO. By doing what you did, you cause two RPC round-trips to fetch the instance and then the metadata every single time the metadata API is hit (not including the cache). By converting the DB load to do the two-step, we still hit the DB twice, but only one RPC round-trip, which will be much more efficient especially at load/scale. --Dan __________________________________________________________________________ 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