From where would you propose measuring these data points? Obviously
network latency will have a great impact on some of the metrics and a consistent location would help to define the pass/fail of each test. I do think another benchmark Ops "features" would be a set of latency-to-datacenter values, but I know that is a much harder taks. Thanks for putting this together.
On Thu, Mar 21, 2013 at 6:40 PM, Asher Feldman afeldman@wikimedia.orgwrote:
I'd like to push for a codified set of minimum performance standards that new mediawiki features must meet before they can be deployed to larger wikimedia sites such as English Wikipedia, or be considered complete.
These would look like (numbers pulled out of a hat, not actual suggestions):
- p999 (long tail) full page request latency of 2000ms
- p99 page request latency of 800ms
- p90 page request latency of 150ms
- p99 banner request latency of 80ms
- p90 banner request latency of 40ms
- p99 db query latency of 250ms
- p90 db query latency of 50ms
- 1000 write requests/sec (if applicable; writes operations must be free
from concurrency issues)
- guidelines about degrading gracefully
- specific limits on total resource consumption across the stack per
request
- etc..
Right now, varying amounts of effort are made to highlight potential performance bottlenecks in code review, and engineers are encouraged to profile and optimize their own code. But beyond "is the site still up for everyone / are users complaining on the village pump / am I ranting in irc", we've offered no guidelines as to what sort of request latency is reasonable or acceptable. If a new feature (like aftv5, or flow) turns out not to meet perf standards after deployment, that would be a high priority bug and the feature may be disabled depending on the impact, or if not addressed in a reasonable time frame. Obviously standards like this can't be applied to certain existing parts of mediawiki, but systems other than the parser or preprocessor that don't meet new standards should at least be prioritized for improvement.
Thoughts?
Asher _______________________________________________ Wikitech-l mailing list Wikitech-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikitech-l