Re: committing performance patches without performance numbers

2017-03-10 Thread Josh McKenzie
The elephant in the room to me is what Ariel said: > > What about all the commits that don't intend to have a performance impact > but do? On top of that, it's all well and good to microbench the change you make in a vacuum but what happens when the resource usage implications of that change

Re: committing performance patches without performance numbers

2017-03-09 Thread Ariel Weisberg
Hi, I should clarify. Should in the sense of it was fine for the process we had at the time (ugh!) but it's not what we should do in the future. Ariel On Thu, Mar 9, 2017, at 04:55 PM, Ariel Weisberg wrote: > Hi, > > I agree that patch could have used it and it was amenable to >

Re: committing performance patches without performance numbers

2017-03-09 Thread Ariel Weisberg
Hi, I agree that patch could have used it and it was amenable to micro-benchmarking. Just to be pedantic about process which is something I approve of to the chagrin of so many. On a completely related note that change also randomly boxes a boolean. Ariel On Thu, Mar 9, 2017, at 03:45 PM,

Re: committing performance patches without performance numbers

2017-03-09 Thread Jonathan Haddad
I don't expect everyone to run a 500 node cluster off to the side to test their patches, but at least some indication that the contributor started Cassandra on their laptop would be a good sign. The JIRA I referenced was an optimization around List, Set and Map serialization. Would it really

Re: committing performance patches without performance numbers

2017-03-09 Thread Ariel Weisberg
Hi, I think there are issues around the availability of hardware sufficient to demonstrate the performance concerns under test. It's an open source project without centralized infrastructure. A lot of performance contributions come from people running C* in production. They are already running

Re: committing performance patches without performance numbers

2017-03-09 Thread DuyHai Doan
After looking at the patch, my thoughts (beware, it's getting very technical): Original code: -t = new ListType(elements, isMultiCell); -ListType t2 = internMap.putIfAbsent(elements, t); -t = (t2 == null) ? t : t2; Optimized code: +t =

Re: committing performance patches without performance numbers

2017-03-09 Thread Jeff Jirsa
Agree. Anything that's meant to increase performance should demonstrate it actually does that. We have microbench available in recent versions - writing a new microbenchmark isn't all that onerous. Would be great if we had perf tests included in the normal testall/dtest workflow for ALL patches so