Vladimir, As I understand "striped pool" is a array of single-threaded pools. Do you have an understanding why throughput increased up to 40%? It looks like it is due to every thread has its own task queue.
As far as I know, there is ForkJoinPool in JDK, FJP implements ExecutorService interface, has striped tasks queue, has task-stealing mechanics. Can we run Ignite performance tests b\w using "striped pool" and FJP? On Fri, Dec 16, 2016 at 11:17 AM, Vladimir Ozerov <voze...@gridgain.com> wrote: > Folks, > Can we move all discussions aside of pool config to separate threads, > please? :-) > > Dima, > I heard your concern about configuration complexity. But I do not see any > problem at all. Whether to use striped pool or not is a matter of > fine-grained tuning. We will set sensible defaults (i.e. enabled striped > pool), so 99% of users will never know that a concept of "stiped pool" even > exists. > > Striped and non-striped approaches have their own pros and cons. > > Striped: > + Better overall throughput (up to +40% compared to non-striped); > - Less predictable latency - user can have bad numbers even on moderate > load (e.g. consider updates on a large affinity co-located object graph). > Benchmarks demonstrate this clearly. > - Higher memory footprint, because in striped mode we pre-start all the > threads. On high-end machines it may end up in wasting of hundrends of > megabytes of RAM. > - As a result of previous point, it is not well-suited for clients, which > may require small memory footprint and low startup time. > > Non-striped: > - Worse throughput due to very high contention on BlockingQueue. > + No waste on idle threads. > > I would propose the following final design for this: > > - Introduce *"boolean systemThreadPoolStriped"* property; > - Set it to *"true"* for servers by default; > - Set it to *"false"* for clients by default. > > Yakov, > I still do not get your point about (system + public) pools approach. > > Vladimir. > > On Fri, Dec 16, 2016 at 9:29 AM, Yakov Zhdanov <yzhda...@apache.org> > wrote: > > > >In my view, we should hide most of such configuration intricacies from > > users, > > and select an appropriate thread pool for each task ourselves. Will this > be > > possible? > > > > We already do this. We take decision internally on where to route the > > request. > > > > SoE, my answers below. > > > > >How did the striped pool show itself for transactional updates that > > involve 2 phase commit? Any benefits or degradation? > > > > Even better than for atomic - up to ~50% improvement. > > > > >Here we should decide what’s more important for us - throughout or > > latency. If to execute SQL queries in the striped pool using multiple > > partitioned threads then, for sure, it will affect latency of other > > operations that are sitting in the queue waiting for their time to be > > processed but, on the other hand, the overall throughput of the platform > > should be improved because the operations will be less halted all the > time > > by synchronization needs. > > > > >VoltDB decided to go for with the throughput while our current > > architecture is mostly latency based. > > > > What do you mean by "using several partition threads"? I am pretty sure > > that if we do as you suggest we will have degradation here instead of > > boost: > > > > sql-query-put > > after: 77,344.83 > > before: 53,578.78 > > delta: 30.73% > > > > sql-query-put-offheap > > after 32,212.30 > > before 25,322.43 > > delta 21.39% > > > > --Yakov > -- С уважением, Машенков Андрей Владимирович Тел. +7-921-932-61-82 Best regards, Andrey V. Mashenkov Cerr: +7-921-932-61-82
