Ted, To clarify, I'm talking about a hypothetical bugfix that impacted performance, not to imply that I know of a specific such change.
I've seen it often enough before that performance is blazing fast at the expense of accuracy and people are surprised when correctness takes longer. Mike On Tue, Nov 28, 2017 at 1:01 PM, Ted Yu <yuzhih...@gmail.com> wrote: > Mike: > Which JIRA was the important bug-fix ? > > Thanks > > On Tue, Nov 28, 2017 at 9:16 AM, Mike Drob <md...@apache.org> wrote: > > > Eshcar - do you have time to try the other alpha releases and see where > > exactly we introduced the regressions? > > > > Also, I'm worried that the performance regression may be related to an > > important bug-fix, where before we may have had fast writes but also > risked > > incorrect behavior somehow. > > > > Mike > > > > On Tue, Nov 28, 2017 at 2:48 AM, Eshcar Hillel <esh...@oath.com.invalid> > > wrote: > > > > > I agree, so will wait till we focus on performance. > > > Just one more update, I also ran the same experiment (write-only) with > > > banch-2 beta-1.Here is a summary of the throughput I see in each > > tag/branch: > > > ------------------------------- | BASIC | NONE | > > > -------------------------------2-alpha-1| 110K | 80K | > > > 2-beta-1 | 81K | 62K | > > > master | 60K | 55K |------------------------------- > > > This means there are multiple sources for the regression. > > > > > > Thanks > > > > > > On Saturday, November 25, 2017, 7:44:01 AM GMT+2, 张铎(Duo Zhang) < > > > palomino...@gmail.com> wrote: > > > > > > I think first we need a release plan on when we will begin to focus on > > the > > > performance issue? > > > > > > I do not think it is a good time to focus on performance issue now as > we > > > haven’t stabilized our build yet. The performance regression may come > > back > > > again after some bug fixes and maybe we use a wrong way to increase > > > performance and finally we find that it is just a bug... > > > > > > Of course I do not mean we can not do any performance related issues > now, > > > for example, HBASE-19338 is a good catch and can be fixed right now. > > > > > > And also, for AsyncFSWAL and in memory compaction, we need to consider > > the > > > performance right now as they are born for performance, but let’s focus > > on > > > the comparison to other policies, not a previous release so we can find > > the > > > correct things to fix. > > > > > > Of course, if there is a big performance downgrading comparing to the > > > previous release and we find it then we should tell others, just like > > this > > > email. An earlier notification is always welcomed. > > > > > > Thanks. > > > > > > Stack <st...@duboce.net>于2017年11月25日 周六13:22写道： > > > > > > > On Thu, Nov 23, 2017 at 7:35 AM, Eshcar Hillel > <esh...@oath.com.invalid > > > > > > > wrote: > > > > > > > > > Happy Thanksgiving all, > > > > > > > > > > > > > And to you Eshcar. > > > > > > > > > > > > > > > > > In recent benchmarks I ran in HBASE-18294 I discovered major > > > performance > > > > > degradation of master code w.r.t 2-alpha-1 code.I am running > > write-only > > > > > workload (similar to the one reported in HBASE-16417). I am using > the > > > > same > > > > > hardware and same configuration settings (specifically, I testes > both > > > > basic > > > > > memstore compaction with optimal parameters, and no memsore > > > > > compaction).While in 2-alpha-1 code I see throughput of ~110Kops > for > > > > basic > > > > > compaction and ~80Kops for no compaction, in the master code I get > > only > > > > > 60Kops and 55Kops, respectively. *This is almost 50% reduction in > > > > > performance*. > > > > > (1) Did anyone else noticed such degradation?(2) Do we have any > > > > systematic > > > > > automatic/semi-automatic method to track the sources of this > > > performance > > > > > issue? > > > > > Thanks,Eshcar > > > > > > > > > > > > > > > > > On #1, no. I've not done perf compare. I wonder if later alpha > versions > > > > include the regression (I'll have to check and see). > > > > > > > > On #2, again no. I intend to do a bit of perf tuning and compare > before > > > > release. > > > > > > > > If you don't file an issue, I will do so later for myself as a task > to > > > > compare at least to alpha-1. > > > > > > > > Thanks Eshcar, > > > > > > > > St.Ack > > > > > > > > > >
