> On Jan. 7, 2016, 4:21 p.m., Maxim Khutornenko wrote: > > src/main/java/org/apache/aurora/scheduler/storage/db/DbModule.java, line 126 > > <https://reviews.apache.org/r/42041/diff/1/?file=1186513#file1186513line126> > > > > Are there any perf implications from having it ON by default? Should it > > be a configurable flag instead? > > Zameer Manji wrote: > Good question, I'll run benchmarks and update the testing done. > > John Sirois wrote: > And if there are perf implications, there is always [`SET > QUERY_STATISTICS`](http://www.h2database.com/html/grammar.html?highlight=QUERY_STATISTICS&search=QUERY_STATISTICS#set_query_statistics) > via the /h2console - and maybe that could just be documented as an ad-hoc > option. > > Zameer Manji wrote: > John, using `SET QUERY_STATISTICS` will not persist across failovers and > is not retroactive. This means operators need to run `SET QUERY_STATISTICS` > and wait for data to be collected if they notice the scheduler is slower than > expected. If this option is set when the database is created the data > collected should reflect all operations done by the scheduler and that is > more useful for triaging slow scheduling in large clusters. > > I think providing a flag or enabling it by default (pending results of > benchmarks) are better solutions.
Makes sense. Have you thought about the existing slow query logging and how that evolves with this? Probably fine side-by-side, but maybe confusing and less valuable once the mem store is gone and the db store is all we have. - John ----------------------------------------------------------- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/42041/#review113355 ----------------------------------------------------------- On Jan. 7, 2016, 4:14 p.m., Zameer Manji wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > https://reviews.apache.org/r/42041/ > ----------------------------------------------------------- > > (Updated Jan. 7, 2016, 4:14 p.m.) > > > Review request for Aurora, John Sirois and Maxim Khutornenko. > > > Repository: aurora > > > Description > ------- > > With this enabled operators can visit the H2 console at /h2console and run > queries like `SELECT * FROM INFORMATION_SCHEMA.QUERY_STATISTICS ORDER BY > MAX_EXECUTION_TIME DESC;` to diagnose slow schedulers. > > > Diffs > ----- > > src/main/java/org/apache/aurora/scheduler/storage/db/DbModule.java > e3efbdb80d8b18312bf1589eef883cdeee65b225 > > Diff: https://reviews.apache.org/r/42041/diff/ > > > Testing > ------- > > Ran `SELECT * FROM INFORMATION_SCHEMA.QUERY_STATISTICS ORDER BY > MAX_EXECUTION_TIME DESC;` within vagrant and saw query statistics. > > > Thanks, > > Zameer Manji > >
