Hi Mark, thanks for this interesting reading. I will also want to have a look at how much MariaDB is affected by reported regressions and if there are easy ways to workaround them.
Recently, when I ran single thread benchmarks I observed similar results, that is parser and optimizer were top CPU time consumers (as well as bus traffic producers). Thanks, Sergey On Mon, Jan 20, 2014 at 09:32:41AM -0800, MARK CALLAGHAN wrote: > My analysis was based on benchmarks and described in a few blog posts. This > is interesting for a few reasons. > 1) replication is single-threaded at least for a few more years. Eventually > we will all have the Kristian-inspired idea of getting parallel replication > apply even when there is only one database shard and that helps some. But > there are always some workloads that really are single threaded on the > master and during replication apply. > 2) fast storage means that IO-bound workloads might be able to get 100,000+ > IOPs on a commodity server. So even when IO-bound we need much higher > throughput in the past > 3) At least with public-facing information Oracle doesn't write about this > topic. Their performance focus is high concurrency. > 4) RAM per host is much larger so more workloads are not IO bound and > expect high throughput > > I don't think a complex workload is needed to show the problem. sysbench > and dbt might be sufficient. linkbench should also be useful to MariaDB. > > http://mysqlha.blogspot.com/2013/09/mysql-41-forever.html > http://mysqlha.blogspot.com/2013/09/single-threaded-connect-performance.html > http://mysqlha.blogspot.com/2013/09/mysql-572-single-threaded-performance.html > http://mysqlha.blogspot.com/2013/05/mysql-56-single-threaded-performance.html > http://mysqlha.blogspot.com/2013/05/mysql-56-versus-40-for-read-only.html > http://mysqlha.blogspot.com/2013/04/mysql-56-single-thread-update-only.html > http://mysqlha.blogspot.com/2013/03/mysql-56-single-threaded-read-only.html > > > On Mon, Jan 20, 2014 at 8:18 AM, Sergey Vojtovich <s...@mariadb.org> wrote: > > > Hi Mark, > > > > we identified a few single-thread performance issues during the Barcelona > > meeting. Monty should have them fixed in his private tree. Fixes are quite > > generic and should improve performance almost in all cases. An exception is > > bottlenecks specific to certain use cases. > > > > Could you send me any relevant information my way if you have it around? > > > > Thanks, > > Sergey > > > > On Mon, Jan 20, 2014 at 08:00:45AM -0800, MARK CALLAGHAN wrote: > > > Are there other goals for single-thread performance regressions? There > > are > > > many that have nothing to do with replication code although almost every > > > single-threaded replication hurts replication. > > > > > > > > > On Mon, Jan 20, 2014 at 2:54 AM, Axel Schwenke <a...@askmonty.org> > > wrote: > > > > > > > Hi, > > > > > > > > for those of you who didn't attend the Barcelona meeting last week, > > here > > > > are > > > > the plans for next steps in benchmarking: > > > > > > > > 1. top priority is automatic running of DBT3 for each new release of > > > > MariaDB-10.0 and MySQL-5.6. Probably also for MariaDB-5.5. I'll send > > out > > > > another mail to pinpoint DBT3 conditions (i.e. which table statistics > > to > > > > use > > > > etc.) > > > > > > > > 2. multithreaded replication slave is now in a condition that it can > > and > > > > should be benchmarked > > > > > > > > 3. the problem pointed out by Yoshinori in > > > > > > > > > > http://yoshinorimatsunobu.blogspot.de/2013/12/single-thread-performance-regression-in.html > > > > must be checked for MariaDB. Monty announced that he will commit a > > patch > > > > this week that should help with that problem. > > > > > > > > 4. for the NUMA scalability problem, Kristian will try to find the > > > > definitive reason with profiling tools. Besides that ad-hoc testing of > > new > > > > patches from Svoj continues as before. > > > > > > > > 5. Galera benchmarking will be done by the Galera team for now. > > > > > > > > > > > > XL > > > > > > > > _______________________________________________ > > > > Mailing list: https://launchpad.net/~maria-developers > > > > Post to : maria-developers@lists.launchpad.net > > > > Unsubscribe : https://launchpad.net/~maria-developers > > > > More help : https://help.launchpad.net/ListHelp > > > > > > > > > > > > > > > > -- > > > Mark Callaghan > > > mdcal...@gmail.com > > > > > _______________________________________________ > > > Mailing list: https://launchpad.net/~maria-developers > > > Post to : maria-developers@lists.launchpad.net > > > Unsubscribe : https://launchpad.net/~maria-developers > > > More help : https://help.launchpad.net/ListHelp > > > > > > > -- > Mark Callaghan > mdcal...@gmail.com _______________________________________________ Mailing list: https://launchpad.net/~maria-developers Post to : maria-developers@lists.launchpad.net Unsubscribe : https://launchpad.net/~maria-developers More help : https://help.launchpad.net/ListHelp
