Ahoi Pavel, On Fri, Nov 15, 2013 at 01:59:49PM -0800, Pavel Ivanov wrote: [snip] > > As an example here's an independent comparison of Galera vs. > > semi-sync performance: > > http://linsenraum.de/erkules/2011/06/momentum-galera.html. > > This is a nice blog post written in German and posted in 2011. And > while Google Translate gave me an idea what post was about it would be > nice to see something more recent and with better description of what > was the actual testing set up.
it is my post and as a fact you are right a newer one would be also nice. As a fact there is one: http://linsenraum.de/erkules/2012/03/galera-als-replikationsersatz.html (Even there is a mistake: missing setting for innodb_flush_log_at_trx_commit=0). There you also get some infos about the used hardware I think Im going to write a new one. Also with newer hardware. And there will be an English version. The basic idea oft the tests is. Not to rely on the 'master'. Thats why I used settings like innodb_flush_log_at_trx_commit=0 and innodb_doublewrite=0 The basic idea is not to rely on any data of a crushed node. Working also in 'cloudenvironments' I prefer to rebuild instead to repair a node. To make it short. * Galera is always faster than Semisync. You can compare it to async repl. It gets his speed out of the parallel applying. * With Galera you have (virtual) synchronous replication. Using Semisync you know nothing. All you can do is monitoring semisync variables. But I doubt it will tell you anything about the 'last' transactions So you got async repl speed with synchronous data \o/ Regards Erkan -- über den grenzen muß die freiheit wohl wolkenlos sein _______________________________________________ Mailing list: https://launchpad.net/~maria-developers Post to : [email protected] Unsubscribe : https://launchpad.net/~maria-developers More help : https://help.launchpad.net/ListHelp
