On 10/8/20 9:11 AM, Josip Deanovic wrote: > On 2020-10-08 14:56, Phil Stracchino wrote: >> High availability, fundamentally. I'd honestly prefer to be using >> Percona XtraDB Cluster, but there is no working, maintained ebuild for >> Gentoo Linux — and enterprise customers ARE going to try to use it >> against HA clusters, so we'd better be sure it works. Which it does, >> as >> long as attribute spooling is disabled (and you're not using Director >> 9.6.5). > > Do you have to turn off attribute spooling with 9.6.3 and 9.6.6? > Disabling attribute spooling will inflict noticeable performance > degradation.
Unfortunately, yes, because the attribute spooling code — at least for the MySQL driver — is broken. It caches all of the attribute data in a temporary table until the job is done, then dumps it all into the DB at once, ignoring the configured write batch size. If the job copies more than 128K files, this exceeds Galera 3's hard writeset limit. If it honored the batch size setting, it would be perfectly fine. That said, I probably would not have done the spooling that way in the first place. I would have cached the attribute data in memory until I had $BATCHSIZE records, then written them directly to the DB in a batch. I honestly think this would perform better than saving them all until the end of the job and then ogging the DB with potentially millions of records at once. That is ALWAYS a bad idea. I'd write and offer a patch — in fact I'd overhaul the entire MySQL driver — but I don't know nearly enough C++. -- Phil Stracchino Babylon Communications ph...@caerllewys.net p...@co.ordinate.org Landline: +1.603.293.8485 Mobile: +1.603.998.6958 _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
