On Wed, Dec 7, 2016 at 9:57 AM, Roy Golan <rgo...@redhat.com> wrote: > Hi all, > > This is a discussion on the RFE[1] to provide a tool to perform full vacuum > on our DBs. > > First if you are not familiar with vacuum please read this [2] > > # Backgroud > ovirt 'engine' DB have several busy table with 2 differnt usage patten. One > is audit_log and the others are the 'v*_statistics' tables and the > difference between them is mostly inserts vs mostly hot updates. > Tables with tons of updates creates garbage or 'dead' records that should be > removed, and for this postgres have the aforementioned autovacuum cleaner. > It will make the db reuse its already allocated space to perform future > updates/inserts and so on. > Autovacuum is essential for a db to function optimally and tweaking it is > out of the scope of the feature. > > Full vacuum is designed to reclaim the disk space and reset the table > statistics. It is a heavy maintenance task, it takes an exclusive lock on > the table and may take seconds to minutes. In some situations it is > effectively a downtime due to the long table lock and should not be running > when the engine is running. > > # Critiria > Provide a way to reclaim disk space claimed by the garbage created over time > by the engine db and dwh.
What about not storing this data in db? Do we need it all the time or just for some amount of time? > > # Usage > Either use it as part of the upgrade procedure (after all dbscipts > execution) > or just provide the tool and admin will run in on demand > - engine db credentials read from /etc/ovirt-engine/engine.conf.d/ > - invocation: > ``` > tool: [dbname(default engine)] [table: (default all)] > ``` > - if we invoke it on upgrade than an installation plugin should be added to > invoke with default, no interaction > - since VACUUM ANALYZE is consider a recommended maintenance task we can to > it by default and ask the user for FULL. > - remote db is supported as well, doesn't have to be local > > # Questions > - Will remote dwh have the credentials under > /etc/ovirt-engine/engine.conf.d? > - Should AAA schema be taken into account as well? > > Please review, thanks > Roy > > [1] https://bugzilla.redhat.com/show_bug.cgi?id=1388430 > [2] > https://www.postgresql.org/docs/9.2/static/runtime-config-autovacuum.html > [3] https://www.postgresql.org/docs/devel/static/sql-vacuum.html > > _______________________________________________ > Users mailing list > Users@ovirt.org > http://lists.ovirt.org/mailman/listinfo/users > _______________________________________________ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
