On 9/22/21 1:14 PM, Dumitru Ceara wrote: > On 9/16/21 10:15 PM, Ilya Maximets wrote: >> Currently, even if one reference added to the set of strong references >> or removed from it, ovsdb-server will walk through the whole set and >> re-count references to other rows. These referenced rows will also be >> added to the transaction in order to re-count their references. >> >> For example, every time Logical Switch Port added to a Logical Switch, >> OVN Northbound database server will walk through all ports of this >> Logical Switch, clone their rows, and re-count references. This is >> not very efficient. Instead, it can only increase reference counters >> for added references and reduce for removed ones. In many cases this >> will be only one row affected in the Logical_Switch_Port table. >> >> Introducing new function that generates a diff of two datum objects, >> but stores added and removed atoms separately, so they can be used >> to increase or decrease row reference counters accordingly. >> >> This change allows to perform several times more transactions that >> adds or removes strong references to/from sets per second, because >> ovsdb-server no longer clones and re-counts rows that are irrelevant >> to current transaction. >> >> Signed-off-by: Ilya Maximets <i.maxim...@ovn.org> >> --- > > Hi Ilya, > > I've been trying this patch out and with a micro benchmark that does: > > - create X rows in table A > - create Y rows in table B (non-root) and reference the rows in table B
Sorry, I meant create Y rows for each row in X here, essentially X * Y rows in table B. > from exactly one row in table A, uniformly distributed, one new row per > transaction. > - remove the references to all rows in B from table A, one removal per > transaction. > > I got the following results: > > X=120, Y=250, w/o patch: > - ovsdb-server CPU 10.4%, 27 sec > > X=120, Y=250, w/ patch (gain ~33%): > - ovsdb-server CPU 6.9%, 18 sec > > X=1, Y=30000, w/o patch: > - ovsdb-server CPU goes up to 100% and I stopped it after ~15 min while > it was still executing the "create" part of the test. > > X=1, Y=30000, w/ patch: > - ovsdb-server CPU 43.2%, 175 sec > > I was wondering if it makes sense to factor out the common part of > ovsdb_datum_added_removed() and ovsdb_datum_diff(). It seems to me that > ovsdb_datum_diff(diff, old, new, type) is almost the same as > ovsdb_datum_added_removed(diff, diff, old, new, type), we just need to > handle the non-composite types separately and deal with the case when > 'added' == 'new' if we detect a value changing for a given key. > > In any case, the code looks OK to me in the current form too, so: > > Acked-by: Dumitru Ceara <dce...@redhat.com> > > Regards, > Dumitru > _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev
