On Wed, Mar 21, 2012 at 04:43:36PM +0000, Guido Trotter wrote: > On Wed, Mar 21, 2012 at 4:39 PM, Iustin Pop <[email protected]> wrote: > > On Wed, Mar 21, 2012 at 05:38:15PM +0100, Bernardo Dal Seno wrote: > >> On Wed, Mar 21, 2012 at 16:59, Michael Hanselmann <[email protected]> > >> wrote: > >> > Instead of acquiring the BGL in exclusive mode (which blocks all other > >> > operations), we acquire all node and instance locks in shared mode > >> > before verifying the configuration. > >> > >> Actually, also group locks are acquired. > > > > Can you guys describe what relation this patch has to the previous one? > > What was the result of the offline discussion? > > > > While the previous one fixes the fact that queries currently acquire > no locks *except* the BGL (which is good because we already had given > up on locks on queries and the BGL was an exception, and still the > only "potential" problems are on node-add and such, with that change) > it's still good for cluster verify not to acquire the BGL and conflict > with other jobs which could go on at the same time, especially if they > are read only. In general we shouldn't have added a new LU requiring > the BGL, and went in the opposite direction (of removing the BGL if > possible) so this needed to happen anyway.
So the conclusion was to: - keep queries not acquiring the BGL at all (prev patch) - fix c-v to not use exclusive BGL Correct? thanks, iustin
