On Sat, Jan 11, 2014 at 01:29:23PM +0530, Amit Kapila wrote: > Okay, this is one way of providing this new mode, others could be: > > a. > Have just one GUC sync_standalone_mode = true|false and make > this as PGC_POSTMASTER parameter, so that user is only > allowed to set this mode at startup. Even if we don't want it as > Postmaster parameter, we can mention to users that they can > change this parameter only before server reaches current situation. > I understand that without any alarm or some other way, it is difficult > for user to know and change it, but I think in that case he should > set it before server startup. > > b. > On above lines, instead of boolean parameter, provide a parameter > similar to current one such as available_synchronous_standby_names, > setting of this should follow what I said in point a. The benefit in this > as compare to 'a' is that it appears to be more like what we currently have. > > I think if we try to solve this problem by providing a way so that user > can change it at runtime or when the problem actually occurred, it can > make the UI more complex and difficult for us to provide a way so that > user can be alerted on such situation. We can keep our options open > so that if tomorrow, we can find any reasonable way, then we can > provide it to user a mechanism for changing this at runtime, but I don't > think it is stopping us from providing a way with which user can get the > benefit of this mode by providing start time parameter.
I am not sure how this would work. Right now we wait for one of the synchronous_standby_names servers to verify the writes. We need some way of telling the system how long to wait before continuing in degraded mode. Without a timeout and admin notification, it doesn't seem much better than our async mode, which is what many people were complaining about. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + Everyone has their own god. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
