Max count is one way (vague I agree), before confirming I will ask the application owner to have a look on data in tables as well.
Regards On Tue, Apr 10, 2018, 17:55 Adrian Klaver <adrian.kla...@aklaver.com> wrote: > On 04/10/2018 09:47 AM, Vikas Sharma wrote: > > Thanks Adrian and Edison, I also think so. At the moment I have 2 > > masters, as soon as slave is promoted to master it starts its own > > timeline and application might have added data to either of them or > > both, only way to find out correct master now is the instance with max > > count of data in tables which could incur data loss as well. Correct me > > if wrong please? > > Not sure max count is necessarily a valid indicator: > > 1) What if there was a legitimate large delete process? > > 2) The application/end users where looking at two different views of the > data at different points in time. Just because the count is higher does > not mean the data is actually valid. > > > > > Thanks and Regards > > Vikas > > > > On Tue, Apr 10, 2018, 17:29 Adrian Klaver <adrian.kla...@aklaver.com > > <mailto:adrian.kla...@aklaver.com>> wrote: > > > > On 04/10/2018 08:04 AM, Vikas Sharma wrote: > > > Hi Adrian, > > > > > > This can be a good example: Application server e.g. tomcat having > two > > > entries to connect to databases, one for master and 2nd for Slave > > > (ideally used when slave becomes master). If application is not > > able to > > > connect to first, it will try to connect to 2nd. > > > > So the application server had a way of seeing the new master(old > slave), > > in spite of the network glitch, that the original master database > > did not? > > > > If so and it was distributing data between the two masters on an > unknown > > schedule, then as Edison pointed out in another post, you really > have a > > split brain issue. Each master would have it's own view of the data > and > > latest update would really only be relevant for that master. > > > > > > > > Regards > > > Vikas > > > > > > On 10 April 2018 at 15:26, Adrian Klaver > > <adrian.kla...@aklaver.com <mailto:adrian.kla...@aklaver.com> > > > <mailto:adrian.kla...@aklaver.com > > <mailto:adrian.kla...@aklaver.com>>> wrote: > > > > > > On 04/10/2018 06:50 AM, Vikas Sharma wrote: > > > > > > Hi, > > > > > > We have postgresql 9.5 with streaming > > replication(Master-slave) > > > and automatic failover. Due to network glitch we are in > > > master-master situation for quite some time. Please, > > could you > > > advise best way to confirm which node is latest in terms > of > > > updates to the postgres databases. > > > > > > > > > It might help to know how the two masters received data when > they > > > where operating independently. > > > > > > > > > Regards > > > Vikas Sharma > > > > > > > > > > > > -- > > > Adrian Klaver > > > adrian.kla...@aklaver.com <mailto:adrian.kla...@aklaver.com> > > <mailto:adrian.kla...@aklaver.com <mailto:adrian.kla...@aklaver.com > >> > > > > > > > > > > > > -- > > Adrian Klaver > > adrian.kla...@aklaver.com <mailto:adrian.kla...@aklaver.com> > > > > > -- > Adrian Klaver > adrian.kla...@aklaver.com >
