[pgpool-general: 3066] Re: Failover - new primary selection process?
ishii at postgresql.org
Mon Jul 28 16:20:38 JST 2014
No. Pgpool-II has no idea which server has been running longer.
Pgpool-II has no built-in logic to choose next
to-be-primary-candidate. Which slave node will be promoted next time
is completely depending on your failover script. In general most
people specifies the candidate slave as the master node, which has the
yonguest node number among live slave nodes (%m in failover script).
Example: you have node 0 primary, node 1&2 standby.
1) node 0 is down.
2) node 1 is chosen as the next primary because it's the youngest live
3) node 1 is down.
4) node 2 is chosen as the next primary because it's the youngest live
SRA OSS, Inc. Japan
> Hey jay, thank you for the replay.
> Is this is a formal conclusion? Maybe the oldest is the one with the
> smaller ID ?
> On Sun, Jul 27, 2014 at 2:50 PM, <jayknowsunix at gmail.com> wrote:
>> I run a master with 2 slaves. During a failover, I always see the oldest
>> slave promoted to master. So, the selection is based on the server which
>> has been running longer.
>> Sent from my iPad
>> > On Jul 27, 2014, at 3:48 AM, Guy Meler <melguy at gmail.com> wrote:
>> > Hey :)
>> > In master/slave mode, what is the algorithm for choosing the next
>> available primary backend?
>> > I want to make sure that if primary in site A goes down, than the next
>> available primary is in the same site.
>> > Thank you
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