Hi Avinash -
(1) Is it possible to increase the number of observers in the cluster
Not really - you can use the same rolling-restart technique that is often
mentioned on this list for adding servers to the ensemble, but you can't add
them and expect that ZK will auto-find them.
> (2) How many observers can I add given that I will seldom write into the
> cluster but will have a lot of reads coming into the system? Can I run a
> cluster with say 100 observers?
This will be possible, but there is some overhead in communicating with
observers as well as normal voting followers. However, given that writes are
rare, perhaps this kind of overhead would be acceptable?
> Any insight would be very helpful.