On 1/11/2021 11:25 AM, Walter Underwood wrote:
There are all sorts of problems with the primary/secondary approach. How do you
know
the secondary is working? How do you deal with cold caches on the secondary
when it
suddenly gets lots of load?
Instead, size the cluster with the number of hosts you need, then add one. Send
traffic
to all of them. If any of them goes down, you have the capacity to handle the
traffic.
This is called “N+1 provisioning”.
Where do you send your solr queries? If you have an http server at an ip
address that answers them, that's a single point of failure unless you
put it on a heartbet'ed cluster ip. (I tend to prefer ucarp to pacemaker
for that as the latter is bloated and too cumbersome for simple
active/passive setups, but that's OT.)
Dima
