Forum Discussion
AlexBCT
Cumulonimbus
CumulonimbusHow useful is SSL mirroring when clustering?
When clustering, persistence mirroring is a no-brainer, and connection mirroring can also be useful under the right circumstances, but how about SSL connection mirroring? (https://support.f5.com/csp/...
Hi, Alex
Bugs apart (let's assume we live in a perfect world for a minute), I always like to activate mirroring when I know traffic is SSL-based, whether the F5 terminates SSL sessions or not.
The idea is precisely what you mentioned - making life easier for endpoints, who don't have to recreate all the SSL sessions in the event of a failover. If you don't have SSL termination, or if you do but re-encrypt traffic for the server-side, "endpoints" means client and server. You may not be worried with performance issues on the client machine, but tipically you want to take that load off your servers, even if it means putting a little extra load on the F5 machines.
About performance on the F5 itself, the only way to know if you are having a big impact is by monitoring. If your system is very underloaded, even when doing mirroring, I would say keep it that way. If you are near any limits (CPU or RAM), disabling mirroring might help if there are a big number of sessions.
/Mike
Kai_Wilke
MVP
MVPHi Alex,
Your "hardly reliable source" might be right, that it could be a used to flatten performance spikes during failovers, but on the other hand introduces new challenges and performance implications. Its an individual tradeoff decission to make based on a specific setup and workload....
Personally I never considered to enable "Connection" or "SSL connection" mirrorring for HTTPS sites. For other services which are more dependant on the underlying TCP channel and TLS connection (e.g. LDAPS) it makes much more sense to enable...
Cheers, Kai