SSL performance optimization with cache

[Maxim Dounin]

Hello!

On Thu, Dec 13, 2012 at 09:45:19PM -0500, justin wrote:

> Hello,
> 
> I am optimizing our install of nginx for SSL performance, since our SaaS app
> is served exclusively over https. I have the following SSL performance
> directives:
> 
>     ssl_session_cache shared:SSL_CACHE:4m;
>     ssl_session_timeout 5m;
> 
> My question is, what is the downfall, if any, of setting the timeout to like
> 720m which is 12 hours. Seems like caching longer would be better. Or, is
> there a security risk of caching for such a long time?

You may consider RFC5246, which suggests an upper limit of 24h:

http://tools.ietf.org/html/rfc5246#appendix-F.1.4

-- 
Maxim Dounin
http://nginx.com/support.html