Maxim,

Thanks for the reply, so if the oldest cache entries are automatically purged why am I seeing:

ngx_slab_alloc() failed: no memory in SSL session shared cache "SSL_CACHE"

Logged thousands upon thousands of times in my error log? Was this because even though at that time my expiration was 5m, the cache was full, and it couldn't purge any cache entries because none were expired?

If this is the case, I recommend changing the message from critical error to a notice. Basically, just means that SSL connections could not use cache, they were not failing, just slower. Probably shouldn't be a critical error right?