Dump info about ssl.cachesize usage

[rfrail3]

What should haproxy do differently? Which functionality do you think we should add?

Via configuration file you can set the ssl.cachesize, but it isn't possible to know the current usage.
It would be nice to have a new line on "show info" with that information, for example, in combination with the current two SslCahe entries:

SslCacheLookups: 12669910
SslCacheMisses: 9994550
SslCacheUsage: 15766

Also commented in https://discourse.haproxy.org/t/check-usage-of-ssl-cachesize/6337

What are you trying to do?

Easily know the current ssl cache usage.

Output of haproxy -vv and uname -a

# haproxy -vv
HA-Proxy version 2.2.10-6a09215 2021/03/03 - https://haproxy.org/

[rlebreton]

The cache entries are not removed from the cache until we try to insert a new entry and the cache is full. So the cache is bound to be "full" after some time and it won't ever be emptied. This notion of cache usage would not mean much after the cache is full, it would almost always give a value close to your tune.ssl.cachesize.