mosquitto-users team mailing list archive

[Roger Light <roger@xxxxxxxxxx>]

Hi Mike,

> Sharon, the problem that I can already tell you that will arise with SSL is
> memory usage.  I forget the exact numbers but calling the consumption
> noticeable would be an understatement.

Openssl >=1.0 allows SSL compression to be disabled which reputedly
saves significant amounts of memory. I haven't tested it myself yet,
but plan on doing so for 1.1. This link
http://journal.paul.querna.org/articles/2011/04/05/openssl-memory-use/
reckons going from ~500kB to ~75kB per connection by disabling
compression.

Using SSL_MODE_RELEASE_BUFFERS can likewise save up to 34kB per idle
SSL session as well, apparently.

Cheers,

Roger