Lower puppet.lizard's amount of RAM
Chances are that it does not really need 6GB of RAM, since puppet-tails@d79f1e0a.
Before the migration to this new puppet module, our Puppet master needed less than 2.5 GB of RAM. I suspect the only reason we had to bump this (incrementally) up to 6GB of RAM is that all the load from agents happened at the same time.
This is probably not urgent but good to keep in mind next time we need RAM elsewhere on lizard.