Javascript expiry handler

Colleagues,
we're using Couchbase in live production for about 5 years now and are 99% happy.
We have different clusters with different tasks.
One of those is session storage.
We store about 10M of sessions, and update them at 1K requests/second/node.

One of problems we're facing is that we need to do some actions if session is abandoned.
Like destructor.
Generally speaking, to do some thing with a session, when we feel it's time to do that.

Please consider to alter expiration pager ("exp_pager_stime" infrastructure), to... invoke javascript code and pass it key+value and allow it to connect to external sources by TCP/UDP to notify those about a change.

(inspired by view map function; understand 100% that its unrelated)