Forum Discussion
Hamish_Marson_3
Nimbostratus
NimbostratusLimiting Sessions?
Has anyone implemented an iRule that limits the number of sessions to a particular virtual server?
Failing that... Does anyone know if it's possible to access the session persistence table from an iRule? (e.g. to count the number of entries in it & redirect to a busy page if there's too many already).
[I looked at extending the iRule that does the limits on connectsion per client, but the session limits need some sort of timeout on the session array... And I'm not sure how (Or even if it were possible) to code a background task that would track & expire inactive sessions...
TIA
Hamish
hoolioCirrostratus
Hi Hamish,
Deb had an example rule that limited the number of sessions per VIP but she was waiting on a method to count the current number of records from the session table:
Click here
You might try replying to that post to keep everything together.
Aaron
HamishCirrocumulus
And the rule is done...
http://devcentral.f5.com/wiki/default.aspx/iRules/HTTP_Session_Limit.html
Which uses the new table command in LTM 10.1.0 to count the number of actual sessions (Not connections) and redirect to a suitable holding page.
The expansion of the iRule to eliminate the obvious 'features' desirable or otherwise is left as an exercise for later.- hoolioHi Hamish,
That looks like a great start. A few minor notes:
- RULE_INIT runs once per TMM instance on CMP compatible platforms/rules
- you can use the static name space instead of a global variable to maintain CMP compatibility (set ::max_active_clients 5 would be set static::max_active_clients 5)
Aaron