Forum Discussion
sundogbrew
Altocumulus
AltocumulusSSL TPS limist
I have a question about SSL connection limits. I have a license for 1100 connections. I read a doc from F5 that says you can see if you are exceeding it by looking checking your /var/log/ltm file. ...
Hamish
Cirrocumulus
CirrocumulusAh... Also be aware that the SSL TPS calculations may not be performed as you expect. A 100TPS license won't necessarily give you 100 transactions over a 1 second period, especially if the load is peaky... Counts of transactions are groups over a 10ms period. If you exceed 1/100 of the limit in a 10ms period, you'll hit the limit and the next connection will be blocked.
There's an overview in
https://support.f5.com/kb/en-us/solutions/public/6000/400/sol6475.html
The net effect is that if you've had too many TPS's in the 10ms window, the SYN packet will be dropped... The connection will then stall until the SYN is retried. Hopefully succeeding (leading to slow performance).
A good measure of when to get nervous is around half (1/2) the licensed limit (If you see 50TPS over a 60 second window I'd get nervous with a 100TPS license).
H
