Forum Discussion
Gary_105208
Nimbostratus
NimbostratusHow to Generate Visitor ID/UUID
We're trying to drop a unique visitor cookie that we control the persistence (i.e. 6 months age). I don't see anything in the iRule reference that close to helping.
Any recommendation on how to generate an unique identifier, or ideally UUID?
I see some UUID TCL libraries at http://tcllib.cvs.sourceforge.net/viewvc/tcllib/tcllib/modules/uuid/uuid.tcl?revision=1.9&view=markup but I don't believe these can be loaded into the F5?
Once I have that I can handle all the cookies, etc. I just need a unique id generator.
Thanks, Gary
12 Replies
StephanMantheyNacreous
To generate a random 9-digit number you can use the following:
when HTTP_REQUEST {
set client_id [format %09d [expr int(rand() * 1e9)]]
}
The exponents maximum is 9. Modify both the format-string and the exponent if required, please.
hoolioCirrostratus
Thanks for the tip. That's a bit cleaner than the method we came up with in the linked post. You could wrap the expr arguments to save some conversions:
% time {format %09d [expr int(rand() * 1e9)]} 1000
21 microseconds per iteration
% time {format %09d [expr {int(rand() * 1e9)}]} 1000
6 microseconds per iteration
Aaron
