can we rotating log hourly?

An older version of that solution for version 9.X is here:

http://support.f5.com/kb/en-us/solutions/public/4000/200/sol4235.html

I shows there is a cron.hourly. I'm guessing that moving the lograte file into that directory would do it. I'm not sure why the version 11.X doesn't mention the hourly. You may wan to contact F5 support to see if there's a reason why that solution doesn't mention hourly as an option in case it may break something.