vCenter 5.1 WebClient HTTP access log?

Hi, all.

I'm building a large vSphere 5.1b environment and I bumped a problem regarding WebClient.

Where can I find the HTTP(S) access log of vCenter WebClient?

http://kb.vmware.com/kb/2004090

This kb shows the location of access log for vCenter 5.0 but not for 5.1.

And created client log bundle doesn't include http access log at serviceability directory ( I believe this is where access log is stored, but it was empty!)

Should I enable access log somewhere? or it's not implemeted ?

Or if you want to audit the users' access and their activity, checking the vCenter log is more appropriate?

Any advice is welcome!

Thank you for advance.