Move the writing of the PerformanceLog into a middleware

[bschmalhofer]

Things like access logs seem to make more sense as a middleware than as integrated into the interface modules. The changed behaviour would be that the Login-Requests and the failed PreApplication modules would be logged too, But IMHO this is more a feature than a bug.

[bschmalhofer]

Moved this to Wishlist, as the current performance log depends on having logging set up and that the user data is available. IMHO both of these are not really needed for a performance log.

[bschmalhofer]

Checked again whether the user information is used anywhere in the AdminPerformanceLog frontend module. Thus I propose to remove that information from the performance logfile and to move the performance log functionality into a middle ware.

[bschmalhofer]

While looking into this I noticed that the detailed view of the performance log is off.

This is from a fresh installation that is only some minutes old. The data seems to be correctly aggregated by 1 minute but the date in the very left column varies by hour. Looks like a factor of 60 was incorrectly applied somewhere along the line.

[bschmalhofer]

While looking into this I noticed that the time to create a response is measured by seconds. I see no reason for not measuring by milliseconds. Maybe once upon a time there were problems with Time::HiRes when running under windows.

I consider this as a bug.

[bschmalhofer]

While we are at it:

• rotate the file with File::Write::Rotate, or File::RoundRobin, or RRDtool files
• use Time::HiRes::tv_interval()for taking the time

[svenoe]

Can be looked at, if there are any new requests concerning logs.