• Bug
  • Status: Closed
  • 1 Critical
  • Resolution: Fixed
  • ehcache
  • hsingh
  • Reporter: amiller
  • November 06, 2009
  • 0
  • Watchers: 0
  • January 17, 2013
  • November 17, 2009



“Hit Rate” and the other “Rate” headings are problematic.

From answers.com:

The chief measurement of a cache, which is the percentage of all accesses that are satisfied by the data in the cache. Also known as “hit ratio.” See cache and hits.

The term Hit Ratio is used in the Ehcache documentation. It is the primary measure of cache efficiency.

The other issue is that “Hit Rate” is actually Hits per 7 seconds in yesterday’s demo.

All of these should be changed to “Hits/s” which means Hits per second.

If the sampling interval is 7 seconds, then the number gets divided by 7 to represent it as a per second value. This is consistent with lots of other “rate” measures.


Geert Bevin 2009-11-07

Ok, let’s run through this. Someone opens the GUI, has an inactive cache, does one hit on it … waits for the GUI to update … and sees no change since: * in the last 7 seconds there was one hit * divide by 7 = 0.14 * turn into integer = 0

=> shows 0

I’m wondering what impression this will give to people evaluating the product.

Geert Bevin 2009-11-07

Already renamed from Hit Rate to Hits (and similar for the other stats).

Alex Miller 2009-11-08

So, why don’t you just put 0.1 hits/s ?

Geert Bevin 2009-11-08

Since currently everything uses longs for the stats data, it’s a major refactoring to change that.

Alex Miller 2009-11-08

Well, I think that refactoring needs to happen anyways. Seems like we’ll need decimals for something anyways and then you could undo the per mille things from the other stat.

Geert Bevin 2009-11-08

Actually, I gave it some more thought, the internal storage of the SampledStatistic doesn’t matter much, I prefer it to be a fixed precision instead of a floating point. I can ‘fix’ this by adding a precision config or a convert method to the stat instances actually. That seems better to me. Will be after beta though :-)

Himadri Singh 2009-11-19

Verified in rev 5329