Viewing Event Property Information

Viewing Event Property Information

The Event Property Histogram (Figure 17-7) shows the properties that accompany every event that occurs in a latency recording; for example:

For a "File Write" event this is the number of bytes that were written.
For a "Java Blocked" event, this is the class of the object the thread used as a lock along with other information.

Figure 17-7 Event Properties histogram

Event Properties histogram

How the Histogram Works

The histogram shows the distribution of these event properties so that you can see the total latency that occurred when an event property had a certain value. The histogram is useful if you want to see latencies grouped by lock class. You can then add all the events that locked on a certain class to the operative set. The graph and trace tab will then show you in which threads the lock contention occurred or where in the code it happened.