HPjmeter 4.2 User's Guide

Lock Contention The thread is delayed while attempting to enter a Java monitor that is

already acquired by another thread.

Running All remaining cases.

Guidelines

• Large amounts of red in Thread Histogram indicate heavy lock contention, which is usually

a possible problem. On the other hand, large amounts of green indicate a potential processing

capacity for the involved threads.

• When there is no load, the state for the threads doing the work on behalf of transactions

should be waiting, and marked by the green color.

• Threads terminating normally, or because of uncaught exceptions, appear as a discontinued

row.

• Multiple short-lived threads appear as apparently blank rows in the display. At the same

time the number of displayed threads, shown at the bottom of the display, is large.

• Lock Contention appears as red in the display.

• Deadlocked threads appear as two or more threads spending all their time in lock contention,

red, starting from a given time. This point in time identifies the deadlock occurrence.

Details

For each time slice, represented by a small portion of the X-axis, the display along the Y-axis

shows the percentage of the time slice that the thread spent in each state. It represents a stacked

bar graph for the time slice.

Figure 8-13 Monitoring Metric: Thread Histogram