Monitor profiling

Goals of monitor profiling
Controlling monitor profiling
Monitors tab

Goals of monitor profiling

Monitor profiling helps you analyze synchronization issues, including:

which threads were calling wait(), and for how long
which threads were blocked on attempt to acquire a monitor held by another thread (synchronized methods/blocks), and for how long

The times are measured as wall time.

Controlling monitor profiling

Profiler UI

When the profiler is connected to the profiled application, the toolbar contains the following monitor profiling controls:

Toolbar Button	Description
	Start/Stop monitor profiling.
	Clear monitor profiling results.

When monitor profiling is started, previous results are cleared automatically.

Agent startup options

Monitor profiling is not started by default. To launch an application with monitor profiling started, specify monitors startup option.

HTTP API

For users requiring remote control or automation within their profiling workflows, YourKit Java Profiler offers control over the monitor profiling through HTTP API endpoints. The documentation outlines startMonitorProfiling, stopMonitorProfiling and resetMonitorProfiling methods available for this purpose.

Java API

The YourKit Java Profiler also provides a Java API for deep integration with Java applications. The com.yourkit.api.controller.v2.Controller includes methods for starting, stopping, and resetting the monitor profiling, similar to the toolbar buttons.

Monitors tab

Monitor profiling results can be analyzed from different perspectives:

as a Wait tree - All threads merged, with method wait times and counts in a single call tree.
as a Wait tree - By thread, with method wait times and counts in call trees grouped by individual threads.
as a Flame graph of waiting methods.
grouped by monitor Owner thread.
grouped by monitor Monitor class.