- System requirements
- Profiler architecture
- Running the profiler
- Profiler activation
- Start profiling
- Solving performance problems
- CPU profiling
- CPU usage estimation
- Sampling
- Asynchronous sampling
- Tracing
- Call counting
- CPU tab
- What-if: an ability to ignore particular methods or focus on particular methods only
- Comparing performance snapshots
- Sampling settings
- Tracing settings
- Threads
- Deadlock detector
- Memory profiling
- Garbage collection
- Monitor profiling
- Exception profiling
- Probes: monitor events of various kinds
- Performance Charts
- Inspections: automatic recognition of typical problems
- Automatically trigger actions on event
- Summary, snapshot annotation, automatic deobfuscation
- Time measurement (CPU time, wall time)
- Filters
- Snapshot directory customization
- Export of profiling results to HTML, CSV, XML, plain text
- Profiler Java API
- Profiler HTTP API
- Command line tool to control profiling
- Settings
- FAQ: How to profile in my scenario?
Sampling
Sampling is one of the CPU profiling modes.
When sampling is used, the profiler periodically queries stacks and times of running threads to estimate the slowest parts of the code. In this mode method invocation counts are not available.
Use profiler toolbar to start CPU sampling as shown on the picture below. There are also alternate methods to start CPU profiling.
Overhead
Sampling is typically the best option when your goal is to locate and discover performance bottlenecks. With sampling, the profiler adds virtually no overhead to the profiled application. However, the probes for the high-level statistics, if enabled, may impose additional overhead.
See also: Profiling overhead: how to reduce or avoid.
Sampling settings
You can configure some CPU sampling aspects with CPU sampling settings.