- System requirements
- Profiler architecture
- Running the profiler
- Profiler activation
- Start profiling
- Solving performance problems
- CPU profiling
- Threads
- Deadlock detector
- Memory profiling
- Memory telemetry
- Memory snapshot
- Object allocation recording
- Shallow and retained sizes
- Memory views
- Objects view
- Class list
- Class and package
- Class loaders
- Web applications
- Object generations
- Reachability scopes
- Shallow size
- Object explorer
- Biggest objects (dominators)
- Allocations
- Object ages
- Merged paths
- Class hierarchy
- Method merged callees view
- Method back traces view
- Quick info view
- GC roots view
- Leak detection: working with paths
- Memory inspections
- Comparing memory snapshots
- Support of HPROF format snapshots
- Support of Java Flight Recorder (JFR)
- Support of Portable Heap Dumps (.phd)
- Values of primitive types
- Persistent object IDs
- Useful actions
- Set description language
- 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?
Class list
This view is a powerful tool for examining how memory is distributed among instances of different classes.
Classes are shown as a plain list. To see them grouped by package, use Class and package.
Information for a class is shown in four columns: "Class", "Objects" (number of objects), "Shallow Size" and "Retained Size" (for details please see Shallow and retained sizes).
Classes whose objects retain most memory are shown at the top, as the list is sorted by retained size.
On opening the view, estimated retained sizes are shown instead of exact sizes, which cannot be immediately calculated. The exact sizes may be obtained by using "Calculate exact retained sizes" balloon above the "Retained Size" column. However, for most classes the estimation is very close to the exact value, so there is almost no need to run exact size calculation.
To open all instances of a class by its name use Memory | Instances by Class... (Ctrl+N)