Heap dump
A heap dump is a diagnostic snapshot of the objects, values, and references present in a managed runtime heap at a particular time.
Troubleshooting Java, Second Edition
A heap dump is a diagnostic snapshot of the objects, values, and references present in a Java heap at a particular time.
- How it is used
- Supports post-crash and memory-allocation investigations when profiling is unavailable or an OutOfMemoryError has stopped the application.
- How deep it goes
- Explains capture methods, VisualVM inspection, object sorting, and reference tracing, while deferring advanced querying to OQL.
- Examples
- Uses Product and String instances retained by a static ArrayList, plus VisualVM object and reference views.
- What you can do after
- Diagnose memory leaks and retained objects with VisualVM, command-line dumps, object views, reference paths, and OQL.
Read how Troubleshooting Java, Second Edition explains heap dump →
The Art of Code
A heap dump is a snapshot of the objects and memory state of a managed runtime heap at a particular time.
- How it is used
- Uses heap dumps for post-mortem inspection of Java memory during fatal failures and exploratory investigation of leaks or memory pressure.
- How deep it goes
- Defines heap dumps and their diagnostic role, but stops short of specifying capture commands, dump formats, or interpretation procedures.
- Examples
- Uses OutOfMemoryException, production-only failures, garbage-collection logs, thread dumps, and resource baselines as diagnostic examples.
- What you can do after
- Diagnose memory-related Java failures by correlating heap state with runtime, application, and infrastructure evidence.
Related concepts
- VisualVMused by · VisualVM is a Java monitoring and profiling tool for inspecting running applications, JVM behavior, resource usage, and performance.
- Object Query Languageused by · Object Query Language is a query language for retrieving and examining objects and related data in heap dumps.
- heapaddresses · A runtime memory region from which dynamically allocated data is obtained and whose storage is managed independently of individual function call frames.
- JVMconfigured by · The Java Virtual Machine is an abstract runtime environment that executes Java bytecode and compatible compiled code according to defined execution semantics.
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