alibaba/arthas
Arthas
Arthas is a Java diagnostic tool and runtime debugger designed for real-time troubleshooting of applications. It functions as a remote diagnostics agent that allows users to inspect the runtime state of a Java process, including its heap objects and classloader hierarchies, without requiring a process restart.
The project distinguishes itself through advanced bytecode manipulation capabilities, enabling live class hotswapping and the modification of bytecode in running processes. It supports in-memory source compilation and runtime bytecode decompilation to verify and update logic instantly within a live environment.
Its broader capabilities cover JVM performance profiling via flame graphs and CPU analysis, as well as comprehensive monitoring of method invocations, call stacks, and memory leaks. The tool also provides utilities for class loading analysis to resolve library conflicts and a system for extending functionality through custom diagnostic commands.
Features
- Runtime Debuggers - Provides an interactive interface for analyzing and debugging running Java applications in real time.
- Runtime Diagnostics - Troubleshoots live Java applications in real time to identify bugs and performance issues without restarting the process.
- Bytecode Manipulation - Modifies class bytecode at runtime using ASM to insert probe logic for method tracing and monitoring.
- JVM Profiling Tools - Analyzes CPU usage, thread stacks, and method execution times using flame graphs to locate system bottlenecks.
- CPU Profilers - Analyzes CPU usage and thread states to identify resource-heavy processes and performance bottlenecks.
- Java Diagnostic Toolkits - Provides a toolkit for real-time troubleshooting of Java applications including bytecode manipulation and runtime state inspection.
- Decompilers - Converts compiled Java bytecode back into human-readable source code to verify logic in the live environment.
- Runtime Bytecode Instrumentation - Modifies live classes and injects bytecode into running processes for immediate logic updates.
- Runtime Class Modifications - Replaces existing classes in the JVM at runtime without requiring a process restart.
- Dynamic Class Redefinition - Leverages the JVM Tool Interface to replace loaded classes in memory for live code updates and hotswapping.
- In-Memory Compilers - Transforms Java source files into executable bytecode directly within the runtime environment for immediate iteration.
- Application Diagnostics - Enables real-time troubleshooting of running applications to identify bugs and performance issues without restarts.
- Performance Profiling Tools - Provides detailed timing and resource statistics for individual method invocations to locate bottlenecks.
- Process Attachment Tools - Uses the Java Attach API to inject a diagnostic agent into a running process without requiring a restart.
- Flame Graph Generators - Generates interactive flame graphs from profiling data to visualize the most time-consuming code paths.
- Heap Inspection Tools - Allows retrieving and extracting live object instances from the system memory heap for detailed inspection.
- Call Stack Navigators - Retrieves full stack traces of specific method invocations to identify calling functions and execution paths.
- Remote Diagnostic Consoles - Enables connecting a remote console via network protocols or web browsers to perform remote troubleshooting.
- Runtime State Inspectors - Inspects JVM memory usage and thread stacks to diagnose overall system health and configuration.
- Remote Management Agents - Provides a server-client system that allows remote connection to a running Java process via network protocols or web browsers.
- Traffic Tunneling - Proxies WebSocket connections from a remote browser to a local agent to enable remote diagnostics.
- Invocation Inspection - Captures real-time method parameters and return objects to observe specific function calls.
- Invocation Logging - Stores method parameters and return values in a history log for later replay and inspection.
- Classloader Hierarchy Analysis - Traverses the JVM classloader tree to map the origin and loading sequence of specific Java classes.
- Conflict Resolution - Identifies the source of loaded classes to resolve version conflicts between different library files.
- Hierarchy Inspection - Queries loaded classes and analyzes the classloader hierarchy to verify the runtime environment.
- In-Memory Compilation - Compiles Java source code into bytecode within the running process for immediate deployment of diagnostic logic.
- Method Performance Metrics - Provides real-time quantitative metrics for method calls, including requests per second and response times.
- Execution Tracing - Records the sequence of operations and function calls, including input parameters and timing, for performance analysis.
- Metric and Performance Monitors - Tracks high-frequency CPU usage and garbage collection statistics to observe system-level performance.
- Remote Java Troubleshooting - Connects to a running Java process from a remote console or browser to diagnose issues in production environments.
- Statistical Profilers - Captures periodic stack traces to generate flame graphs and identify CPU bottlenecks in the executing application.
- Web-Based Remote Terminals - Facilitates communication between a remote browser and the local agent via a proxy for out-of-process diagnostics.
- Memory Leak Detection - Inspects heap objects and classloader statistics to detect memory leaks and verify resource allocation.
- Data Interception - Captures real-time parameters and return values from method calls to analyze application behavior.
- General Utilities - Troubleshoot production issues without modifying code.
- Java and JVM Ecosystem - Diagnostic tool for monitoring and troubleshooting Java applications.
- Memory Malware Tools - Advanced Java diagnostic tool for runtime analysis.
- Threat Detection - Diagnoses and monitors Java applications for suspicious behavior.
