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Trace / Trace Method Invoke Chain

Trace Method Invoke Chain

Use 'trace {{class-pattern}} {{method-pattern}}' in Trace to monitor method calls in a live Java env. Useful for performance diagnostics.

More Trace

Terminal

trace <class-pattern> <method-pattern>

trace <class-pattern> <method-pattern>

#!/bin/bash

# Trace Method Invoke Chain
trace {{class-pattern}} {{method-pattern}}

import subprocess

# Trace Method Invoke Chain
# Make sure to replace <placeholders> with actual values
def run_command():
    cmd = [
        "trace",
        "<class-pattern>",
        "<method-pattern>"
    ]
    
    try:
        print(f"Executing: {' '.join(cmd)}")
        subprocess.run(cmd, check=True)
    except subprocess.CalledProcessError as e:
        print(f"Error: {e}")
    except FileNotFoundError:
        print("Error: trace not found. Please install it first.")

if __name__ == "__main__":
    run_command()

When To Use

Deploy 'trace {{class-pattern}} {{method-pattern}}' when diagnosing method invocation paths in a real-time Java application. This is critical when pinpointing performance bottlenecks or verifying the behavior of complex systems without stopping the application.

Pro Tip

Avoid tracing with overly broad patterns in production. The performance overhead can be significant, and excessive logging may lead to storage and I/O constraints.

Command Builder

Tune the command before you copy it

Back to syntax

Generated Command

trace <class-pattern> <method-pattern>

Terminal Output

Expected runtime feedback

Simulated preview

Output

Tracing method invocation chain for patterns:

Class Pattern: com.example.*
Method Pattern: *.calculate()

+-------------------------+---------------------+
| Class Name              | Method Name         |
+-------------------------+---------------------+
| com.example.ServiceA    | calculate()        |
| com.example.ServiceB    | calculate()        |
| com.example.ServiceC    | calculate()        |
+-------------------------+---------------------+

Trace completed successfully!

Anatomy of Output

Understanding the result

TRACE ENTRY: com.example.Service.doAction() Trace Entry

Marks entry into the method, useful for call sequencing.

ARG0: java.util.List Argument Type

First method argument, indicating parameter pass-through.

RETURN: void Return Type

Method return type, confirming void methods do not return values.

TRACE EXIT: com.example.Service.doAction() Trace Exit

Confirms method completion, essential for measuring execution time.

Power User Variants

Optimized versions

trace com.example.* log.*

Traces all logging method invocations to troubleshoot logging performance.

trace com.database.ConnectionPool get*

Tracks all getter methods in the connection pool for resource leaks.

Unix Pipeline

Shell combinations

trace com.example.Service do* | grep 'elapsed time'

Combines trace with grep to extract only execution time details for 'do' methods.

trace com.example.* * | awk '/Service/'

Filters traced methods specific to a service pattern using awk for comprehensive analysis.

Troubleshooting

Common pitfalls

ERR: ClassNotFoundException

Solution: Ensure class pattern is correct and the JVM has access to the classpath.

ERR: SecurityException

Solution: Verify permission settings that allow tracing on the chosen JVM process.

ERR: NoSuchMethodException

Solution: Confirm the method pattern matches existing methods within the class scope.

Command Breakdown

What each part is doing

trace: Base Command; The executable that performs this operation. Here it runs Trace before the shell applies any redirect operators.
<class-pattern>: class pattern; The value supplied for class pattern.
<method-pattern>: method pattern; The value supplied for method pattern.

How To Run

Execution path

Step 1
Run the command: trace com.example.* *.calculate()
Step 2
Monitor the output for the methods invoked and their execution sequence.
Step 3
Use the output to identify any performance issues or unexpected behavior.

Alternative Approaches

Comparable commands in other tools

Alternative observability tools for the same job.

Trace Cmd / Display Recorded Trace Specific Cpu Linux sudo trace-cmd report --cpu <cpu_number> Trace Cmd / Start Tracing With Plugin Linux sudo trace-cmd start -p <function|function_graph|preemptirqsoff|irqsoff|preemptoff|wakeup|...> Trace Cmd / Stop Tracing Retain Buffers Linux sudo trace-cmd stop Trace Cmd / Record Trace With Plugin Linux sudo trace-cmd record -p <plugin> Trace Cmd / Clear Trace Buffers Linux sudo trace-cmd clear