Thread Dump Analysis

Thread dump analysis is essential for diagnosing Java application performance issues. Through our analysis functionality at threadanalyzer.online, developers can quickly identify common thread issues, such as deadlocks and thread pool resource exhaustion.

Understanding Thread Dumps

A thread dump captures all active threads within a Java Virtual Machine at a specific moment. Each thread entry contains:

• Thread name and ID
• Current execution state
• Stack trace showing execution path
• Lock information

When properly interpreted using a thread dump analyzer, these snapshots reveal crucial insights into application behavior.

How to Analyze Thread Dumps

Capturing Thread Dumps

Obtain thread dumps using the jstack utility:

jstack <pid> > threaddump.txt

For intermittent issues, capture multiple dumps at 10-30 second intervals to identify patterns.

Using the Thread Dump Analyzer

1. Navigate to threadanalyzer.online
2. Click "Get Started" on the homepage
3. Upload your thread dump file
4. Click "Analyze" to process it
5. Review the generated results

The thread dump analyzer transforms raw data into structured, actionable information.

Understanding Analysis Results

Summary Overview

The thread dump analyzer provides a high-level summary:

• Analyzed File: acsrv4-3.txt

• Total Threads: 400 threads identified in the application

• State Distribution

  • RUNNABLE: 208 threads (52.0%) - Actively running or ready to run
  • BLOCKED: 0 threads (0.0%) - Waiting to acquire a monitor lock
  • WAITING: 89 threads (22.3%) - Waiting indefinitely for another thread
  • TIMED_WAITING: 93 threads (23.3%) - Waiting for a specified period

This distribution immediately provides insights into the application's health. The thread dump analyzer highlights that the absence of BLOCKED threads suggests no immediate deadlock issues, while the high percentage of RUNNABLE threads indicates active processing.

Thread Pool Analysis

Click "View Details" to see specific thread pool information:

• Total Threads in Pool: 78 threads

• State Distribution within Pool

  :

  • WAITING: 64 threads (82.1%)
  • TIMED_WAITING: 11 threads (14.1%)
  • RUNNABLE: 3 threads (3.8%)

This distribution differs significantly from the overall application, with most pool threads in WAITING state, suggesting this pool might be underutilized or waiting for resources. The thread dump analyzer allows you to examine the call stack of each thread, helping you locate problematic code blocks.

Common Threading Issues Identified by Thread Dump Analyzer

Deadlocks

Deadlocks occur when threads are permanently blocked waiting for resources held by each other. The thread dump analyzer automatically detects and highlights deadlock cycles.

Thread Pool Exhaustion

When all threads in a pool are busy, new tasks must wait. The thread dump analyzer helps identify when pools are approaching capacity.

Lock Contention

Multiple threads competing for the same locks can degrade performance. The thread dump analyzer reveals "hot locks" where threads are blocked.

Best Practices for Effective Analysis

1. Collect multiple dumps - A single dump represents just one moment. The thread dump analyzer provides more valuable insights when comparing multiple dumps.
2. Correlate with other metrics - Combine thread dump analyzer findings with CPU, memory, and GC metrics.
3. Focus on patterns - Look for recurring patterns rather than isolated incidents.
4. Understand normal behavior - Establish baseline thread patterns during normal operation so abnormalities are easier to spot with the thread dump analyzer.

By leveraging a comprehensive thread dump analyzer and following these practices, development teams can quickly diagnose and resolve complex threading issues that might otherwise cause significant production problems.