XRebel Frequently Asked Questions

XRebel is a lightweight Java code analysis and performance profiling tool developed by Perforce Software. It provides real-time performance insights during development, enabling developers to identify and resolve performance issues early in the software development lifecycle. Unlike traditional profilers, XRebel uses a request-based approach, offering detailed visibility into application behavior, including method execution times, database interactions, and microservices communication.

Key capabilities include:

• Real-time, request-based profiling
• SQL/NoSQL I/O monitoring (including N+1 detection)
• Distributed tracing across microservices
• Exception and log analysis with reversed stack traces
• Code structure visibility for efficient debugging

XRebel operates by integrating into your Java application's runtime environment. It captures performance data for each request, highlighting the most time-consuming methods and interactions. This includes monitoring SQL and NoSQL I/O, tracing microservices, and displaying logs and exceptions in real-time. The tool presents this information through an in-browser toolbar, allowing developers to analyze performance metrics as they code.

Yes. XRebel’s free download includes a fully featured 14-day trial license. If you think that two weeks is not enough, ask for an extension from sales@perforce.com.

XRebel distinguishes itself through its request-based profiling approach, focusing on individual requests rather than system-wide metrics. This method provides developers with immediate, actionable insights into specific performance issues during development, without the overhead typically associated with full-scale Application Performance Monitoring (APM) tools. Additionally, XRebel's real-time feedback and in-browser visualization facilitate a more efficient debugging and optimization process.

It’s not meant to replace production APMs, but rather to catch problems earlier when they’re cheaper and easier to fix.

XRebel helps detect:

• Slow method execution
• Inefficient SQL or NoSQL queries (including N+1 problems)
• Excessive object allocation
• Blocking I/O
• Memory and CPU spikes
• Exceptions and API inconsistencies across microservices
• Latency in distributed requests

XRebel enables Shift Left by integrating directly into the development environment to:

• Catch performance issues during coding, not during QA or production
• Reduce fix time by up to 60%
• Prevent production outages and performance debt
• Support developers with real-time data so issues don’t escalate into architectural rewrites

Comprehensive installation guides for various environments are available in the XRebel Documentation. These guides cover integration with popular IDEs like Eclipse and IntelliJ IDEA, as well as application servers such as Tomcat, JBoss, and GlassFish. If you need any extra support, feel free to reach out to our team of experts—we’re here to help.