Java Performance Tuning, Profiling, and Memory Management

Java performance tuning can seem like an elusive concept until you face the impacts. Learning how to improve Java Virtual Machine (JVM) performance is critical, but it requires you to develop a rather advanced skill set in order to do it effectively.

In this article, we'll explore the controls and switches you can change in order to tune your JVM to best suit your application.

Always Use Performance Profiling

Tuning the performance of your JVM begins with profiling its current performance, which is why the built-in Java Flight Recorder is such a useful tool.

The Java Flight Recorder is a performance profiling tool that's available out of the box with any JVM setup.

There's no reason to disable it, because it's lightweight, with less than a 1 percent impact on the performance of your applications at its default settings.

When you use Java Flight Recorder, you'll be able to inspect a log of all the events that lead up to a crash or runtime failure.

That's why you should always keep it running, even if you're dealing with a resource-heavy application. In fact, that's when you'll get the most valuable insights from this little tool.

Balance Sampling and Instrumentation

When it comes to monitoring the performance of your JVM, you can take one of two approaches: sampling or instrumentation.

The Java Flight Recorder uses the sampling approach, which is great because its load is predictable.

Instrumentation, on the other hand, offers more exact results. Instrumentation requires additional code to be added to help identify performance issues.

There's no one-size-fits-all approach. In reality, you'll need a healthy balance of both sampling and instrumentation.

Sampling is great for end-to-end visibility, while instrumentation is ideal for effectively drilling down into a performance issue once you know where it exists within your code base. Strategically using both approaches will help you fine-tune JVM performance.

Use AI-Powered Analytics

Most performance issues in Java follow a predictable pattern. So, before you start diving in to the details, get in the habit of using an AI-powered analytics tool to help you identify the problem quickly.

Most profiling tools will quickly categorize your performance issue so you have a good starting point, and sometimes they can even point out the exact line of code where the problem is happening.

Finding a good AI-powered analysis tool will prove to be a powerful asset as you move forward with Java performance tuning.

After all, these tools can quickly spot issues that aren't apparent to the human eye, potentially saving countless hours of tedious searching.

Maintain Performance History

As part of every continuous integration build, you should be running a performance test suite where Java Flight Recorder is logging everything.

This allows you to save the Flight Recorded data into GitHub, creating a benchmark for application performance as you move through versions. Checking this data will help you see how performance changes over time.

Oftentimes, you won't notice that something you changed is threatening performance until down the line, but by comparing data over weeks or months, you'll see patterns that will help you trace the problem back to the source.

You can also use this data to keep performance within acceptable ranges. If performance for a new version doesn't meet the mark, tell your developers to start again.

Implement Modern Profiling Tools

It's human nature to become set in our ways, but when it comes to something like a Java profiling tool, that's a detrimental thing to do.

You should constantly seek out the latest and greatest when it comes to performance profiling software because the requirements are always changing.

The tools you used a decade ago to troubleshoot your Tomcat applications aren't nearly as valuable as the tools that exist specifically for today's containerized apps and microservices builds.

Application development is constantly evolving, so don't ever let company loyalty or convenience stop you from changing over to something better.

VisualVM is a popular profiling and monitoring tool for JVMs, but newer tools like Java Mission Control offer even better visuals and the ability to deeply inspect your metrics.

You can also find tools built specifically for bytecode packaged inside of containers or for applications deployed to Kubernetes.

Whatever analysis tools you use, make sure they match your application and its needs.

We highly suggest to everyone to compile a check list for every step of the process that you look forward on going through.

Partner With Performance Experts

Java performance tuning is only the tip of the iceberg. If you're going down the path of profiling and tuning the performance of your JVMs, you're going to need a lot of practice and new tools to pull it off.

Even the best Java developers can find themselves getting stuck when it comes to efficiently tuning Java apps.

As your applications grow more complex, Java performance tuning grows more essential, but that doesn't make it any easier to achieve.

Fortunately, your business doesn't have to fall victim to the common pitfalls and roadblocks.

Instead of spending months trying to perfect your performance profiling and tuning, call in the experts and let the performance raise.

At Adservio, building resilient digital experiences is all we do. We're committed to improving performance by supporting scalable, highly available, and fast applications.

So, if you need help implementing the best practices of Java performance tuning, look no further. Contact our team today to see how we can help.