A Liberty server dump provides a comprehensive set of information about the state of a Liberty server. It's one of the most useful tools for IBM service to investigate problems in a Liberty server, but can also provide some interesting daignostics to end users. Obtaining a server dump ...
In a previous post , we discussed how to perform live container debugging on OpenShift using worker node debug pods. This helps with the case when you want to gather diagnostics from a container without restarting it, but that container doesnโt have sufficient diagnostic tools built-in. In this...
In a previous post on Java Performance Tools: Sampling Profiler , we covered how to use the Health Center sampling profiler available in IBM Java to investigate Java CPU usage in a low overhead way. One additional question people often have is how to figure out what's driving Java memory...
Caching is the process of saving the result of a calculation and potentially re-using it in the future to reduce response times, increase throughput, and reduce load on servers. Caching is a critical and often under-tuned aspect of performance. In this article, we'll cover how to understand Java...
As discussed in a past blog post , if you're experiencing performance problems, after you've reviewed that garbage collection (GC) is healthy , and you've reviewed thread dumps , the next step is to review a sampling profiler. This gives you more detailed information about what's using CPU...
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As discussed in a past blog post , if you're experiencing performance problems, after you've reviewed that garbage collection (GC) is healthy , the next step is to review thread dump stacks during a performance issue. This gives you a sample of what your application is doing and often leads to...
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As discussed in a past blog post , if you're experiencing performance problems, the first thing to check is whether your garbage collection (GC) is healthy. If the proportion of time in garbage collection is greater than ~10%, then garbage collection is likely unhealthy and the application is...
In our previous blog post , we discussed the value of running the Linux perf native CPU sampling profiler to investigate Java CPU usage in production. However, perf generally requires root access and OpenShift application containers generally don't run with such privileged access. This...
If your Java workload is experiencing high CPU in production, the basic workflow is generally the following. This article will quickly review the first three steps and then we'll focus on the fourth step in green: Review a native sampling profiler. Garbage Collection The first thing to...
In previous blog posts we explored optimizations for running Liberty in containers. Part 1 covered optimizations for the JVM and Part 2 covered Liberty containers basics. In this post, we will cover deployment options and performance optimizations for Liberty containers in Kubernetes...