Imagine this scenario: Your cool microservice works fine from your local machine but fails when deployed into your Red Hat OpenShift cluster. You cannot see anything wrong with the code or anything wrong in your services, configuration maps, secrets, and other resources. But, you know something is not right. How do you look at things from the same perspective as your containerized application? How do you compare the runtime environment from your local application with the one from your container?
If you performed your due diligence, you wrote unit tests. There are no hard-coded configurations or hidden assumptions about the runtime environment. The cause should be related to the configuration your application receives inside OpenShift. Is it time to run your app under a step-by-step debugger or add tons of logging statements to your code?
We’ll show how two features of the OpenShift command-line client can help: the
oc run and
oc debug commands.
Continue reading “Troubleshooting Red Hat OpenShift applications with throwaway containers”
JDK Mission Control is now the newest member of the Red Hat Software Collections (RHSCL). JDK Mission Control is a powerful profiler for HotSpot Java virtual machines (JVMs) and has an advanced set of tools that enable efficient and detailed analysis of the extensive data collected by JDK Flight Recorder. The toolchain enables developers and administrators to collect and analyze data from Java applications running locally or deployed in production environments using OpenJDK 11.
In this article, I will go through a primary example of setting up JDK Mission Control. For Linux, JDK Mission Control is part of the RHSCL and, for Windows, it is available as part of the OpenJDK zip distribution on the Red Hat Customer Portal. For Linux, these instructions assume that Red Hat Build of OpenJDK 11 is already installed. I will show how to set up the system to install software from RHSCL, which provides the latest development technologies for Red Hat Enterprise Linux. Then, I will install the JDK Mission Control and run a simple sample application. The whole tutorial should take fewer than 10 minutes to complete.
Continue reading “Set up JDK Mission Control with Red Hat Build of OpenJDK”
Production being affected by software issues is always an unwanted scenario. Diagnosing production issues, however, should never be an unplanned activity. Structured testing and QA efforts would ideally prevent any software bugs from entering production. So the dilemma is how to prepare for something unexpected in production that was not considered during the earlier testing and QA phases.
This article discusses Byteman, a tool that leverages the Java Instrumentation API to inject Java code into methods without the need to recompile, repackage, or even redeploy the application.
Continue reading “Diagnosing Java applications on the fly with Byteman”
The most common problem when people are trying to deploy an Open vSwitch with Data Plane Development Kit (OvS-DPDK) solution is that the performance is not as expected. For example, they are losing packets. This is where our journey for this series of blogs will start.
This first blog is about Poll Mode Driver (PMD) thread core affinity. It covers how to configure thread affinity and how to verify that it’s set up correctly. This includes making sure no other threads are using the CPU cores.
Continue reading “Troubleshooting Open vSwitch DPDK PMD Thread Core Affinity”
In my previous article, Enabling Byteman Script with Red Hat JBoss Fuse and AMQ – Part 1, we found a basic use-case for Byteman scripts with Red Hat JBoss Fuse or Red Hat JBoss AMQ. However, the log file was generated separately and only limited operations were possible. In this article I will show you how to use a Java helper class. By using Java, we get advanced operations to view or modify the content. Also, using java.util.logging allows us to log the statements to fuse.log, avoiding the creation of any other log file.
Continue reading “Enabling Byteman Script with Red Hat JBoss Fuse and AMQ – Part 2”