In this article, I will go through how to spin up a stub/mock server and proxy server using netcat.

netcat linux networking proxy-server stub-server mock-server tcp http debugging command-line testing api-testing system-administration

Use case: Usually, when integrating with external service endpoints in your backend application, you will be using libraries (require('https') for Nodejs, import requests or import aiohttp for Python, HttpUrlConnection for Java, etc.) to make HTTP calls. It might be difficult...

tcpdump networking debugging http https packet-analysis network-troubleshooting wireshark system-administration linux macos command-line api-integration

When your java application is getting unresponsive or requests are taking time, taking thread dumps will help find the cause.

java jvm thread-dump debugging performance troubleshooting concurrency deadlock thread-analysis profiling enterprise-java monitoring

The purpose of this article is to explain how a kernel can invoke (out-of-memory) oom killer to kill a process abruptly which might be a java or node process of your application and what steps we can take to resolve...

java linux oom-killer kernel memory-management system-administration debugging troubleshooting process-management monitoring dmesg

In your java application, if you had seen the below error in logs. SOURCE:java.lang.OutOfMemoryError: unable to create new native thread The above error means that when java process wants to create a new thread and requests for a new process...

java jvm out-of-memory debugging performance troubleshooting memory-management ulimit native-threads system-administration linux tuning

Below is one example of analyzing heap dump to know which objects are responsible for JVM out of memory.

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