[Java Concurrency] 02: Runnable

One of the methods to run tasks in multiple thead is to pass Runnable instance to thread and call that start() method. Runnable is a Functional interface that has only one method that returns void. If you prefer the lambda syntax, you can write the above code like so: However, for tasks with more than … Read more

[Java Concurrency] 01: Thread & Process

What is a thread? Thread is the smallest execution unit that can be schedule by the operating system. A process is a running program. When you start a program, you create a process.In one process, there can be more than one thread. Threads in a process share an environment created by the process. System vs … Read more

Configure HAProxy to Accept Preflight Requests (CORS)

Recently I developed an API with Spring Boot. All the tests on the local environment went well with Postman. However, when deploying to prod through HAProxy, I got this CORS error: There are also other errors regarding missing headers, origin… There are some solutions available, such as adding code to my Spring Boot code base. … Read more

Top Useful Copy-Paste Commands For Apache Solr

Create an user To create an user in Solr, first, you need to enable authentication plugin by creating a file named security.json under /var/solr/data. Enter into your Solr environment (docker or command line where you have Solr installed) and execute the following command: This command creates the security.json file at the correct location and also … Read more