Java hosting guides

How to size memory for a Java app: heap, metaspace, threads and native memory, with typical numbers per server type and the VPS size that fits.

How to set the JVM heap on a server: -Xmx, -Xms, MaxRAMPercentage, garbage collector choice, metaspace and what to do on out-of-memory errors.

Step by step: deploy a WAR file to Tomcat on Ubuntu, serve it at the root context, restart safely, read the logs and roll back. Covers Tomcat 9, 10 and 11.

Run a Spring Boot executable JAR as a systemd service: unit file, unprivileged user, environment file, restart policy, JVM options and zero-surprise deploys.

Compare Tomcat, WildFly, Payara and Spring Boot: what each is, memory use, Jakarta EE support, deployment style and which one fits your project.

Shared Java hosting or a Java VPS? Compare memory limits, Java versions, isolation, control and cost, and see when each makes sense.

Moving a Java or Tomcat application from cPanel or shared hosting to a VPS: inventory, sizing, database export, deployment, DNS cutover and a rollback plan.

Put Nginx in front of Tomcat or Spring Boot: server block, forwarded headers, WebSockets, upload limits and Let's Encrypt certificates with certbot.

Java long-term support versions compared: 8, 11, 17, 21 and 25. What changed, what each framework requires and which version to choose for a server.