J-Spring 2022: Martijn Dashorst – Lessons Learned: Going from Floppy Disks to Cloud Deployments

https://jspring.nl https://nljug.org While our predecessor product(s) were a COBOL application and later a Windows client/server application distributed on floppies, since 2005 we rock a Java web application that has gone through a lot of changes to keep up with the times. No longer duplicating 5 1/4” 1.2M floppies over the weekend and mailing them to our customers, but a single `git push` will deliver our latest version to our customers. In this session you will learn how we made our application survive for 18 years and still be relevant. Learn how we rearchitected our application from 2005 to 2022, and more importantly, what we did wrong so you can avoid our mistakes. We migrated from Java 1.4 to Java 17, we moved from tomcat+hibernate+velocity via tomcat+hibernate+wicket+cxf+axis+spring+jgroups+ehcache to wildfly+wicket, from deploying on physical hardware to virtual kubernetes nodes. From manually scp-ing releases to gitops, and from Oracle to Postgresql, causing a 5 week outage. If you learn only one thing from Martijn Dashorst’s session: always have a plan B.