Get on the Upgrade Treadmill

Published on 2017-03-07

Always upgrade your software. Upgrading now means less pain later.

Recently my company upgraded from Apache Kafka v0.8 to the latest available version (v0.10.2). With it came wire protocol changes, two separate clients were consolidated into only one, Kafka now stores offsets in itself rather than Apache Zookeeper, and a dozen other changes that also needed to be adjusted in our golang services.

One solid outage-into-the-evening later, I've vowed two things:

Always Upgrade Your Software

If you use the latest libraries, the latest software, and constantly keep your systems up-to-date, the incremental changes end up becoming smaller and smaller as new point-versions come out. This get easier as everyone learns to "ride the wave" and make systems smaller. Constant upgrades also suggest (though they do not require) a trend toward smaller services or microservice architectures in order to keep the upgrades small in scope.

Test Everything

• If there isn't a test for a block of code, make one. If that code operates against a remote service, build a mock with expectations (or contracts) defined. If that's too much, and you have sufficient resources, run a stripped-down copy of the service locally. If you can't do that, at least consult the documentation and generate a mock out of supposed API docs.
• Always generate your own test data. Don't expect someone else to make the test data for you.