Heroku Blog

We're very excited to announce official support for Clojure, going into public beta as of today. Clojure is the third official language supported by Heroku, and is available on the Cedar stack. Clojure is a Lisp-like functional programming language which runs on the Java Virtual Machine (JVM). It offers powerful concurrency primitives based on immutable data structures, with emphasis on composability and correctness. The Clojure community is vibrant and growing quickly. More about Clojure in a moment, but first: Clojure on Heroku in 2 minutes Create a project with three files: project.clj (defproject hello-world "0.0.1" :dependencies [[org.clojure/clojure "1.2.1"] [ring/ring-jetty-adapter "0.3.9"]])…

In 2006, I wrote Catapult: a Quicksilver-inspired command-line for the web. I deployed it to a VPS (Slicehost), then gave the URL out to a few friends. At some point I stopped using it, but some of my friends remained heavy users. Two years later, I got an email: the site was down. Logging into the server with ssh, I discovered many small bits of breakage: The app's Mongrel process had crashed and not restarted. Disk usage was at 100%, due to growth of logfiles and temporary session data. The kernel, ssh, OpenSSL, and Apache needed critical security updates. The…

Visibility and introspection capabilities are critical for managing and debugging real-world applications. But cloud platforms are often lacking when it comes to visibility. The magical black box is great when it "just works," but not so great when your app breaks and you can't look inside the box. Standard introspection tools used in server-based deployments — such as ssh, ps aux, top, tail -f logfile, iostat — aren't valid in a multi-tenant cloud environment. We need new tools, new approaches. Heroku's new runtime stack, Celadon Cedar, includes three powerful tools for visibility and introspection: heroku ps, heroku logs, and heroku…