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A rack server built upon vert.x, can be used as a vertx module
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Jubilee server

A rack application compatible http server built on Vertx3. Check out the demo application.

Why another rack server?

"Vert.x is a lightweight, high performance application platform for the JVM that's designed for modern mobile, web, and enterprise applications." - site

By using Vertx, jubilee inherent advantages in terms of performance, and all the other cool features of Vertx:

Get started

Make sure you have JDK 8 and jruby 1.7.20+ installed.

bundle && bundle exec rake install

This is the development branch of jubilee, it uses the vertx 3.0 for a working version, please check out the 2.x branch.


Under the default setup, jubilee runs 4 instances of web servers, each with it's own jruby runtime, if you find that jubilee crashes or hangs with OutOfMemeoryError, please tune your JVM OPTS like this:

$ export JAVA_OPTS="-Xms1024m -Xmx2048m -XX:PermSize=512m -XX:MaxPermSize=512m"

If your OS memory is quite limited, please run jubilee with

$ jubilee -n 1

Event Bus

Event Bus is a pub/sub mechanism, it can be used from server to server, server to client and client to client, with the same API! You can use it to build living real time web application.


Assume necessary javascript files are loaded in the page (they can be found here), start jubilee in a rack application with:

$ jubilee --eventbus eventbus

In one browser:

var eb = new vertx.EventBus("/eventbus");
eb.registerHandler("test", function(data){;

In another:

var eb = new vertx.EventBus("/eventbus");
eb.send("test", "hello, world");

In the previous tab it should print the greetings you just sent.

For more advanced examples, please checkout the chatapp.

Performance Tuning

If you're creating a lot of connections to a Jubilee(Vert.x) server in a short period of time, e.g. benchmarking with tools like wrk, you may need to tweak some settings in order to avoid the TCP accept queue getting full. This can result in connections being refused or packets being dropped during the handshake which can then cause the client to retry.

A classic symptom of this is if you see long connection times just over 3000ms at your client.

How to tune this is operating system specific but in Linux you need to increase a couple of settings in the TCP / Net config (10000 is an arbitrarily large number)

sudo sysctl -w net.core.somaxconn=10000
sudo sysctl -w net.ipv4.tcp_max_syn_backlog=10000

For other operating systems, please consult your operating system documentation.


All kinds of contributions are welcome.

File an issue here if you encounter any problems. Or if you prefer to fix by yourself:

  1. Fork it
  2. Create your feature branch (git checkout -b my-new-feature)
  3. Commit your changes (git commit -am 'Add some feature')
  4. Push to the branch (git push origin my-new-feature)
  5. Create new Pull Request




YourKit is kindly supporting Jubilee Server with its full-featured Java Profiler. YourKit, LLC is the creator of innovative and intelligent tools for profiling Java and .NET applications. Take a look at YourKit's leading software products: YourKit Java Profiler and YourKit .NET Profiler.

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