theine¶

Theine is a Rails application pre-loader designed to work on JRuby. It is similar to Zeus, Spring and Spork. The problem with Zeus and Spring is that they use fork which doesn’t work on JRuby.

An example:

time rails runner "puts Rails.env"
48.31s user 1.96s system 242% cpu 20.748 total  # normal
time theine runner "puts Rails.env"
0.12s  user 0.02s system 32%  cpu 0.449  total  # Theine

Installing¶

You need to install screen on your system. For example on Ubuntu:

sudo apt-get install screen

Then install the gem.

gem install theine2

Upgrading¶

If you want to use CRuby for the client, you will probably need to re-run theine_set_ruby after upgrading.

Using¶

Start up the theine server in the root of your Rails project:

theine_server

or

theine_start for a detached process

Stopping the server (this only works if the server was started with theine_start)

theine_stop

You can also add –debug mode so that the spawned workers will be running in debug mode (debug mode is ignored if silent is set to true):

theine_server --debug

Then run any rails command using theine (don’t use bundle exec):

#Rails commands
theine runner "puts 'Hello world'"
theine server
theine console

#Rake, rspec, cucumber
theine rake db:migrate
theine rspec spec
theine cucumber

Configuration¶

Theine will look for a .theine file in your Rails app’s root directory and in your home directory. Both files are loaded if they exist, the one in your Rails app will overwrite settings from your home.

Example .theine file (YAML):

base_port: 11000
max_port: 11100
min_free_workers: 2
spawn_parallel: true
silent: true

base_port and max_port¶

The Theine server will use the base_port TCP port. Workers use base_port + 1 to max_port TCP ports. Use this setting if you need to run multiple Rails apps at the same time (use a different base_port for each).

min_free_workers¶

The minimum amount of workers that Theine should try to keep around. If you set this to 2 for example, once Theine has loaded 2 workers, you can execute two commands immediately. When you execute a third command, you will have to wait until Theine has spawned new workers. Theine will spawn a new worker as soon as you execute a command.

spawn_parallel¶

When set to true, Theine will start min_free_workers all at once. When set to false, it will start one worker first, and when it is loaded, it will start the next worker. When false, the first worker should start just a little bit faster. If you have a high number of min_free_workers then I recommend setting this to false.

silent¶

When set to true, Theine will start in silent mode. This mode gives no output to the shell and is perfect for using thiene_server & for a detached process. This is especially helpful in docker environments when you cannot have multiple shells open without tmux. recommend false for non docker workflows.

Speed up Theine¶

If you are using RVM or rbenv, you can tell theine to use Ruby 2.6 to run the client, which will make the Theine client start much faster.

If you have any problems in this mode, please revert back to using the same Ruby for the client.

Tell Theine to use CRuby for the client¶

Figure out where your Ruby 2.6.5 binary is:

$ rvm ruby-2.6.5 do which ruby
/Users/mrbrdo/.rvm/rubies/ruby-2.6.5-p114/bin/ruby

Then where you plan to use Theine, do:

$ rvm use jruby
$ theine_set_ruby /Users/mrbrdo/.rvm/rubies/ruby-2.6.5-p114/bin/ruby

Enjoy mega fast client:

time theine runner "puts 'hello world'"
0.12s user 0.02s system 30% cpu 0.470 total

Using with Foreman¶

Theine works with Foreman:

theine_server: theine_server
server: rails server

If you have problems, try adding theine to your Gemfile. If you want to use the theine client in foreman, you should use theine_current_ruby because Foreman uses bundle exec. But there is no point in doing that, since theine needs to spawn a process for each command anyway, so there is no benefit in comparison to just running the command (like rails server) directly.

Using with Docker¶

See Sample docker setup

How it works¶

Theine’s server spawns processes in the background that load your Rails application. When you run a command through theine, it will be executed in one of these pre-loaded processes. I used to do IO redirection (similarly to pry-remote) but it ended up being very unreliable, so now I am using screen to take care of this. After your command is done, the process will exit. When you run a new command, it will run in another pre-loaded process.

Theine will automatically spawn additional processes as needed.

The client (theine command) does not need to run on JRuby (or the same Ruby that you use in your Rails application), because it is only used to connect to the server, all the code is then actually executed on the server.