bean

bean is a Rebar3 plugin that automatically generates a supervision tree based on dependencies between processes. With this plugin, you can automatically generate a supervision tree that satisfies the following requirements simply by running this:

• The number of processes restarted at one time is minimal.
• All processes that depend on the terminated process are restarted.

Dependencies between processes are defined as the directions of communication between processes. For example, if process $p_1$ sends a message to process $p_2$, then "$p_2$ is dependent on $p_1$".

Use

Add this plugin to your rebar.config:

{plugins, [
    {bean, {git, "https://github.com/ajfAfg/bean.git", {tag, "0.1.0"}}}
]}.

Then just call the plugin directly in an existing application:

$ rebar3 bean
===> Fetching bean
===> Compiling bean
<Plugin Output>

See the demo project for a complete example of this plugin.

Specifications

• The supervision tree supervise the processes defined under the floor of src directory.
• The supervisor source codes are output to src/bean directory.
• The name of the root in the supervision tree is bean.
• Supported restart strategies are one_for_one, one_for_all, and rest_for_one only.
  • i.e. simple_one_for_one is not supported.

Limitations

Currently, bean has the following limitations:

• Only supports gen_server processes.
• Only gen_server:call/2,3 and gen_server:cast/2 communications are supported.
• Extractable communications are only those at the top level of the scope of each callback function of the module that implements gen_server.
  • It is also assumed that the first argument of each communication function is a literal representing the name of the gen_server.

More information

The supervision tree generation algorithm implemented in this plugin is proven to output a certain optimal tree. In addition, experimental results show that the algorithm is fast enough for many realistic cases, although it takes the worst-case exponential time. See the master's thesis "Automatic Generation of an Optimal Supervision Tree in Erlang" for details.

TODO: Add the link to the thesis when it is published.