Graceful shutdown

As explained in Elixir in Action, Third Edition

Graceful termination is the controlled shutdown of a process that allows it to perform final cleanup before exiting.

Graceful shutdown terminates a process or supervision subtree in a controlled way, allowing final cleanup before exit. A supervisor asks children to stop, and nested supervisors propagate termination through their own trees. section 9.1.6

Apply graceful shutdown with these operational boundaries:

• Enable exit trapping in a GenServer during init/1 when cleanup must run; graceful termination then invokes terminate/2. section 9.1.6
• Set the child specification's shutdown option to a millisecond timeout, :infinity, or :brutal_kill. section 9.1.6
• Expect forceful termination when cleanup exceeds the configured timeout; the default is 5,000 milliseconds for workers and :infinity for supervisors. section 9.1.6

A cleanup-aware worker

Configure a GenServer to trap exits from init/1, then place final cleanup in terminate/2. Its supervisor can wait for that cleanup with shutdown: 5_000, wait indefinitely with :infinity, or skip the graceful phase with :brutal_kill. section 9.1.6

Figure 9.4 Supervision tree

Trace how termination flows from a top-level supervisor through its immediate children and nested supervision subtrees. section 9.1.6

How Elixir in Action, Third Edition covers it

How deep it goes

Explains propagation, GenServer callbacks, exit trapping, timeout choices, and forceful termination boundaries.

Examples

Uses a top-level supervisor, nested supervisor trees, GenServer terminate/2, and shutdown values including 5_000, :infinity, and :brutal_kill.

What it assumes

Assumes supervision trees, GenServer callbacks, child specifications, and process exit signals.

What you can do after

Operate/configure supervised workers with cleanup callbacks and bounded, indefinite, or immediate shutdown behavior.

How it connects

Connects supervision trees, GenServer, child specifications, exit trapping, and exit signals.

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Also explained in

• 

  liveBookmanning.com
  Kubernetes for DevelopersA graceful shutdown is an orderly process termination that stops accepting new work and allows in-progress work to finish.
• 

  liveBookmanning.com
  Kubernetes in Action, Second EditionA graceful shutdown is an orderly termination procedure that stops accepting new work and allows in-progress work to complete before exit.
• 

  liveBookmanning.com
  Go in Practice, Second EditionA graceful shutdown is an orderly termination procedure that allows active work and resources to be completed or released before a service stops.

Compare how 4 books explain graceful shutdown →

Related concepts

• termination grace periodconfigured by · A termination grace period is the time Kubernetes allows a Pod's containers to shut down gracefully before forcibly terminating them.
• signaluses · An operating-system signal is an asynchronous notification delivered to a process to report an event or request handling.

This explainer was generated by Manning's knowledge graph from the text of Elixir in Action, Third Edition. The section links point to the parts of the book it draws on.