fettle

v1.0.0

fettle v1.0.0 Fettle.Runner View Source

Runs a health check periodically.

The start_link/4 function is called by the Fettle.RunnerSupervisor to start the server, passing the check spec, and Checker module to run.

When a check is scheduled to run, the server spawns the check function in a separate, monitored process, which will send the result back to the runner as a Fettle.Checker.Result.

The first check execution is scheduled after an initial delay (:initial_delay_ms), then the check is scheduled to run :period_ms after completion of the previous check. i.e. the period does not include the time it takes to actually run the check, just the time between completions (or time-outs); effectively the period defines the maximum rate that a check will run.

If a timeout (:timeout_ms) occurs before a result is received, the check enters error status, and the spawned checker process is killed by the Runner.

Results are forwarded to the Fettle.ScoreBoard process.

See also

Link to this section Summary

Types

checker_init()
t()

runner state

Functions

start_link(config, spec, checker_init, opts)

start the runner for the given check

Link to this section Types

Link to this type checker_init() View Source 
checker_init() :: {checker :: module(), init_args :: any()}
Link to this type t() View Source 
t() :: %Fettle.Runner{
  checker_fun: function(),
  checker_state: any(),
  id: String.t(),
  period_ms: integer(),
  result: Fettle.Checker.Result.t(),
  scoreboard: atom(),
  task: {pid(), reference()} | nil,
  timeout_ms: integer()
}

runner state

Link to this section Functions

Link to this function start_link(config, spec, checker_init, opts) View Source 
start_link(
  config :: Fettle.Config.t(),
  spec :: Fettle.Spec.t(),
  checker_init :: checker_init(),
  opts :: Keyword.t()
) :: GenServer.on_start()

start the runner for the given check.