`module HealthChecker`

A health checker for managed services.

Definitions

`def health_checker(instance, timeout = @evaluator.health_check_timeout, parent: Async::Task.current, &block)`

Start the health checker.

If a timeout is specified, a transient child task will be scheduled which will mark the instance as healthy, sleep for half the health check duration (so that we guarantee that the health check runs in time), and then yield the instance if a block is given. This repeats indefinitely.

If a timeout is not specified, the instance is marked as healthy immediately and no task is created. Any block given is ignored.

Signature

parameter　instance　Object: The service instance to check.
parameter　timeout　Numeric: The timeout duration for the health check.
parameter　parent　Async::Task: The parent task to run the health checker in.
yields　{|instance| ...}: If a block is given and a timeout is specified, it will be called with the service instance after each sleep interval.

Implementation

def health_checker(instance, timeout = @evaluator.health_check_timeout, parent: Async::Task.current, &block)
	if timeout
		parent.async(transient: true) do
			while true
				instance.healthy!
				
				sleep(timeout / 2.0)
				
				if block_given?
					yield(instance)
				end
			end
		end
	else
		instance.healthy!
	end
end