Monitors the command queue for pending commands and ensures processors are started as needed.

Overview

The InstanceMonitor is a GenServer responsible for periodically scanning the database for instances that have commands requiring processing. For each such instance, it ensures that an InstanceProcessor is running to handle those commands.

Responsibilities

• Periodically poll the database for instances with pending, failed, or timed-out commands.
• For each instance with processable commands, ensure an InstanceProcessor is started.
• Avoid starting duplicate processors for the same instance by checking the Registry.
• Use application configuration for poll interval (:poll_interval in :command_queue config).

Configuration

The poll interval can be set in your application config:

config :double_entry_ledger, :command_queue, poll_interval: 5_000

The default poll interval is 5,000 milliseconds (5 seconds) if not specified.

Process Supervision

This module is intended to be supervised as part of the command queue supervision tree.