process-scheduler

Manage node workers.

Features:

• Schedule processes with crontab rules
• Concurrency rules
• Dependency rules

Installation

$ npm install --save process-scheduler

Usage

const Scheduler = require('process-scheduler');

var scheduler = new ProcessScheduler(config);
scheduler.on('change', handleChange);
scheduler.on('message', handleMessage);
scheduler.schedule(options);

config: general scheduler configuration:

• threads: the maximum number of threads that should be used. This can be a number or you can assign a number of threads per process type (see options). Giving a number is like assigning the number of threads to the default type.

options is an array of objects that have the following structure:

• id: identifies the process (mandatory)
• worker: the worker that the scheduler will fork (mandatory)
• type: type of process. Default is 'default'
• noConcurrency: an array of process ids with which this process should not be run concurrently
• deps: an array of process ids that should be triggered when this process is triggered. If the appropriate noConcurrency rule exists, the depenency processes will be executed only after this process has finished. The deps array can also nest an object with the options structure. scheduler.schedule will fail if circular dependencies are detected.
• cronRule: a cron rule for executing the process. If not given the process is triggered once immediatly. See node-schedule for accepted input.
• immediate: true or false weather to execute the process once immediately or not. If undefined the process is executed immediately only if no cronRule is given
• retryTimeout: timeout in seconds after which the process should be restarted in case of failure

Events:

• change: notifies a change of status. An object with the follwing structure is passed:
  • id: id of the process configuration that launched the process
  • pid: the id of the process that updated its status
  • status: Possible status are queued, running, success, error
  • message: the error message if status is error.
• message: notifies that process has sent a message. The message sent by the process is in the data property
  • id: id of the process configuration that lanuched the process
  • pid: id of the process that sent a message
  • data: data sent by the process

License

MIT