keel

README

Keel

1. Glossary

• Task: A task or job entity managed and executed by Keel. There are 3 types of task: CronTask, DelayTask and UserTask.
  • CronTask: A task or job being executed periodically, like Crontab in Linux.
  • DelayTask: A onetime task or job that will be executed later after creation. For instance, a task that cancels unpaid orders created 30 minutes ago.
  • UserTask: A task or job that is not executed either periodically or in the near future. Say you are going to build an application processing customers' media resources in background, such a process can be seen as UserTask, it is executed right after previous one finishes.
    • TaskUid: The user-provided unique identifier for an UserTask, must be unique under a Tenant.
• TaskRun: A record holding Task execution status, result, error and other details, created everytime a Task is executed.
• Tenant: An entity representing a customer, a work team and so on. Keel schedules tasks per each tenant.
  • TenantUid: The user-provided unique identifier for a Tenant, must be unique across all tenants.
• Zone: Available zone. Tenants must be unique across multiple zones.
• ResourceQuota: Resource usage limit of a Tenant, e.g. CPU, memory, GPU, storage, concurrency or custom workload figure.
• Scheduler: The process that handles task scheduling, but does not execute tasks. There might be more than one Scheduler running but only one Scheduler (the leader) can dispatch tasks at one time.
• Worker: The process that executes tasks assigned by Scheduler.