Ozone replication manager's throttling of tasks

Learn about the different commands Ozone's Replication Manager (RM) schedules for throttling of tasks.

To protect the cluster from being overloaded with the RM tasks, it is important that a limited number of these tasks run on the cluster at any time. The load on datanodes can change over time and this impacts their speed at processing the tasks. In addition to throttling concurrent work, it is important that the RM, running inside SCM, does not queue too many tasks on the datanodes.

RM schedules the following types of commands which it throttles:
  • Replicate container commands

    Creates additional copies of a container to resolve replication issues and to allow nodes to be decommissioned safely.

  • Delete container replica commands

    Resolves over replication and also deletes containers in unexpected states.

  • EC reconstruction commands

    Recovers lost EC replicas. These are the most expensive commands.