Important YARN Commands

Nixon Data Important YARN Commands

Important YARN Commands

Introduction

Yarn (Yet Another Resource Negotiator) is a resource management system for large-scale distributed systems, such as Hadoop. It provides a centralized platform for managing, scheduling and allocating resources for various big data processing tasks. In this article, we will discuss some of the important Yarn commands that are frequently used in big data processing.

Overview of Yarn

Yarn acts as an intermediary between the MapReduce application and the underlying cluster resources. It provides a flexible, multi-tenant architecture that enables multiple applications to run concurrently and share cluster resources such as CPU, memory, and storage. This helps to optimize resource utilization and minimize the risk of resource contention, making Yarn an essential tool for managing big data processing tasks.

Important Yarn Commands

  • yarn application –list
    • This command displays a list of all the applications that are currently running on the Yarn cluster. It provides information such as the application ID, name, queue, state, and progress.
  • yarn application –kill [application ID]
    • This command is used to kill a specific application running on the Yarn cluster. The application ID is used to identify the specific application that needs to be terminated.
  • yarn node –list
    • This command provides information about the nodes in the Yarn cluster, including the node ID, hostname, state, number of containers, and available resources.
  • yarn node –states [node ID]
    • This command provides information about the state of a specific node in the Yarn cluster, including the node ID, hostname, state, number of containers, and available resources.
  • yarn application –status [application ID]
    • This command provides detailed information about a specific application running on the Yarn cluster, including the application ID, name, queue, state, progress, and application-specific information.
  • yarn rmadmin –refreshQueues
    • This command is used to refresh the resource queues in Yarn. It can be used to add or remove queues, adjust queue properties, or update queue capacities.
  • yarn rmadmin –moveToQueue [application ID] [queue name]
    • This command is used to move a specific application to a different queue in Yarn. The application ID is used to identify the specific application that needs to be moved, and the queue name specifies the destination queue.

Top 30 Most Useful YARN Commands

  • yarn application -list:
    • Lists all the applications currently running on Yarn.
  • yarn application -kill [application ID]:
    • Kills the specified application with the provided ID.
  • yarn application -status [application ID]:
    • Shows the status of the specified application with the provided ID.
  • yarn node -list:
    • Lists all the nodes in the cluster.
  • yarn node -states [node ID]:
    • Shows the state of the specified node with the provided ID.
  • yarn queue -list:
    • Shows the list of all queues in the cluster.
  • yarn queue -showacls [queue name]:
    • Shows the access control list for the specified queue.
  • yarn queue -list-child-queues [queue name]:
    • Lists the child queues for the specified queue.
  • yarn logs -applicationId [application ID]:
    • Shows the logs of the specified application with the provided ID.
  • yarn rmadmin -refreshQueues:
    • Refreshes the queue configurations.
  • yarn rmadmin -refreshNodes:
    • Refreshes the node configurations.
  • yarn rmadmin -refreshUserToGroupsMappings:
    • Refreshes the user-to-group mappings.
  • yarn rmadmin -refreshSuperUserGroupsConfiguration:
    • Refreshes the super user group configuration.
  • yarn rmadmin -getGroups [user name]:
    • Shows the groups the specified user belongs to.
  • yarn rmadmin -transitionToActive [service ID]:
    • Transitions the specified service to the active state.
  • yarn rmadmin -transitionToStandby [service ID]:
    • Transitions the specified service to the standby state.
  • yarn application -submit [application file]:
    • Submits the specified application file to Yarn.
  • yarn application -movetoqueue [application ID] [queue name]:
    • Moves the specified application with the provided ID to the specified queue.
  • yarn node -all -list:
    • Shows a detailed list of all nodes in the cluster.
  • yarn node -list -all:
    • Same as yarn node -all -list
  • yarn node -list -states [node ID]:
    • Shows the state of the specified node with the provided ID.
  • yarn node -list -info [node ID]:
    • Shows detailed information about the specified node with the provided ID.
  • yarn node -list -diagnostics [node ID]:
    • Shows the diagnostics information for the specified node with the provided ID.
  • yarn node -list -metrics [node ID]:
    • Shows the metrics information for the specified node with the provided ID.
  • yarn rmadmin -printTopology:
    • Prints the cluster’s network topology.
  • yarn rmadmin -failover [–forcefence] [–forceactive] [–force standby]:
    • Fails over a ResourceManager from one node to another.
  • yarn rmadmin -getGroups [user name]:
    • Shows the groups the specified user belongs to.
  • yarn rmadmin -getQueueInfo [queue name]:
    • Shows the information of the specified queue.
  • yarn logs -applicationId [application ID] -nodeAddress [node address]:
    • Shows the logs of the specified application with the provided ID for the specified node address.
  • yarn logs -applicationId [application ID] -containerId [container ID]:
    • Shows the logs of the specified application with the provided ID

Conclusion

Yarn provides a powerful platform for managing big data processing tasks by enabling centralized resource management and allocation. The commands discussed in this article are some of the most important and frequently used Yarn commands in big data processing. By understanding these commands, big data engineers and administrators can effectively manage and optimize the performance of their big data processing tasks.