Help Center/ MapReduce Service/ User Guide/ MRS Cluster Planning/ Service Selection/ MRS Cluster Node Types
Updated on 2024-09-23 GMT+08:00
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MRS Cluster Node Types

An MRS cluster consists of multiple ECSs. The system manages nodes in node groups based on specifications. Nodes in the same node group use same ECS specifications.

Nodes in a cluster can be classified into Master nodes, Core nodes, and Task nodes based on the roles of components deployed on the nodes.

Table 1 Cluster node types

Node Type

Functions

Master node

MRS cluster management node. OMS server is deployed on the node to manage and monitor the cluster.

After creating the MRS cluster, the node containing master1 in its name functions as the Master1 node, and the one with master2 in its name functions as the Master2 node.

You can log in to a Master node either using VNC on the ECS management console or using SSH. After logging in to the Master node, you can access other nodes without entering passwords.

The system automatically deploys the Master nodes in active/standby mode and supports the high availability (HA) feature for MRS cluster management. If the active management node fails, the standby management node switches to the active state and takes over services.

To determine whether the Master1 node is the active management node, see Checking MRS Active/Standby Management Nodes.

Core node

Work node of an MRS cluster. It processes and analyzes data and stores process data.

In the Nodes tab of the cluster details page, the nodes in the node group whose Node Type includes Core are Core nodes.

Task node

Compute node. When the compute resources of a cluster are insufficient, you can configure elastic scaling policies to increase nodes automatically.

In the Nodes tab of the cluster details page, the nodes in the node group whose Node Type is Task are Task nodes.

If only the NodeManager (Yarn) or Supervisor (Storm) role is deployed in a node group in addition to basic mandatory roles, this node group is a Task node group.

MRS cluster nodes support remote login. The following remote login methods are available:

  • GUI login: Use the remote login function provided by the ECS console to log in to the Linux CLI of the cluster node.
  • SSH login: Use a remote login tool like PuTTY to access Linux ECSs. You need to bind an EIP to the ECS first.

    Apply for and bind an EIP to a cluster node. For details, see Assigning an EIP .

    You can log in to the ECS using a key or password. For details, see Logging In to an MRS Cluster Node.

Parent topic: Service Selection