Help Center/ MapReduce Service/ User Guide (ME-Abu Dhabi Region)/ Connecting to Clusters/ Logging In to a Cluster/ Determining Active and Standby Management Nodes of Manager
Updated on 2022-02-22 GMT+08:00

Determining Active and Standby Management Nodes of Manager

This section describes how to determine the active and standby management nodes of Manager on the Master1 node.

Background

You can log in to other nodes in the cluster from the Master node. After logging in to the Master node, you can determine the active and standby management nodes of Manager and run commands on corresponding management nodes.

In active/standby mode, a switchover can be implemented between Master1 and Master2. For this reason, Master1 may not be the active management node for Manager.

Procedure

  1. Confirm the Master nodes of an MRS cluster.

    1. In the navigation tree of the MRS management console, choose Clusters > Active Clusters, select a running cluster, and click its name to switch to the cluster details page. View basic information of the specified cluster.
    2. On the Nodes tab page, view the node name. The node that contains master1 in its name is the Master1 node. The node that contains master2 in its name is the Master2 node.

  2. Determine the active and standby Manager management nodes.

    1. Remotely log in to the Master1 node. For details, see Logging In to an ECS.

      Master nodes support Cloud-Init. The preset username for Cloud-Init is root and the password is the one you set during cluster creation.

    2. Run the following commands to switch the user:

      sudo su - root

      su - omm

    3. Run the following command to identify the active and standby management nodes:

      For versions earlier than MRS 3.x, run the sh ${BIGDATA_HOME}/om-0.0.1/sbin/status-oms.sh command.

      For MRS 3.x or later: Run the sh ${BIGDATA_HOME}/om-server/om/sbin/status-oms.sh command.

      In the command output, the node whose HAActive is active is the active management node (mgtomsdat-sh-3-01-1 in the following example), and the node whose HAActive is standby is the standby management node (mgtomsdat-sh-3-01-2 in the following example).

      Ha mode
      double
      NodeName              HostName                      HAVersion          StartTime                HAActive             HAAllResOK           HARunPhase 
      192-168-0-30          mgtomsdat-sh-3-01-1           V100R001C01        2014-11-18 23:43:02      active               normal               Actived    
      192-168-0-24          mgtomsdat-sh-3-01-2           V100R001C01        2014-11-21 07:14:02      standby              normal               Deactived

      If the Master1 node to which you have logged in is the standby management node and you need to log in to the active management node, run the following command:

      ssh IP address of Master2 node