Starting and stopping Hadoop services

Sometimes it is necessary to stop the Hadoop services to allow for administration on these servers, such as operating system updates, back-ups, or virtual machine (VM) snapshots. Some administrators prefer to take snapshots with all servers powered off.

Procedure

To stop Hadoop services:

  1. Log into the Ambari console (admin/admin is the default ID and password): 
    https://ambari.host.com:8081
  2. In the left pane, click Actions > Stop All.
  3. Wait approximately 5 to 15 minutes for all services to stop.
  4. Perform maintenance tasks, as necessary, on all VMs or physical servers running Hadoop software. For example, you can take a full backup or vmware snapshot, update the operating system via yum update -y, or add memory.

To restart Hadoop services:

  1. After the VMs or servers are up and running, ensure that the Ambari server is started. After the operating system starts that contains the Ambari server, Ambari is configured to automatically start up. Log in to the Ambari console and select Start All.
  2. After 5 to 15 minutes, all of the HDP services are started and the system is fully operational again.