This is the documentation for Cloudera 5.2.x.
Documentation for other versions is available at Cloudera Documentation.

Starting, Stopping, and Restarting Services

Starting and Stopping Services

It's important to start and stop services that have dependencies in the correct order. For example, because MapReduce has a dependency on HDFS, you must start HDFS before starting MapReduce. The Cloudera Management Service and Hue are the only two services that do not have a dependency on other services; although you can start and stop them at anytime, their preferred order is shown in the following procedures.

The Cloudera Manager cluster actions start and stop services in the correct order. To start or stop all services in a cluster, follow the instructions in Starting, Stopping, Refreshing, and Restarting a Cluster.

Starting a Service on All Hosts

  1. On the Home page, click to the right of the service name and select Start.
  2. Click Start that appears in the next screen to confirm. When you see a Finished status, the service has started.

The order in which to start services is:

  1. Cloudera Management Service
  2. Zookeeper
  3. HDFS
  4. Solr
  5. Flume
  6. HBase
  7. KS_Indexer
  8. YARN
  9. Hive
  10. Impala
  11. Oozie
  12. Sqoop
  13. Hue
  Note: If you are unable to start the HDFS service, it's possible that one of the roles instances, such as a DataNode, was running on a host that is no longer connected to the Cloudera Manager Server host, perhaps because of a hardware or network failure. If this is the case, the Cloudera Manager Server will be unable to connect to the Cloudera Manager Agent on that disconnected host to start the role instance, which will prevent the HDFS service from starting. To work around this, you can stop all services, abort the pending command to start the role instance on the disconnected host, and then restart all services again without that role instance. For information about aborting a pending command, see Aborting a Pending Command.

Stopping a Service on All Hosts

  1. On the Home page, click to the right of the service name and select Stop.
  2. Click Stop that appears in the next screen to confirm. When you see a Finished status, the service has stopped.

The order in which to stop services is:

  1. Hue
  2. Sqoop
  3. Oozie
  4. Impala
  5. Hive
  6. YARN
  7. KS_Indexer
  8. HBase
  9. Flume
  10. Solr
  11. HDFS
  12. Zookeeper
  13. Cloudera Management Service

Restarting a Service

It is sometimes necessary to restart a service, which is essentially a combination of stopping a service and then starting it again. For example, if you change the hostname or port where the Cloudera Manager is running, or you enable TLS security, you must restart the Cloudera Management Service to update the URL to the Server.
  1. On the Home page, click to the right of the service name and select Restart.
  2. Click Start that appears in the next screen to confirm. When you see a Finished status, the service has restarted.

To restart all services, use the restart cluster action.