How do I restart a service in Amazon EMR?

Short description

The process for restarting a service differs depending on which Amazon EMR release version you have. Use the resolution steps that match your use case.

Resolution

Amazon EMR 5.30.0 and later release versions

1.    Connect to the primary node with SSH.

2.    List all running services:

systemctl --type=service

3.    To list a specific service, run a command similar to the following. For example, to list the Zeppelin service:

systemctl --type=service | grep -i zeppelin

Example output:

zeppelin.service  loaded active running Zeppelin

4.    To see a detailed status report for a specific service:

sudo systemctl status zeppelin

Example output:

zeppelin.service - Zeppelin
   Loaded: loaded (/etc/systemd/system/zeppelin.service; enabled; vendor preset: disabled)
   Active: active (running) since Tue 2020-04-21 18:26:53 UTC; 4min 59s ago
  Process: 25719 ExecStart=/usr/bin/su -s /bin/bash zeppelin -c cd /var/lib/zeppelin && /usr/lib/zeppelin/bin/zeppelin-daemon.sh --config '/etc/zeppelin/conf' start (code=exited, status=0/SUCCESS)
 Main PID: 25749 (java)
    Tasks: 0
   Memory: 4.0K
   CGroup: /system.slice/zeppelin.service
           25749 /etc/alternatives/jre/bin/java -Dfile.encoding=UTF-8 -Xms1024m -Xmx1024m -XX:MaxPermSize=512m -Dlog4j.configuration=file:///etc/zeppelin/con...

5.    Stop the service:

Note: You must use the stop and start commands in the following steps. Don't use the restart command.

sudo systemctl stop zeppelin

6.    Verify that the service is stopped:

sudo systemctl status zeppelin

7.    Start the service:

sudo systemctl start zeppelin

8.    Verify that the service is running:

sudo systemctl status zeppelin

Amazon EMR 4.x-5.29.0 release versions

1.    Connect to the primary node using SSH.

2.    List all running services:

initctl list

3.    Run the following command to stop the service. Replace "hadoop-yarn-resourcemanager" with the service that you want to restart.

Note: You must use the stop and start commands in the following steps. Don't use the restart command.

sudo stop hadoop-yarn-resourcemanager

4.    Wait a few seconds, and then start the service:

sudo start hadoop-yarn-resourcemanager

5.    Verify that the process is running:

sudo status hadoop-yarn-resourcemanager

Amazon EMR 2.x-3.x release versions

1.    Connect to the primary node using SSH.

2.    List all running services:

ls /etc/init.d/

3.    Run the following command to restart the service. Replace "hadoop-hdfs-namenode" with the service that you want to restart.

sudo /etc/init.d/hadoop-hdfs-namenode restart

4.    Verify that the process is running:

sudo /etc/init.d/hadoop-hdfs-namenode status

Related information

About Amazon EMR releases