Isolating a Host

Scenario

If a host is abnormal or faulty and cannot provide services or affects the cluster performance, you can remove the host from the available node in the cluster temporarily so that the client can access other available nodes.

Only non-management nodes can be isolated.

Impact on the System

• After a host is isolated, all role instances on the host will be stopped, and you cannot start, stop, or configure the host and all instances on the host.
• For some services, after a host is isolated, some instances on other nodes do not work, and the service configuration status may expire.
• After a host is isolated, statistics about the monitoring status and indicator data of the host hardware and instances on the host cannot be collected or displayed.
• Retain the default SSH port (22) of the target node. Otherwise, the task described in this section will fail.

Procedure

1. Log in to FusionInsight Manager.
2. Click Hosts.
3. Select the check box of the host to be isolated.
4. Select Isolate from the More drop-down list.

   In the displayed dialog box, enter the password of the current login user and click OK.

5. In the displayed confirmation dialog box, select "I confirm to isolate the selected hosts and accept possible consequences of service faults." Click OK.

   Wait until the message "Operation succeeded" is displayed, and click Finish.

   The host is successfully isolated and Running Status is Isolated.

6. Log in to the isolated host as user root and run the pkill -9 -u omm command to stop the processes of user omm on the node. Then run the ps -ef | grep 'container' | grep '${BIGDATA_HOME}' | awk '{print $2}' | xargs -I '{}' kill -9 '{}' command to find and stop the container process.
7. Cancel the isolation status of the host before using the host if you have rectified the host exception or fault.

   On the Hosts page, select the isolated host and choose More > Cancel Isolation.

   

   After the isolation is canceled, all role instances on the host are not started by default. To start role instances on the host, select the target host on the Hosts page and choose More > Start All Instances.