Shutdown and Restart Meridian
This section provides an example of the order to follow when shutting down and restarting a sample Meridian system: Meridian core layer, persistence and messaging layer, and database layer.
Note that restarting the whole stack is rare. Usually, the Meridian core is restarted only to apply configuration changes, or to run upgrades. A core restart usually takes less than 5 minutes, but can take longer depending on the configuration. The Minion and Sentinel components restart more quickly.
When shutting down the Meridian core, there will be no notifications, alarms, outage detection, performance data collection, thresholding, or flows. After restarting, there will be gaps in your performance graphs spanning the shutdown time. |
Restarting components in the persistence and messaging layer normally happens only for upgrades or catastrophic failures. Exercise caution with restarting components in this layer, since there is the risk of data loss.
The steps below are illustrative for a sample Linux setup. Your Meridian environment may be different. Documenting procedures for each setup is beyond the scope of this guide. You must be root to run the commands listed below. |
Shutdown
Shut down Meridian components in the following order:
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Dashboard applications, such as Grafana and Kibana.
systemctl stop grafana-server systemctl stop kibana
-
The Meridian core application (core, Sentinel, Minion), in any order.
-
Turn off notifications:
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Log in to the Meridian web UI.
-
Click the gear symbol at the top-right of the page.
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Under Event Management, toggle Notification Status Off and click Update.
-
-
Access the Meridian system via CLI (putty, SecureCRT, and so on).
-
Use the
sudo su -
command to become a root user. -
Type the following commands:
systemctl stop opennms systemctl stop minion systemctl stop sentinel
-
-
Persistence and messaging components (PostgreSQL, Cassandra, Kafka, and so on), in any order:
systemctl stop postgresql-12 systemctl stop cassandra systemctl stop elasticsearch
Neither Kafka nor Zookeeper has systemd definitions. The processes are controlled based on how they were installed. This is beyond the scope of this guide. |
Restart
Restart components in the following order:
-
Persistence and messaging components (PostgreSQL, Cassandra, Kafka, and so on), in any order:
systemctl start postgresql-12 systemctl start cassandra systemctl start elasticsearch
-
The Meridian core application (core, Sentinel, Minion), in any order:
systemctl start opennms systemctl start minion systemctl start sentinel
-
Turn on notifications:
-
Log in to the Meridian web UI.
-
Click the gear symbol at the top-right of the page.
-
Under Event Management, toggle Notification Status On and click Update.
-
-
-
Dashboard applications (Grafana, Kibana, and so on):
systemctl start grafana-server systemctl start kibana
You can restart dashboard applications at any time, but they will not show any useful information until all components in the persistence and Meridian layers have started. |