Events are records of certain occurrences in the system and are very useful to track the different operations running on the cluster. Several events are configured by default when Cloudera Manager is installed.
All events in the cluster are managed by the Event Server component of Cloudera Manager. To view the events, navigate to Diagnostics | Events from the Cloudera Manager toolbar. The following is the screenshot of the Events page:
The preceding screenshot shows one event for the HDFS service that is part of the node1.hcuster
host and the datanode (node1) role. The screenshot also shows the details of the alert that is displayed when you click on the Expand link. To close the details, you can use the Collapse link.
Search filters can also be applied to perform more advanced searches. Click on the Add a filter hyperlink to add filters as shown in the following screenshot:
To open up the datanode instance, click on the View button. The following screenshot shows the datanode (node1) instance that corresponds to the event:
To view the logfile for this datanode, that is, datanode (node1), click on the Log File link to open the Logs search screen as shown in the following screenshot:
Alerts are messages that are configured to be triggered by an event. Alerts are configured to inform the occurrence of events that need special attention.
The following are the steps to configure an event. For this example, we will configure an event to monitor HDFS free space:
For this illustration, let's update the values 25% and 20% for the Warning and Critical events respectively, as shown in the following screenshot:
The following screenshot shows the event generated when the free space on HDFS is below the set critical threshold of 20 percent:
You will observe that the event is labeled as Alert. This is because the HDFS service is configured to alert us if the service's status becomes bad.
The following alert types can be configured from Cloudera Manager:
Administrators would want to be alerted of certain events by e-mail rather than having to check the Events page for alerts and events. The following are the steps to configure the alert delivery by an e-mail:
In this chapter, we only covered the basics of monitoring, events, and alerts. Cloudera documentation provides an in-depth description of the various options available for monitoring the entire cluster and can be found at http://www.cloudera.com/content/cloudera-content/cloudera-docs/CM5/latest/Cloudera-Manager-Diagnostics-Guide/Cloudera-Manager-Diagnostics-Guide.html.
3.138.172.130