For each alert, the out of the box Hadoop Nagios configuration file defines default values for the following Nagios directives:
- Warning threshold
The value that produces a warning alert.
- Critical threshold
The value that produces a critical alert.
- Check interval
The number of minutes between regularly scheduled checks on the host as long as the check does not change the state.
- Retry interval
The number of minutes between “retries” When a service changes state, Nagios can confirm that state change by retrying the check multiple times. This retry interval can be different than the original check interval.
- Maximum number of check attempts
The max number of retry attempts. Usually when the state of a service changes, this change is considered “soft” until multiple retries confirm it. Once the state change is confirmed, it is considered “hard”. Ambari Web displays hard states for all the Nagios Hadoop specific checks.
To change these default directive values, an administrator must:
Modify the configuration file,
/etc/nagios/objects/hadoop-services.cfg
See Configuring New Alerts For Hadoop for more information on the structure of this file.
Restart the Nagios service using following command as
rootuser:
service nagios restart