Description

This article describes the procedure to change the time interval for Simple Network Management Protocol (SNMP) data collection in OpenNMS.

Symptoms

Customers sometimes need to have the graphs under Network Monitoring updated at specific time intervals rather than the default time interval. For Junos Space versions 12.3 and earlier, this default time interval is 300000 milliseconds. For Junos Space versions 13.1 and later, the default time interval is 900000 milliseconds for SNMP data collection.

Solution

WARNING: Decreasing the polling interval will increase the demand on system resources and might have a negative performance impact for the entire system.

Perform the following steps to modify the time interval for data collection:

  1. On the Junos Space server CLI, open the following file in test editor mode:

/opt/opennms/etc/collectd-configuration.xml

  1. Locate the following line:

package name="example1"

  1. Modify the value as specified below and save the file.

<service name="SNMP" interval="900000" user-defined="false" status="on">

to

<service name="SNMP" interval="300000" user-defined="false" status="on">   -- for 5 minutes

  1. Change the RRD step value (in seconds) in /opt/opennms/etc/datacollection-config.xml.

Modify the value from:

<rrd step="900">

to

<rrd step="300"> -- for 5 minutes

  1. Stop the OpenNMS services from the UI by navigating to Network Application Platform >> Administration >> Applications >> right-click Network Management Platform >> Manage Services >> Stop Network Monitoring.

  2. Navigate to /var/opennms/rrd/snmp/.

  3. Delete the . jrb files from here by running the following command:

    Warning: This will delete all the data in the OpenNMS database. This step is necessary whenever the OpenNMS polling interval is modified. 

    find /var/opennms/rrd/snmp/ -name "*.jrb" | xargs rm -f

  4. Start the OpenNMS services from the Junos Space UI by navigating to Network Application Platform >> Administration >> Applications >> right-click Network Management Platform >> Manage Services >> Start Network Monitoring.

This will change the time interval value for data collection.

Modification History

2022-08-11: Updated article with the current steps