Nagios Network Analyzer - Graph Says "No Data Available"

Problem Description

The Source's graph in the summary tab of Network Analyzer says "No Data Available".

Resolution

This could mean one of many things. The fact that it is showing "No Data Available" means that the script that generates the graph is running. If the graph comes up empty or loads forever, this could be a sign that you are getting a 500 error. You would need to check the apache error log and find out why it was causing an error. This is much less likely than the "No Data Available" problem, so we will go in depth with this instead.

Troubleshooting the "No Data Available" error

There's a few reasons why no data is showing up in the graph.

• Data hasn't been aggregated yet

  • When a Source is collecting data, every 5 minutes it will aggregate the data and place it into the RRD file.

  • This means that for the first 5-10 minutes you may not see any data in your graph.

  • This is completely normal.

  • Data below the graph in the "Top 5 Talkers" section will begin to populate within 5 minutes if flow data is being properly sent.

• The nna user can't read the RRD data file

  • The RRD data file needs to have read write permissions for the "nna" user and "nnacmd" group.

  • The bandwidth.rrd file is located in /usr/local/nagiosna/var/<sourcename>/bandwidth.rrd

• Firewall or port settings are not set correctly

  • In order to receive flows you have to give the Source a port to listen on.

  • If you've set up port 5566 you need to make sure that incoming data is allowed in on this port.

  • If not, then you will never receive any flow data from your devices.

• nfcapd or sfcapd collector isn't running

  • When a Source is "online" from the web interface it really just means that nfcapd or sfcapd is running in the background ready to collect incoming data.

  • If you have access to the terminal, run:to see if there is a nfcapd process running for that source. The source name will be in the directory structure and the port should match.

    • ps aux | grep nfcapd

  • Sometimes the nfcapd process can get stuck or not start because the .pid file exists and cannot be removed on startup. The file is located in /usr/local/naigosns/var/<sourcename>/<port>.pid and will need owner read/write permissions and should be owned by the "nna" user and "nnacmd" group. This same process works for sfcapd if you're collecting sFlow instead of Netflow.

Final Thoughts

For any support related questions please visit the Nagios Support Forums at:

http://support.nagios.com/forum/