Guides - Troubleshooting Longview

This guide discusses basic troubleshooting steps to help you diagnose and resolve any issues you may encounter while using Longview. If you’re experiencing problems with the Longview client, follow the steps outlined in this guide to help determine the cause.

Basic Diagnostics

1. Ensure that your system is fully updated.

   Note

   Longview requires Perl 5.8 or later.

2. Verify that the Longview client is running. Use the command that is appropriate for your distribution’s initialization system:

   Distributions with systemd

   sudo systemctl status longview

   Distributions without systemd

   sudo service longview status

   If the Longview client is not running, start it with the command appropriate for your distribution’s initialization system:

   Distributions with systemd

   sudo systemctl start longview

   Distributions without systemd

   sudo service longview start

   If the service fails to start, check Longview’s log for errors. The log file is located in /var/log/linode/longview.log.

Debug Mode

Restart the Longview client in debug mode for increased logging verbosity.

1. First stop the Longview client:

   Distributions with systemd

   sudo systemctl stop longview

   Distributions without systemd

   sudo service longview stop

2. Then restart Longview with the debug flag:

   sudo /etc/init.d/longview debug

3. When you’re finished collecting information, repeat the first two steps to stop Longview and restart it again without the debug flag.

   If Longview does not close properly, find the process ID and kill the process:

   ps aux | grep longview
   sudo kill $PID
   

Firewall Rules

If your Linode has a firewall, it must allow communication with Longview’s aggregation host at longview.linode.com (IPv4: 96.126.119.66). You can view your firewall rules with one of the commands below, depending on the firewall controller used by your Linux distribution:

• firewalld

  sudo firewall-cmd --list-all
  Note

  Review our Introduction to FirewallD on CentOS guide for more help with FirewallD.

• iptables

  sudo iptables -S
  Note

  Review our Control Network Traffic with iptables guide for more help with iptables.

• ufw

  sudo ufw show added
  Note

  Review our How to Configure a Firewall with UFW guide for more help with UFW.

If the output of those commands show no rules for the Longview domain (or for 96.126.119.66, which is the IP for the Longview domain), you must add them. A sample iptables rule that allows outbound HTTPS traffic to Longview would be the following:

iptables -A OUTPUT -p tcp --dport 443 -d longview.linode.com -j ACCEPT

Verify API key

The API key given in the Linode Cloud Manager should match that on your system in /etc/linode/longview.key.

1. In the Linode Cloud Manager, the API key is located in the Installation tab of your Longview Client instance’s detailed view.

2. SSH into your Linode. The Longview key is located at /etc/linode/longview.key. Use cat to view the contents of that file and compare it to what’s shown in the Linode Cloud Manager:

   cat /etc/linode/longview.key

   The two should be the same. If they are not, paste the key from the Linode Cloud Manager into longview.key, overwriting anything already there.

Cloned Keys

If you clone a Linode which has Longview installed, you may encounter the following error:

Multiple clients appear to be posting data with this API key. Please check your clients' configuration.

This is caused by both Linodes posting data using the same Longview key. To resolve it:

1. Uninstall the Longview agent on the cloned system.

   CentOS:

   sudo yum remove linode-longview

   Debian or Ubuntu:

   sudo apt-get remove linode-longview

   Other Distributions:

   sudo rm -rf /opt/linode/longview

2. Add a new Linode Longview Client instance. This will create a new Longview API key independent from the system which it was cloned from.

   Note

   The GUID provided in the Longview Client’s installation URL is not the same as the Longview API key.

3. Install the Longview Agent on the cloned Linode.

Contact Support

If you still need assistance after performing these checks, please open a support ticket.