How to enable verbose debug logs for cPanel's DNS clustering service, also known as dnsadmin

Introduction

If you find that you need to troubleshoot cPanel's DNS clustering, you may use the following steps to enable verbose debug logs for dnsadmin, which is our DNS clustering software.

Procedure

1. Login to WHM as the root user

2. Navigate to: "Home / Clusters / DNS Cluster"

3. Click on the "Pencil and form" icon under the "Actions" column for the cluster member that you would like to enable verbose logs for

4. Put a check next to the "Debug mode" option

5. Click the blue "Submit" button

6. Repeat the above 5 steps for each cluster member relationship that you would like to audit. Also keep in mind that you will usually want to do this both of the servers in each relationship in case the information you need is found on one server, but not the other.

7. Once debug mode has been enabled, you can tail the dns_admin log to see new log entries as they come in via SSH or Terminal as the root user:

tail -fn0 /usr/local/cpanel/logs/dnsadmin_log

8. With that tail command in place perform the steps required to reproduce the problem that you are having and then check the log on each server involved in the transaction.

9. If the problem is intermittent and you need to allow a significant time to pass, you may come back at a later time and view the log with the following command:

less /usr/local/cpanel/logs/dnsadmin_log

IMPORTANT: Debug mode generates a significantly larger amount of data as compared to normal dnsadmin logging. If you leave this mode on for any length of time, you should have disk usage monitoring in place on the server and check it regularly to be sure that the logs do not grow too quickly and consume too much disk space. On servers with extremely high DNS traffic, you should also pay attention to the %iowait and other disk I/O statistics closely to be sure that the additional I/O consumed by debug logs is not impacting the server in a negative way. You can learn more about what %iowait is with the following resource:

What is %IOWait in relation to the sar command and when should I be concerned?