Hostname Resolution Showing IP Instead of FQDN after upgrading SQL Server cartridge to 8.0 or higher (4382186)

After upgrading to a 8.0 or higher SQL Server cartridge, the “hostname” shown in Foglight (especially in the Global View dashboard) keeps using the IP address even though the user expects the short hostname to be displayed.

Foglight 8.0 introduced a new setting: monHostUseNslookup.

If monHostUseNslookup was disabled: The agent used the server’s internal name (like COMPUTERNAME) from SQL, so hostnames appeared as expected, but only if the environment was consistent.

If monHostUseNslookup was enabled: The agent tried to use DNS (nslookup) to resolve full hostnames.

• If DNS/reverse lookup was NOT working: Java could not find the hostname, so it fell back to showing the server’s IP address in the dashboard.
• In these cases, even after fixing DNS or host settings, you often had to clean up (delete and re-add) old IP-based objects in Foglight for the change to take effect. This made maintenance harder and more confusing.

Note: Reverse DNS must be configured to revolve correctly from the FglAM for the agent to display the FQDN (Fully Qualified Domain Name) in the Global View hosts column.

WORKAROUND

None

STATUS

Upgrade the SQL Server cartridge to version 8.1.0.21 (also known as HFIX-606 which is attached to this KB article for users logged into Supportlink) or higher (including 8.2.0.10) which. These versions give control with the monHostUseNslookup setting, so users can keep hostnames showing as expected, even if DNS is not set up.

• To see hostnames only, leave monHostUseNslookup turned off for each agent.
• To see FQDN or DNS-based names, enable the monHostUseNslookup setting.

The attached groovy scripts can be used to turn on the monHostUseNslookup value for all SQL Server agents already installed, and to list the current settings. Users must be logged into Supportlink to download the files.

Then clean up old/duplicate objects after upgrading to 8.1.0.21 or higher for this issue

• Remove any leftover host or agent objects in Foglight that were created when the agent was in the wrong mode (e.g., objects with the IP instead of the hostname). 
• Use Foglight’s "Object Cleanup" tool to search for and delete agent/host objects using unwanted IP addresses or duplicate hostnames.
• This ensures Foglight won’t display outdated or incorrect entries, and only new, properly-named objects are shown moving forward.
  
  

Note: if upgrading to 8.1.0.21, the cartridge must be deployed to all FglAMs after installing the cartridge. All database cartridges must also be upgraded to be at the 8.1 level.