How To Fix CMS156 - Cache &1:&2:&3 Is Using an Undefined Host

SAP Error Message - Details

• Message type: E = Error

• Message class: CMS - KPro: Content Management Service

• Message number: 156

• Message text: Cache &1:&2:&3 Is Using an Undefined Host

What causes this issue?

The Customizing specifies that there is a cache (port &v2&, SSL port:
&v3&) on the host &v1&. However, the host &v1& is not defined in the
Customizing.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Procedure for System Administrators

Define the host &v1& in the Customizing (
<DS:TRAN.SCMSHO>Define host</>).

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message CMS156 - Cache &1:&2:&3 Is Using an Undefined Host ?

  The SAP error message CMS156, which states "Cache &1:&2:&3 Is Using an Undefined Host," typically occurs in the context of the SAP Cache Management System (CMS). This error indicates that a cache instance is trying to connect to a host that has not been defined or is not recognized by the system.
  Cause:
  
  Undefined Host Configuration: The host specified in the cache configuration is not defined in the system. This could be due to a typo in the host name or the host not being added to the system.
  Network Issues: There may be network connectivity issues preventing the system from recognizing the host.
  Configuration Changes: Recent changes in the system configuration may have removed or altered the host settings.
  Cache Instance Issues: The cache instance itself may not be properly configured or may have been corrupted.
  
  Solution:
  
  
  Check Host Configuration:
  
  Go to the configuration settings for the cache instance and verify that the host name is correctly defined.
  Ensure that the host is listed in the system and is reachable.
  
  
  
  Verify Network Connectivity:
  
  Use network tools (like ping or traceroute) to check if the host is reachable from the SAP system.
  Ensure that there are no firewall rules or network policies blocking access to the host.
  
  
  
  Update Cache Configuration:
  
  If the host has changed, update the cache configuration to point to the correct host.
  If the host is no longer needed, consider removing it from the cache configuration.
  
  
  
  Restart Cache Instances:
  
  Sometimes, simply restarting the cache instances can resolve temporary issues.
  
  
  
  Check SAP Notes:
  
  Look for any relevant SAP Notes that may address this specific error. SAP frequently updates their knowledge base with solutions for known issues.
  
  
  
  Consult Documentation:
  
  Review the SAP documentation for Cache Management to ensure that all configurations are set up correctly.
  
  
  
  Related Information:
  
  SAP Support: If the issue persists after trying the above solutions, consider reaching out to SAP Support for further assistance.
  System Logs: Check the system logs for any additional error messages or warnings that may provide more context about the issue.
  Version Compatibility: Ensure that the version of SAP you are using is compatible with the cache configuration you have set up.
  
  By following these steps, you should be able to identify and resolve the issue related to the CMS156 error message.