How To Fix TN404 - No semaphore available -> Status is not set

SAP Error Message - Details

• Message type: E = Error

• Message class: TN - Support Package Manager (SPAM) Messages

• Message number: 404

• Message text: No semaphore available -> Status is not set

Self-Explanatory Message

Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of messages in the SAP system have a message text, however this is frequently insufficient to comprehend or resolve the problem.

To make things easier, more detailed information is frequently added to describe the issue, how to fix it, and the necessary steps or configuration modifications.

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Smart SAP Assistant

• What is the cause and solution for SAP error message TN404 - No semaphore available -> Status is not set ?

  The SAP error message TN404 "No semaphore available -> Status is not set" typically indicates an issue related to the transport management system (TMS) in SAP. This error occurs when the system is unable to acquire a semaphore, which is a synchronization mechanism used to control access to shared resources in a concurrent system.
  Causes:
  
  Semaphore Limit Reached: The maximum number of semaphores that can be created has been reached. This can happen if there are too many transport requests or processes running simultaneously.
  System Configuration Issues: Incorrect configuration of the transport management system or the underlying operating system can lead to semaphore allocation issues.
  Resource Exhaustion: The server may be running low on resources, such as memory or process limits, which can prevent the creation of new semaphores.
  Operating System Limits: The operating system may have limits on the number of semaphores that can be created, which can be configured in the system settings.
  
  Solutions:
  
  
  Check Semaphore Limits: Review the semaphore limits set in the operating system. For Unix/Linux systems, you can check the semaphore settings in the /etc/sysctl.conf file or by using the ipcs -s command. Increase the limits if necessary.
  Example commands to check and set semaphore limits:
  ipcs -s  # Check current semaphore settings
  sysctl -a | grep sem  # Check semaphore parameters
  
  
  Restart Transport Directory: Sometimes, restarting the transport directory can help clear up semaphore issues. You can do this by stopping and starting the transport directory service.
  
  
  Check for Stuck Processes: Use system monitoring tools to check for any stuck or zombie processes that may be holding onto semaphores. Terminate any unnecessary processes.
  
  
  Review Transport Configuration: Ensure that the transport configuration in the TMS is correct. Check the transport routes and ensure that all systems are properly connected.
  
  
  Increase System Resources: If the server is low on resources, consider increasing the available memory or CPU resources.
  
  
  Consult SAP Notes: Check the SAP Support Portal for any relevant SAP Notes that may address this specific error. There may be patches or updates that can resolve the issue.
  
  
  Related Information:
  
  SAP Transport Management System (TMS): Understanding how TMS works and its configuration can help in troubleshooting transport-related issues.
  Operating System Documentation: Familiarize yourself with the semaphore management in your specific operating system (e.g., Linux, AIX, Windows).
  SAP Community and Forums: Engaging with the SAP community can provide insights and solutions from other users who may have faced similar issues.
  
  If the problem persists after trying the above solutions, it may be necessary to contact SAP support for further assistance.