How To Fix WRF_REF401 - No system resources available for parallel processing! -> Serialisation!

SAP Error Message - Details

• Message type: E = Error

• Message class: WRF_REF - Messages from References for Materials Without History

• Message number: 401

• Message text: No system resources available for parallel processing! -> Serialisation!

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message WRF_REF401 - No system resources available for parallel processing! -> Serialisation! ?

  The SAP error message WRF_REF401 indicates that there are no system resources available for parallel processing, leading to serialization. This typically occurs in the context of SAP's Advanced Planning and Optimization (APO) or other modules that require parallel processing capabilities.
  Cause:
  
  Resource Limitations: The system may be running out of available resources (CPU, memory, etc.) to handle parallel processing requests. This can happen if there are too many concurrent processes or if the system is under heavy load.
  Configuration Issues: The system may not be configured optimally for parallel processing. This includes settings related to the number of parallel processes allowed or the configuration of background jobs.
  Locks and Contention: There may be locks on certain resources that prevent parallel processing from occurring, leading to serialization.
  System Performance: If the system is experiencing performance issues, it may not be able to allocate resources for parallel processing effectively.
  
  Solution:
  
  Monitor System Resources: Use transaction codes like SM50 or SM66 to monitor the active processes and check for resource bottlenecks. Look for long-running jobs or processes that may be consuming excessive resources.
  Adjust Parallel Processing Settings: Review and adjust the settings for parallel processing in the relevant configuration areas. This may involve increasing the number of allowed parallel processes or optimizing job scheduling.
  Optimize Background Jobs: Check for any background jobs that may be running concurrently and consuming resources. Consider staggering their execution times to reduce contention.
  Increase System Resources: If the system is consistently running out of resources, consider upgrading the hardware or optimizing the system configuration to better utilize existing resources.
  Check for Locks: Use transaction SM12 to check for any locks that may be causing serialization. If locks are found, investigate the processes holding them and resolve any issues.
  Review System Logs: Check the system logs (transaction SM21) for any additional error messages or warnings that may provide more context about the issue.
  
  Related Information:
  
  SAP Notes: Search for relevant SAP Notes that may address this specific error or provide guidance on optimizing parallel processing in your version of SAP.
  Performance Tuning: Consider engaging in performance tuning activities to improve overall system performance, which can help alleviate resource constraints.
  SAP Community: Engage with the SAP Community forums to see if other users have encountered similar issues and what solutions they have implemented.
  
  If the problem persists after trying the above solutions, it may be beneficial to consult with your SAP Basis team or reach out to SAP support for further assistance.