How To Fix ICM521 - Memory Used of the HTTP Server Cache (in Percent)

SAP Error Message - Details

• Message type: E = Error

• Message class: ICM - Messages for ICM Monitor

• Message number: 521

• Message text: Memory Used of the HTTP Server Cache (in Percent)

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message ICM521 - Memory Used of the HTTP Server Cache (in Percent) ?

  The SAP error message ICM521 indicates that the memory used by the HTTP server cache has reached a certain threshold, which can lead to performance issues or even service interruptions if not addressed. This message is typically related to the Internet Communication Manager (ICM) in SAP systems, which handles HTTP requests.
  Cause:
  The ICM521 error is triggered when the memory usage of the HTTP server cache exceeds a predefined limit. This can happen due to several reasons:
  
  High Traffic: An increase in the number of HTTP requests can lead to higher memory consumption.
  Large Cache Size: If the cache size is set too large, it may consume more memory than available.
  Inefficient Cache Management: Poorly configured cache settings or inefficient caching strategies can lead to excessive memory usage.
  Memory Leaks: There may be underlying issues in the application or configuration that cause memory leaks.
  
  Solution:
  To resolve the ICM521 error, consider the following steps:
  
  
  Monitor Memory Usage: Use transaction codes like SM04 or ST06 to monitor memory usage and identify any spikes or trends.
  
  
  Adjust Cache Settings:
  
  Increase Cache Size: If the cache size is too small, consider increasing it. This can be done in the ICM configuration settings.
  Limit Cache Size: Conversely, if the cache is too large, you may want to limit it to prevent excessive memory usage.
  
  
  
  Optimize Cache Management:
  
  Review the caching strategy and ensure that only necessary data is cached.
  Implement cache expiration policies to remove stale data from the cache.
  
  
  
  Check for Memory Leaks: Investigate the application for potential memory leaks. This may involve reviewing custom code or third-party components.
  
  
  Restart ICM: In some cases, restarting the ICM can temporarily alleviate memory pressure, but this is not a long-term solution.
  
  
  System Resources: Ensure that the server has adequate resources (CPU, RAM) to handle the expected load.
  
  
  SAP Notes: Check for any relevant SAP Notes or patches that may address known issues related to memory management in the ICM.
  
  
  Related Information:
  
  ICM Configuration: The ICM can be configured using transaction RZ10 or RZ11 for profile parameters.
  Monitoring Tools: Use tools like SAP Solution Manager or other monitoring solutions to keep track of system performance and memory usage.
  Performance Tuning: Regularly review and tune the performance of your SAP system to ensure optimal operation.
  
  By following these steps, you should be able to address the ICM521 error and improve the performance of your SAP system's HTTP server cache.