How To Fix ICM606 - Small hit ratio in ICM server cache

SAP Error Message - Details

• Message type: E = Error

• Message class: ICM - Messages for ICM Monitor

• Message number: 606

• Message text: Small hit ratio in ICM server cache

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message ICM606 - Small hit ratio in ICM server cache ?

  The SAP error message ICM606 indicates that there is a small hit ratio in the Internet Communication Manager (ICM) server cache. This typically means that the cache is not being utilized effectively, leading to performance issues as requests are not being served from the cache as expected.
  Cause:
  
  Low Cache Hit Ratio: The hit ratio is a measure of how many requests are being served from the cache versus how many are being processed by the backend. A low hit ratio suggests that many requests are not being found in the cache.
  Cache Configuration: The cache may not be configured optimally. This could include insufficient cache size or inappropriate cache settings.
  Dynamic Content: If the application is serving a lot of dynamic content that cannot be cached, this will naturally lead to a lower hit ratio.
  Frequent Changes: If the content being served changes frequently, it may not remain in the cache long enough to be reused.
  High Traffic: An increase in traffic can lead to cache thrashing, where the cache is constantly being filled and emptied, reducing the hit ratio.
  
  Solution:
  
  Analyze Cache Usage: Use transaction codes like ICM or SMICM to monitor cache usage and hit ratios. This can help identify patterns and issues.
  Increase Cache Size: If the cache is too small, consider increasing its size. This can be done in the ICM configuration settings.
  Optimize Cache Settings: Review and optimize the cache settings in the ICM configuration. This includes adjusting parameters like icm/HTTP/max_cache_size and icm/HTTP/enable_cache.
  Review Content: Analyze the type of content being served. If a lot of dynamic content is being served, consider whether some of it can be cached or if caching strategies can be improved.
  Implement Caching Strategies: Use caching strategies such as content expiration, cache invalidation, and pre-caching of frequently accessed content.
  Monitor and Adjust: Continuously monitor the cache hit ratio and adjust configurations as necessary based on traffic patterns and content changes.
  
  Related Information:
  
  ICM Configuration Parameters: Familiarize yourself with relevant ICM parameters in the SAP system that control caching behavior.
  Performance Monitoring: Regularly monitor performance metrics to identify trends and potential issues before they become critical.
  SAP Notes: Check SAP Notes for any known issues or recommendations related to ICM caching and performance.
  Documentation: Refer to the official SAP documentation for detailed guidance on configuring and optimizing the ICM.
  
  By addressing the underlying causes and implementing the suggested solutions, you can improve the cache hit ratio and overall performance of the ICM server.