How To Fix SMMSS_ALERTS023 - Data cache hit ratio of &1% could be improved

SAP Error Message - Details

• Message type: E = Error

• Message class: SMMSS_ALERTS - Message class for MSSQL rz20 messages

• Message number: 023

• Message text: Data cache hit ratio of &1% could be improved

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message SMMSS_ALERTS023 - Data cache hit ratio of &1% could be improved ?

  The SAP error message SMMSS_ALERTS023 indicates that the data cache hit ratio is low, specifically at a percentage of &1%. This message is part of the SAP system monitoring alerts and is related to performance issues in the system.
  Cause:
  The data cache hit ratio measures the effectiveness of the cache in storing frequently accessed data. A low hit ratio suggests that the system is frequently accessing the database instead of retrieving data from the cache, which can lead to performance degradation. The causes of a low data cache hit ratio can include:
  
  Insufficient Cache Size: The cache may not be large enough to hold the frequently accessed data.
  High Data Volume: An increase in the volume of data being processed can lead to cache misses.
  Inefficient Data Access Patterns: If the application is not designed to take advantage of caching, it may lead to unnecessary database calls.
  Configuration Issues: Incorrect configuration settings for the cache can lead to suboptimal performance.
  Frequent Changes in Data: If the data changes frequently, the cache may not be able to retain useful data for long.
  
  Solution:
  To improve the data cache hit ratio, consider the following solutions:
  
  
  Increase Cache Size: Adjust the cache size settings in the SAP system to allow for more data to be stored in memory.
  
  This can be done in the SAP profile parameters (e.g., icm/HTTP/enable_cache).
  
  
  
  Optimize Data Access Patterns: Review and optimize the application code to ensure that it makes efficient use of the cache.
  
  Analyze the queries and data access patterns to minimize unnecessary database calls.
  
  
  
  Monitor and Analyze Performance: Use SAP transaction codes like ST02 (Tune Summary) and ST03 (Workload Analysis) to monitor cache performance and identify bottlenecks.
  
  
  Adjust Configuration Settings: Review and adjust the configuration settings related to caching in the SAP system.
  
  This may include parameters related to the buffer and cache settings.
  
  
  
  Regular Maintenance: Perform regular maintenance tasks such as database optimization and cleanup to ensure that the system runs efficiently.
  
  
  Consult SAP Notes: Check for any relevant SAP Notes that may provide specific recommendations or patches related to caching issues.
  
  
  Related Information:
  
  
  Transaction Codes: 
  
  ST02: Tune Summary - to monitor buffer and cache performance.
  ST03: Workload Analysis - to analyze system performance and workload.
  SM12: To check for locks that may be affecting performance.
  
  
  
  SAP Documentation: Refer to the official SAP documentation for detailed information on caching mechanisms and performance tuning.
  
  
  SAP Community: Engage with the SAP Community forums for insights and shared experiences from other users who may have faced similar issues.
  
  
  By addressing the underlying causes and implementing the suggested solutions, you can improve the data cache hit ratio and enhance the overall performance of your SAP system.