How To Fix SDBALM186 - Low hit rate for OMS history data in the data cache (&1&3 < &2&3)

SAP Error Message - Details

• Message type: E = Error

• Message class: SDBALM - SAP DB and liveCache Alert Monitoring

• Message number: 186

• Message text: Low hit rate for OMS history data in the data cache (&1&3 < &2&3)

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message SDBALM186 - Low hit rate for OMS history data in the data cache (&1&3 < &2&3) ?

  The SAP error message SDBALM186 indicates that there is a low hit rate for the Online Monitoring System (OMS) history data in the data cache. This can lead to performance issues, as the system is not efficiently retrieving data from the cache, which can result in increased database access and slower response times.
  Cause:
  The low hit rate for OMS history data can be caused by several factors, including:
  
  Insufficient Cache Size: The cache may not be large enough to hold the frequently accessed data, leading to a higher number of cache misses.
  Data Volatility: If the data in the cache changes frequently, it may not be reused effectively, resulting in a low hit rate.
  Configuration Issues: Incorrect configuration settings for the cache or the OMS can lead to suboptimal performance.
  High Data Load: A sudden increase in data volume or user activity can overwhelm the cache, leading to a low hit rate.
  Inefficient Queries: Queries that do not leverage the cache effectively can also contribute to low hit rates.
  
  Solution:
  To address the low hit rate for OMS history data, consider the following solutions:
  
  
  Increase Cache Size: Adjust the cache size settings in the SAP system to accommodate more data. This can help improve the hit rate by allowing more frequently accessed data to remain in the cache.
  
  
  Optimize Configuration: Review and optimize the configuration settings for the OMS and the data cache. Ensure that they are set according to best practices and the specific needs of your environment.
  
  
  Monitor Data Access Patterns: Use monitoring tools to analyze data access patterns. This can help identify which data is frequently accessed and may need to be prioritized in the cache.
  
  
  Tune Queries: Review and optimize the queries that access the OMS history data. Ensure that they are designed to take advantage of the cache effectively.
  
  
  Regular Maintenance: Perform regular maintenance on the database and cache to ensure optimal performance. This includes clearing old or unused data from the cache.
  
  
  Consult SAP Notes: Check for any relevant SAP Notes or updates that may address known issues related to the OMS and data caching.
  
  
  Related Information:
  
  Transaction Codes: You can use transaction codes like ST02 (Tune Summary) to monitor buffer and cache performance.
  SAP Documentation: Refer to the official SAP documentation for detailed guidelines on configuring and optimizing the OMS and data cache.
  Performance Monitoring Tools: Utilize SAP's performance monitoring tools to gain insights into system performance and identify bottlenecks.
  
  By addressing the underlying causes and implementing the suggested solutions, you can improve the hit rate for OMS history data and enhance overall system performance.