Resolving Inefficient Cache Usage
After you identify the cause of inefficient cache usage, you can determine the correct way to resolve the issue.
- Improperly Tuned Cache Performance Properties
- High Cache Allocation for Less Frequently Used Large Objects
- Low Cache Allocation for More Frequently Used Small Objects
For more information about changing the cache values in the Performance Tuning Utility, refer to the topic Viewing or Editing Performance Configuration Settings.
For more information about changing the cache values manually using the noapp.properties file, refer to the topic Manual Performance Tuning.
Improperly Tuned Cache Performance Properties
If you review the Cache Usage Report and notice that the number of requests are increasing and the number of hits are decreasing for the same cache, increase the cache values using the Performance Tuning Utility, or manually increase the values in the install_dir/properties/noapp.properties file.
- Increasing the size too much does not make the system any more effective than reading from the disk. Depending on your system and your configuration, you may have to adjust the cache settings to attain peak performance without losing the benefit of cache over disk.
- Increasing the cache sizes for items that are not used frequently may degrade performance because more resources are allocated to the caches, but are not being used.
High Cache Allocation for Less Frequently Used Large Objects
If you review the Cache Usage Report and notice that the number of requests to the cache are low, you can reduce the size of the cache values using the Performance Tuning Utility, or manually decrease the values in the install_dir/properties/noapp.properties file. The low request number indicates that the objects in the cache are not used frequently with your business processes. Review the value for the cache property and reduce the cache size if the cache size is large.
Decreasing the cache size too much may cause a reduced number of hits to the caches, which results in a call to the database for data, and increases the processing time. Depending on your system and your configuration, you may have to adjust the cache settings to attain peak performance without losing the benefit of cache over disk.
Low Cache Allocation for More Frequently Used Small Objects
If you review the Cache Usage Report and notice that the number of requests to the cache are high and the number of hits to the cache are low, you can increase the size of the cache values using the Performance Tuning Utility, or manually increase the values in the install_dir/properties/noapp.properties file. The high request number indicates that the objects in the cache are being used frequently with your business processes. Review the values for the cache properties and increase the cache size if the cache size is small. This is especially important for the smaller objects that are used frequently and are static in value. Cache retrieval is faster than disk or database retrieval.
Increasing the cache sizes too much may cause a reduced number of hits to the caches for larger objects. This results in a call to the database for data, and increases the processing time. Depending on your system and your configuration, you may have to adjust the cache settings to attain peak performance without losing the benefit of cache over disk.