Cache Management System 

Use

The AS Java implements the concept of a centralized cache management infrastructure that consolidates caches that are used by various applications within the SAP system landscape. This infrastructure is provided by the Cache Management Library (CML).

Features

The system provides central configuration of all caches. It allows the user to change the behavior of the cache (scope, thresholds, eviction).

System wide cache analysis and optimization, as well as central monitoring of all caches (hit rate, miss rate, request count, update count, remove count, eviction count, utilization and so on) are available for administration purposes.

The Cache Management System also provides the following features:

●      Sharing of caches between all nodes of an instance.

●      Cluster-wide invalidation of cached objects.

●      Tools to analyze the cache size and behavior of each region.

Activities

Enabling Cache Benchmarking and Monitoring

The cache.benchmark.enabled property allows you to check basic performance parameters on a particular system.

The cache.monitoring.enable property allows you to monitor the centralized cache management (in SAP Management Console).

To modify the properties, use the following procedure:

Start ...

       1.      Start the Config Tool.

       2.      Choose cluster-data → template → instance - <n> → managers → CacheManager.

       3.      From the list of properties, select cache.benchmark.enabled.

       4.      In the Custom value field, set the required Boolean value.

       5.      To apply the new value, choose Set.

       6.      To save the changes, choose  Apply changes.

       7.      For the changes to take effect, restart the cluster.

You can use this procedure analogically to configure the cache.monitoring.enable property.

Configuring Database Cache Connections

The cml.dbWorkerThreadsNumber property limits the number of database threads used by the cache. If this number is high, it can lead to a system performance degradation. If you need to modify this property, we recommend to set a maximum value between 10 and 15.

To modify the property, use the following procedure:

1. Start the Config Tool.
2. Choose cluster-data → template → instance - <n> → services → tc~je~cachemgmt~srv.
3. From the list of properties, select cml.dbWorkerThreadsNumber.
4. In the Custom value field, set the required value.
5. To apply the new value, choose Set.
6. To save the changes, choose  Apply changes..
7. For the changes to take effect, restart the cluster.