The Global Index Catalogs Shared Cache Extension provides a database cache in memory to store content of all global index catalogs.
The Global Index Catalogs Shared Cache Extension is shared by all the instances of the Global Index Catalogs. The Shared Cache size can be configured either with a fixed value o with a percentage of the total memory of the JVM.
The Global Index Catalogs Shared Cache Extension component inherits from the Extension
A description of each property follows.
| Basic Properties: | Advanced Properties: |
|---|---|
| ↓ db-cache-percent | ↓ db-evictor-lru-only |
| ↓ db-cache-size | ↓ db-evictor-nodes-per-scan |
| ↓ enabled | ↓ java-class |
| Description | Specifies the percentage of JVM memory to allocate to the database cache. Specifies the percentage of memory available to the JVM that should be used for caching database contents. Note that this is only used if the value of the db-cache-size property is set to "0 MB". Otherwise, the value of that property is used instead to control the cache size configuration. |
| Default Value | 40 |
| Allowed Values | An integer value. Lower value is 1. Upper value is 90 . |
| Multi-valued | No |
| Required | No |
| Admin Action Required | None |
| Advanced Property | No |
| Read-only | No |
| Description | The amount of JVM memory to allocate to the database cache. Specifies the amount of memory that should be used for caching database contents. A value of "0 MB" indicates that the db-cache-percent property should be used instead to specify the cache size. |
| Default Value | 0 MB |
| Allowed Values | A positive integer representing a size. |
| Multi-valued | No |
| Required | No |
| Admin Action Required | None |
| Advanced Property | No |
| Read-only | No |
| Description | Indicates whether the Extension is enabled. |
| Default Value | None |
| Allowed Values | true false |
| Multi-valued | No |
| Required | Yes |
| Admin Action Required | None |
| Advanced Property | No |
| Read-only | No |
| Description | Indicates whether the database should evict existing data from the cache based on an LRU policy (where the least recently used information will be evicted first). If set to "false", then the eviction keeps internal nodes of the underlying Btree in the cache over leaf nodes, even if the leaf nodes have been accessed more recently. This may be a better configuration for databases in which only a very small portion of the data is cached. |
| Default Value | true |
| Allowed Values | true false |
| Multi-valued | No |
| Required | No |
| Admin Action Required | Restart the server |
| Advanced Property | Yes |
| Read-only | No |
| Description | Specifies the number of Btree nodes that should be evicted from the cache in a single pass if it is determined that it is necessary to free existing data in order to make room for new information. Changes to this property do not take effect until the Global Index Catalogs Shared Cache Extension is restarted. It is recommended that you also change this property when you set db-evictor-lru-only to false. This setting controls the number of Btree nodes that are considered, or sampled, each time a node is evicted. A setting of 100 often produces good results, but this may vary from application to application. The larger the nodes per scan, the more accurate the algorithm. However, setting it too high is detrimental; the need to consider larger numbers of nodes for each eviction may delay the completion of a given database operation, which will impact the response time of the application thread. |
| Default Value | 10 |
| Allowed Values | An integer value. Lower value is 1. Upper value is 1000 . |
| Multi-valued | No |
| Required | No |
| Admin Action Required | Restart the server |
| Advanced Property | Yes |
| Read-only | No |
| Description | Specifies the fully-qualified name of the Java class that provides the Global Index Catalogs Shared Cache Extension implementation. |
| Default Value | com.sun.dps.server.globalindex.GlobalIndexCatalogsSharedCacheConfigManager |
| Allowed Values | A java class that implements or extends the class(es) : org.opends.server.api.Extension |
| Multi-valued | No |
| Required | Yes |
| Admin Action Required | The Global Index Catalogs Shared Cache Extension must be disabled and re-enabled for changes to this setting to take effect |
| Advanced Property | Yes |
| Read-only | No |