Use this page to configure and manage the dynamic cache service settings.
To view this administrative console page, click Servers > Application servers > server_name > Container services > Dynamic cache service.
Specifies whether the dynamic cache is enabled when the server starts.
Specifies a positive integer as the value for the maximum number of entries that the cache holds.
Enter a cache size value in this field that is between the range of 100 through 200,000.
Specifies the default priority for cache entries, determining how long an entry stays in a full cache.
| Default | 1 |
| Range | 1 to 255 |
Specifies whether disk offload is enabled.
By default, the dynamic cache maintains the number of entries that are configured in memory. If new entries are created while the cache is full, the priorities that are configured for each cache entry, and a least recently used algorithm, are used to remove entries from the cache. In addition to having a cache entry removed from memory when the cache is full, you can enable disk offload to have a cache entry copied to the file system (the location is configurable). Later, if that cache entry is needed, it is moved back to memory from the file system. Before you enable disk offload, consider the following:
Location on the disk to save cache entries when disk offload is enabled.
If disk offload location is not specified, the default location, ${WAS_TEMP_DIR}/node/server name/_dynacache/cache JNDI name is used. If disk offload location is specified, the node, server name, and cache instance name are appended. For example, ${USER_INSTALL_ROOT}/diskoffload generates the location as ${USER_INSTALL_ROOT}/diskoffload/node/server name/cache JNDI name. This value is ignored if disk offload is not enabled. The default value of the ${WAS_TEMP_DIR} property is ${USER_INSTALL_ROOT}/temp. If you change the value of the ${WAS_TEMP_DIR} property after starting WebSphere Application Server, but do not move the disk cache contents to the new location:
When you are specifying a directory, consider the following:
Specifies if in-memory cached objects are saved to disk when the server is stopped. This value is ignored if Enable disk offload is not selected.
| Default | false |
Specifies a value for the maximum disk cache size in GB. When you select this option, you can specify a positive integer value. Leaving this option blank indicates an unlimited size. This setting applies only if enable disk offload is specified for the cache.
| Value | 3 and above. |
Specifies a value for the maximum disk cache size in number of entries. When you select this option, you can specify a positive integer value. Leaving this option blank indicates an unlimited size. This setting applies only if enable disk offload is specified for the cache.
| Value | 0 to MAXINT. A value of 0 indicates unlimited size. |
Specifies a value for the maximum size of an individual cache entry in MB. Any cache entry larger than this, when evicted from memory, will not be offloaded to disk. When you select this option, you can specify a positive integer value. Leaving this option blank indicates an unlimited size. This setting applies only if enable disk offload is specified for the cache.
| Value | 0 to MAXINT. A value of 0 indicates unlimited size. |
Level of performance that is required by the disk cache. This setting applies only if enableDiskOffload is specified for the cache. Performance levels determine how memory resources should be used on background activity such as cache cleanup, expiration, garbage collection, and so on. This setting applies only if enable disk offload is specified for the cache.
| High performance and high memory usage | Indicates that all metadata will be kept in memory. |
| Balanced performance and balanced memory usage | Indicates some metadata will be kept in memory. This is the default performance setting and will provide an optimal balance of performance and memory usage for most users. |
| Low performance and low memory usage | Indicates that limited metadata will be kept in memory. |
| Custom performance | Indicates that the administrator will explicitly configure the memory settings that will be used to support the above background activity. The administrator sets these values using the DiskCacheCustomPerformanceSettings object. |
Specifies a value for the disk cache cleanup frequency, in minutes. If this value is set to 0, the cleanup runs only at midnight. This setting applies only when the Disk Offload Performance Level is low, balanced, or custom. The high performance level does not require disk cleanup, and this value is ignored.
| Value | 0 to 1440 |
Specifies a value for the maximum number of cache identifiers that are stored for an individual dependency ID or template in the disk cache metadata in memory. If this limit is exceeded the information is offloaded to the disk. This setting applies only when the disk offload performance level is CUSTOM.
| Value | 100 to MAXINT |
Specifies a value for the maximum number of dependency identifier buckets in the disk cache metadata in memory. If this limit is exceeded the information is offloaded to the disk. This setting applies only when the disk cache performance level is custom.
| Value | 100 to MAXINT |
Specifies a value for the maximum number of template buckets that are in the disk cache metadata in memory. If this limit is exceeded the information is offloaded to the disk. This setting applies only when the disk cache performance level is custom.
| Value | 10 to MAXINT |
Specifies the eviction algorithm that the disk cache will use to evict entries once the high threshold is reached. This setting applies only if enable disk offload is specified for the cache. This setting does not apply when the disk cache eviction policy is set to none.
| None | No eviction policy, so the disk cache can grow until it reaches its limit at which time the dynamic cache service stops writing to disk |
| Random | When the disk size reaches a high threshold limit, the disk cache garbage collector wakes up and randomly picks entries on the disk and evicts them until the size reaches a low threshold limit. |
| Size | When the disk size reaches a high threshold limit, the disk cache garbge collector wakes up and picks the largest entries on the disk and evicts them until the disk size reaches a low threshold limit. |
Specifies when the eviction policy runs. The threshold is expressed in terms of the percentage of the disk cache size in GB or entries. The lower value is used when limit disk cache size in GB and limit disk cache size in entries are specified. This setting does not apply when the disk cache eviction policy is set to none.
| Values | 1 to 100 |
Specifies when the eviction policy will end. The threshold is expressed in terms of the percentage of the disk cache size in GB or entries. The lower value is used limit disk cache size in GB and limit disk cache size in entries are specified. This setting does not apply when the disk cache eviction policy is set to none.
| Values | 1 to 100 |
Use cache replication to have cache entries copied to multiple application servers that are configured in the same replication domain.
Specifies a replication domain from which your data is replicated.
Choose from any replication domains that have been defined. If there are no replication domains listed, create one during cluster creation or manually in the administrative console by clicking Environment > Internal replication domains > New. The replication domain you choose to use with the dynamic cache service must be using a Full group replica. Do not share replication domains between replication consumers. Dynamic cache should use a different replication domain from session manager or stateful session beans.
Specifies the global sharing policy for this application server. The following settings are available:
The default is Not Shared.
Timeime, in seconds, to wait before pushing new or modified cache entries to other servers.
A value of 0 (zero) sends the cache entries immediately. Setting this property to a value greater than 0 (zero) results in a "batch" push of all cache entries that are created or modified during the time period. The default is 1 (one).