The Sizing Attributes
Tuning BigMemory Max often involves sizing the data storage tiers appropriately. You can size the different data tiers in a number of ways using simple sizing attributes. These sizing attributes affect memory and disk resources.
The following table summarizes the sizing attributes you can use.
| Tier | Attribute | Description |
|---|---|---|
| Memory Store (Heap) |
|
The maximum number of
entries or bytes a data set can use in local heap memory, or when set at the
CacheManager level (maxBytesLocalHeap only), as a pool available to all data
sets under that CacheManager. This setting is required for every cache or at
the CacheManager level.
Pooling is available at the CacheManager
level using
|
| Off-heap Store |
|
The maximum number of
bytes a data set can use in off-heap memory, or when set at the CacheManager
level, as a pool available to all data sets under that CacheManager.
Pooling is available at the CacheManager level. |
| Disk Store |
|
The maximum number of
entries or bytes a data set can use on the local disk, or when set at the
CacheManager level (maxBytesLocalDisk only), as a pool available to all data
sets under that CacheManager. Note that these settings apply to temporary disk
usage (localTempSwap); these
settings do not apply to disk persistence.
Pooling is available at the CacheManager
level using
|
The following table summarizes sizing attributes for distributed BigMemory Max (using a Terracotta Server or a Server Array).
| Tier | Attribute | Description |
|---|---|---|
| Heap |
|
The maximum number of
cache entries or bytes a cache can use in local heap memory, or, when set at
the CacheManager level (maxBytesLocalHeap only), a local pool
available to all caches under that CacheManager. This setting is required for
every cache or at the CacheManager level.
Pooling is available at the CacheManager
level using
|
| Off-heap |
|
The maximum number of
bytes a cache can use in off-heap memory, or, when set at the CacheManager
level, as a pool available to all caches under that CacheManager. This setting
requires BigMemory.
Pooling is available at the CacheManager level. |
| Local disk | N/A | Distributed caches
cannot use the local disk.
Pooling at the CacheManager level is not available. |
| Terracotta Server Array |
|
The number of cache
elements that the Terracotta Server Array will store for a distributed cache.
This value must be greater than or equal to the number of entries in all of the
clients of the server array. Set on individual distributed caches only, this
setting is unlimited by default.
Pooling at the CacheManager level is not available. |
Attributes that set a number of entries or elements take an integer. Attributes that set a memory size (bytes) use the Java -Xmx syntax (for example: "500k", "200m", "2g") or percentage (for example: "20%"). Percentages, however, can be used only in the case where a CacheManager-level pool has been configured.
