Region Data Policies

This topic lists and describes the region data policies in VMware Tanzu GemFire.

The region data policy is a region attribute, data-policy. For information about region attributes, see Managing Region Attributes.

A region’s data-policy specifies how the local cache handles data for a region. This setting controls behavior such as local data storage and region initialization.

Note: You can configure the most common options using the region shortcuts, RegionShortcut and ClientRegionShortcut. The default data-policy of normal specifies local cache storage. The "empty" policy specifies no local storage. In the region shortcuts, "empty" corresponds to the settings with the string PROXY. You can use an empty region for event delivery to and from the local cache without the memory overhead of data storage.

You can specify a region’s data-policy as one of the following:

Data Policy	Description
empty	No data storage in the local cache. The region always appears empty. Use this for event delivery to and from the local cache without the memory overhead of data storage, zero-footprint producers that only distribute data to others and zero-footprint consumers that only see events. To receive events with this, set the region's subscription-attributes interest-policy to all.
normal	Data that is used locally (accessed with get, stored with put, etc.) is stored in the local cache. This policy allows the contents in the cache to differ from other caches.
partition	Data is partitioned across local and remote caches using the automatic data distribution behavior of partitioned regions. Additional configuration is done in the partition-attributes.
persistent-partition	Behaves the same as partition and also persists data to disk.
persistent-replicate	Behaves the same as replicate and also persists data to disk.
preloaded	Initializes like a replicated region. After initialization, behaves like a normal region.
replicate	The region is initialized with the data from other caches. After initialization, all events for the distributed region are automatically copied into the local region, maintaining a replica of the entire distributed region in the local cache. Operations that would cause the contents to differ with other caches are not allowed. This is compatible with local scope, behaving the same as for normal.