1.2. Per-Invocation Flags

The putForExternalRead() method in Red Hat JBoss Data Grid's Cache API uses flags internally. This method can load a JBoss Data Grid cache with data loaded from an external resource. To improve the efficiency of this call, JBoss Data Grid calls a normal put operation passing the following flags:

Combining the flags above significantly increases the efficiency of the operation. The basis for this efficiency is that putForExternalRead calls of this type are used because the client can retrieve the required data from a persistent store if the data cannot be found in memory. If the client encounters a cache miss, it retries the operation.

For a detailed list of all flags available for JBoss Data Grid are available in the JBoss Data Grid API Documentation here: https://access.redhat.com/documentation/en-US/Red_Hat_JBoss_Data_Grid/6.6/html/API_Documentation/files/api/org/infinispan/context/Flag.html

To use per-invocation flags in Red Hat JBoss Data Grid, add the required flags to the advanced cache via the withFlags() method call.

Cache cache = ...
	cache.getAdvancedCache()
	   .withFlags(Flag.SKIP_CACHE_STORE, Flag.CACHE_MODE_LOCAL)
	   .put("local", "only");

In a use case for Red Hat JBoss Data Grid, where a write operation, such as put(), must not return the previous value, the IGNORE_RETURN_VALUES flag is used. This flag prevents a remote lookup (to get the previous value) in a distributed environment, which in turn prevents the retrieval of the undesired, potential, previous value. Additionally, if the cache is configured with a cache loader, this flag prevents the previous value from being loaded from its cache store.

Cache cache = ...
	cache.getAdvancedCache()
	   .withFlags(Flag.IGNORE_RETURN_VALUES)
	   .put("local", "only")