1.2. Per-Invocation Flags
Per-invocation flags can be used with data grids in Red Hat JBoss Data Grid to specify behavior for each cache call. Per-invocation flags facilitate the implementation of potentially time saving optimizations.
1.2.1. Per-Invocation Flag Functions
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:
- The
ZERO_LOCK_ACQUISITION_TIMEOUTflag: JBoss Data Grid uses an almost zero lock acquisition time when loading data from an external source into a cache. - The
FAIL_SILENTLYflag: If the locks cannot be acquired, JBoss Data Grid fails silently without throwing any lock acquisition exceptions. - The
FORCE_ASYNCHRONOUSflag: If clustered, the cache replicates asynchronously, irrespective of the cache mode set. As a result, a response from other nodes is not required.
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.
