This is an option which allows storage of index related metadata to be pushed to the cluster using asynchronous operations.
Very effective on throughput but I suspect it's only safe to enable for async backends.
It might be ok for synchronous backends too but that still needs extensive testing; for now I would only expose the configuration property and enable it by default for async backends.

See also:

• https://issues.jboss.org/browse/ISPN-4611
• https://github.com/infinispan/infinispan/pull/2934/files