Chapter 4. The Asynchronous API

In addition to synchronous API methods, Red Hat JBoss Data Grid also offers an asynchronous API that provides the same functionality in a non-blocking fashion.

The asynchronous method naming convention is similar to their synchronous counterparts, with Async appended to each method name. Asynchronous methods return a Future that contains the result of the operation.

For example, in a cache parameterized as Cache<String, String>, Cache.put(String key, String value) returns a String, while Cache.putAsync(String key, String value) returns a FutureString.

The asynchronous API does not block, which provides multiple benefits, such as:

These benefits allow you to better harness the parallelism in your system, for example:

Set<Future<?>> futures = new HashSet<Future<?>>();
futures.add(cache.putAsync("key1", "value1"));
futures.add(cache.putAsync("key2", "value2"));
futures.add(cache.putAsync("key3", "value3"));

In the example, The following lines do not block the thread as they execute:

The remote calls from the three put operations are executed in parallel. This is particularly useful when executed in distributed mode.

For a typical write operation in Red Hat JBoss Data Grid, the following processes fall on the critical path, ordered from most resource-intensive to the least:

In Red Hat JBoss Data Grid, using asynchronous methods removes network calls and marshalling from the critical path.

When the asynchronous API is used in Red Hat JBoss Data Grid, the client code requires the asynchronous operation to return either the Future or the CompletableFuture in order to query the previous value.

Call the following operation to obtain the result of an asynchronous operation. This operation blocks threads when called.

Future.get()