The 1.1 release of the .NET Client Library contains a series of new API methods designed to provide developers with more details about the success or failure of an operation performed by the client.

The existing API methods remain in place and as such, these changes are not breaking. Each of the new methods has the standard API method name prefixed by Execute. For example Store becomes ExecuteStore.

var storeResult = client.ExecuteStore(StoreMode.Set, "foo", "bar");

 if (! result.Success) {
 Console.WriteLine("Operation failed: {0}", result.Message);
 }

Each of the new Execute methods returns an instance of an IOperationResult, with is extended by various operation specific interfaces - IGetOperationResult, IStoreOperationResult, IConcatOperationResult, IMutateOperationResult and IRemoveOperationResult.

IOperationResult defines common properties available to all results returned by Execute methods.

IOperationResult opertionResult = client.Store(StoreMode.Set, "foo", "bar");

 //Was the operation successful (i.e., no errors or exceptions)?
 Console.WriteLine("Success: " + operationResult.Success);

 //Print out possible error, warning or informational message
 Console.WriteLine("Message: " + operationResult.Message);

 //Print out a caught exception
 Console.WriteLine("Exception: " + operationResult.Exception.Message);

 //Print out status code (nullable)
 Console.WriteLine("StatusCode: " + operationResult.StatusCode);

 //Print out InnerResult, which is populated on handled failures (i.e., IO exceptions)
 Console.WriteLine("InnerResult: " + operationResult.InnerResult.Message);

Store, Get, Mutate and Concat operation results all return Cas values.

var getResult = client.ExecuteGet("foo");

 //Print out the Cas value
 Console.WriteLine("Cas value for 'foo':" + getResult.Cas);

Get operation results also expose HasValue and Value properties.

var getResult = client.ExecuteGet("foo");

 //Print out whether getResult contains a value (shortcut for value null check)
 Console.WriteLine("getResult HasValue: " + getResult.HasValue);

 //Print out the item value
 Console.WriteLine("Value for 'foo':" + getResult.Value);

Most failures are likely to fall into one of two categories. The first are conditions that the server won't allow. For example, a Cas operation with an expired CAS value would be a failure. Attempting to add a key when that key already exists would also be failure. The second category of likely failures would occur when the client can't connect to a node.

Both categories of failures are likely to be reported by lower-level components within the client library. These components handle these errors gracefully and then log the problem. Before 1.1, these failure conditions were swallowed and did not propagate up to the caller. As a consequence, it is a good idea to check the InnerResult for a failed operation result.