7.7. Miscellaneous Changes

What follows are a number of other enhancements that have been introduced in WCF4.

7.7.1. Improved Integration with WF

Microsoft has put a big focus on improving the integration between WF and WCF, and this release sees the introduction of a new project type called WF Service (a combined WCF and WF service represented entirely in XAML). Please refer to Chapter 6 for full details.

7.7.2. Default Performance-Related Settings Changed

A number of default settings for WCF services have been tweaked for better performance:

• MaxConcurrentSessions was 10, and is now 100 times processor count.

• MaxConcurrentCalls was 16, and is now 16 times processor count.

• MaxConcurrentInstances was 26, and is now the total of MaxConcurrentSettions and MaxConcurrentCalls.

7.7.3. Low Memory

A new minFreeMemoryToActivateService option has been added that defines the percentage of memory that needs to be free in order for a service to be activated (defaulted to 5%). If less than the specified memory is available, then WCF will throw an exception.

7.7.4. Other Changes

Following are some other changes that have been made:

• Event tracing for Windows is now used for tracing, offering better performance.

• There's a new DataContractResolver class that allows control over the serialization process of types (see http://msdn.microsoft.com/en-us/library/system.runtime.serialization.datacontractresolver(VS.100).aspx).

• There's a new byte stream encoder (for sending binary content over WCF—see the WCF samples again).

• Automatic decompression over HTTP for the client has been added (server not currently supported).

• Extended protection of secure channels has been added (a new Windows feature that binds one security system to another, making attacks harder).

• The addition of nondestructive queue receive (an alternative way of processing messages that makes a queue item invisible to other consumers and creates a transaction for performing work on it that if rolled back will return the item to its place on the queue—for more info, please refer to http://blogs.msdn.com/drnick/archive/2008/12/04/an-alternative-queuing-model.aspx).