Great application using Entity infrastructure and WCF

We are developing a large ASP.NET application. The application uses the following:

• The structure of the object as a level of data access.
• Because WCF is the link layer that ChannelFactory uses to create channels (each call has a new channel), WCF services are hosted on Windows services and use WSHttpBinding.

• SQL Server 2008 R2

• Sometimes we use TransactionScope at the business level to create transactions.

• The database contains a large amount of data that is transmitted through WCF.
• All of our Entity Framework ObjectContexts are wrapped inwards using statemnt to ensure their location.
• Each WCF channel is located after its use.
• We have long transactions that run in the background, which contain a lot and frequent access to the database also through WCF.

Basically, we have two critical problems:

• We have some kind of memory leak. WCF service host memory continues to grow and grow, especially with big data.
• SQL Server memory is also expanding and expanding.

These problems make the application very slow and sometimes not responding, which forces us to restart the wcf and sql services.

The application is hosted on a Windows Server 2008 environment with 4 GB of RAM.