In this series of posts I will go through Exchange 2010 SP1 Hosting details starting from Overview, Deployment, Migration, Multi-Tenant,...etc.
Microsoft Exchange Server 2010 SP1 supports hosting deployments and provides Hosting Partners the core feature-set of Exchange Server in a manner that can be deployed to multiple customers in a single installation, and provides ease of management and flexibility of provided features to end-users.
The hosting solution available for Exchange 2010 SP1 includes most of the features and functionality available in Exchange 2010 SP1 Enterprise deployments, but also includes features and functionality that will allow hosters to create and manage tenant organizations; however Exchange 2010 SP1 doesn't support the following features in Hosting mode:
The Exchange Server 2010 SP1 Hosting supports the following three separate server roles required to perform the tasks of a carrier-class messaging system
Flexible System Scaling Approach
Although it is technically possible to combine multiple Exchange 2010 server roles onto a single physical or virtual server, one of the goals of this Exchange 2010 SP1 Hosting architecture is to recommend against combining server roles. By implementing a single-role server deployment methodology, service providers can designate server hardware more accurately according to specific tasks, and increase the capacity of the messaging environment selectively, according to specific demands and changing trends. For example, as demand for mobile messaging services continues to grow, service providers can increase the number of Client Access servers without affecting other areas in the messaging environment
Role-Specific Load Balancing and Fault Tolerance and High Availability
Different server roles support different techniques and architectures for load balancing and fault tolerance. For example, if multiple Hub Transport servers exist in the same Active Directory® site, Exchange Server 2010 balances the message traffic automatically between these servers, whereas Mailbox servers are not load-balanced in the same way. Redundant copies of mailbox databases can be replicated across multiple servers arranged into Database Availability Groups (DAGs) to achieve fault tolerance.
Table below shows the load balancing technology per server role that service providers should use in a production environment to implement high availability and fault tolerance.
Load Balancing Technology
Exchange Database Availability Groups (DAGs)
Automatic load balancing through Mail Submission Service
Hardware load balancing for incoming mail connectivity
Hardware load balancing
Exchange 2010 Data Base Availability Group (DAG)
The new concept of the Database Availability Group (DAG) is exciting Exchange 2010 technology to bring low cost high availability without costly hardware SAN infrastructure.
Microsoft Exchange Server 2010 clients will connect to Client Access Servers, which will proxy the requests to the client. No more LCR, SCR, or CCR…DAG (or Super CCR) uses low cost DAS storage to leverage a “Raid 5” striping of databases to multiple servers. Client Access Servers (set in load balanced server farms), will provide primary HTTP and a new “distributed RPC endpoint” for Office 2010, Office 2007 emulation of a “standard exchange mailbox server” without needing to upgrade the clients.
Since clients connect to the CAS servers to proxy requests to the mailbox servers, failover from mailbox server to another in the DAG happen in less than 30 seconds in a failover or move command.
Some other notable highlights in Exchange 2010 database and HA architecture:
In the next post I will go through Exchange 2010 SP1 Hosting description.