Exchange Server 2010: What's New and What's Changed?
Author: Allan Jacobs
Abstract
Microsoft's Exchange Server 2010 makes substantial strides to
provide a robust and reliable approach to the messaging
environment. Users will see gains in the speed at which messages
flow through the system, as well as substantial improvement in
messaging redundancy. Administrators will benefit from improved
remote management capability and a model that provides truly
granular control. The end-user will see a more robust version of
OWA, improved UM functionality, and reminders that will prevent
improperly relayed or unproductive email from being sent.
Introduction
E-mail has become the lifeblood of enterprise communication in
the 21st century, and Microsoft's Exchange Server has positioned
itself as virtually the only game in town. Sure, there are still
organizations that use Lotus Notes or Novell GroupWise, but they
are frequently migrating to Exchange. Having cornered the messaging
market, the guys in Redmond, Washington are not sitting on their
hands; they have provided us with a new version of Exchange that
makes significant improvements over the previous version for the
organization, its administrators, and the end-users.
The enterprise using Exchange 2003 will have no choice but to
migrate to the 2010 version. Exchange 2003 will not be supported
much longer, and the drawbacks of that product have become apparent
in the days of large e-mail and bloated mailboxes. Those
organizations that have already moved to Exchange 2007 will wish to
consider which of the new features of Exchange 2010 will have the
most impact on their messaging environment and will likely conclude
that it's worth the effort to move to the new product.
In this white paper, we will look at some of the key changes
that will be revealed with the new version of Exchange and how
these changes will impact the messaging environment.
Changes for the Organization
Since the unification of the Exchange Directory with Active
Directory in Exchange 2000, considerable changes have been
implemented in the architecture of the product in an effort to keep
up with colossal expansion of the use of e-mail and the size of the
mailboxes. The improvements of Exchange that will have the most
impact on the enterprise are designed to ensure that the messaging
servers are reliable and robust.
The Database Availability Group
(DAG)
Perhaps the single most significant change in the Exchange
Server design is in the area of high availability. With Exchange
Server 2007, Microsoft introduced continuous replication as an
approach to providing redundancy of the user's mailboxes. The
continuous replication technologies came in three flavors: Local
Continuous Replication (LCR), Cluster Continuous Replication (CCR),
and Standby Continuous Replication (SCR). These technologies
permitted organizations to avoid the cost and complexity of
deploying the classic Single Copy Cluster (SCC), whose approach to
failover clusters essentially duplicated the high availability
approach of the previous versions of Exchange.
Exchange 2010 essentially eliminates LCR and SCC, and rolls the
CCR and SCR into a single unified process known as the Database
Availability Group (DAG). The DAG can contain as many as 16
replicas of a mailbox database to provide for truly distributed
database access. The structure of the DAG provides the enterprise
with an availability and storage model that can eliminate the need
for costly Storage Area Networks (SANs), without sacrificing their
reliability.
Storage Issues
While speaking of our Mailbox Servers, we should note that the
new version of Exchange has eliminated the use of Storage Groups,
and the Mailbox Databases are no longer directly connected to the
Server Object. This new configuration greatly supports the DAG
architecture and allows for the management of Mailbox Databases at
the Organization Level, instead of the Server Level as in Exchange
2007. This new design makes migration and recovery a much easier
process.
In the Exchange community, a subject of frequent discussion has
been the continued use of the Extensible Storage Engine (ESE)
database as the backbone of the infrastructure. There were some who
were hoping that Exchange 2010 would include the adoption of
Microsoft's SQL Server as the mailbox database. Those individuals
might be disappointed to learn that 2010 does not provide us with a
SQL database, yet, through re-engineering, Exchange 2010 has
achieved a substantial improvement in the speed of Input/Output
Operations. The Exchange Team has touted the improvement to
approach 70%, and that speed, combined with the large bump seen
when moving from Exchange Server 2003 to Exchange 2007, should
satisfy the critics concerned about the continued use of the ESE
database. An added plus in retaining the database structure is the
relative ease of migration from previous versions to Exchange 2010,
which surely would have suffered a major blow by moving to a SQL
database.
Structurally, Exchange 2010 now has all data flow through the
Client Access Server (CAS), regardless of whether it is coming in
from a web or MAPI client. This new construct is intended to
support the DAG design and the independence of the Mailbox Database
from a specific Mailbox Server.
Related Courses
Microsoft Exchange Server 2007