As you might know, Microsoft has released on March 7 the RTM version of SQL Server
2012. If you are an MSDN or TechNet Subscriber, you can already download it and play
with it. As with every SQL Server release, SQL Server has also marked several features
as deprecated, which means they are removed in a future version of SQL Server.
So if you are starting a new deployment or an application based on SQL Server 2012,
you should check the following link which describes all the deprecated features and
their replacement: http://msdn.microsoft.com/en-us/library/ms143729%28v=sql.110%29.aspx.
In this blog posting I want to mention 2 deprecated features, because there are some
big changes in SQL Server 2012.
Database Mirroring:
With the release of SQL Server 2012 and AlwaysOn Availability Groups, Database Mirroring
is deprecated. Database Mirroring was introduced with SQL Server 2005 SP1 and allowed
you to mirror a database synchronous and asynchronous, and optionally you had also
an automatic failover if you used a witness instance (in combination with synchronous
mirroring).
AlwaysOn Availability Groups is an enhanced version of Database Mirroring where you
can mirror a group of databases, and where your secondary databases are readable.
AlwaysOn also provides you synchronous mirroring for HA, and asynchronous mirroring
for DR. One requirement of AlwaysOn Availability Groups is that you need to have a
Windows Server Failover Cluster (without any Shared Storage!). The Windows Server
Failover Clustering functionality is used to provide several clustering infrastructure
features like Quorum settings, Intra Node Health Checking, etc.
I already talked with some of my customers, and for a few of them this is currently
a big no-go, because they are currently using Database Mirroring where each partner
database is not in an AD domain. So they can't just migrate to AlwaysOn, because they
are not able to create a Windows Server Failover Cluster. But that is just the way
how it works now. Another drawback is that AlwaysOn Availability Groups is currently
only an Enterprise Edition feature of SQL Server. Parts of Database Mirroring are
also available in the Standard Edition. Microsoft suggests to use Log Shipping of
your SQL Server Edition doesn't support AlwaysOn Availability Groups.
SQL Server Profiler for Trace Capture
and Trace Replay
Microsoft introduced with SQL Server 2008 Extended Events. With SQL Server 2012 Microsoft
has done a lot of improvements in the area of Extended Events, for example you are
now getting a very cool UI where you can define your Event Sessions in a wizard based
way. On the long term Extended Events is the replacement for SQL Trace and SQL Server
Profiler. Therefore those features are marked as deprecated. If you are using SQL
Trace/SQL Profiler for Trace Capture and Trace Replay, SQL Server 2012 provides you
a new feature called Distributed Replay, which is a high scalable distributed replaying
technology.
So, if you have existing applications based on SQL Server, or you are starting a new
deployment on SQL Server 2012, please review the deprecated features so that you have
fewer problems in the futures.
If you are interested in SQL Server 2012, I suggest looking on my "SQL Server 2012
Deep Dive Days Workshop", which I run from May 28 – 30 in London/United Kingdom (see http://www.SQLpassion.at/events.html,
Early Bird price ends on March 31). This workshop was running this week in Vienna/Austria
with a huge success and next week I'm presenting this workshop in Munich/Germany.
Thanks for reading!
-Klaus