Database Reference
In-Depth Information
Chapter 8. Architecting for Performance: Network
We have now reached the final IT food group—the network. Although SQL Server is
generally not very network intensive, the network is very important as the means of
access for all clients and applications, as well as the means of access to storage in a
SAN environment. When you are using advanced configurations such as SQL AlwaysOn
Failover Cluster Instances and AlwaysOn Availability Groups, the network becomes
even more important because it is the means of data replication and cluster failure
detection. A fast, reliable, low-latency network will improve the speed of response to
your applications and clients. In a virtualized environment, the network is also heavily
used to provide greater flexibility and manageability through the use of VMware
vMotion and VMware DRS. Providing the appropriate quality of service for different
network traffic types—such as client traffic, cluster traffic, replication traffic,
management, and vMotion traffic—is important to ensure you can meet application
service levels.
Tip
For SQL Server DBAs, operating virtualized databases is simpler than physical
or native database servers from a network perspective. There is no need to
configure network teaming or VLAN drivers inside Windows. There is also no
need to configure storage multipathing drivers—the only exception being where
you are using in-guest iSCSI connectivity to storage. Network teaming and
storage multipathing are handled transparently, reliably, and simply through
VMware vSphere. No longer will a misconfigured or misbehaving teaming driver
or Windows multipathing problems cause an issue for your database.
This chapter covers how to get the required network performance from your SQL
Server VMs—from using the right network adapter type, cluster network settings, and
the benefits of jumbo frames, to designing and configuring your hypervisor and your
physical network for performance, quality of service, and network security.
SQL Server and Guest OS Network Design
This section focuses on getting the best network performance out of SQL Server and
your Windows virtual machines when running in a VMware vSphere environment. A
number of options and best practices that can be used to improve network performance
and reliability, which we cover in this section. It is recommended that you consider the
options during your design process and come up with a standardized configuration that
can be applied to your templates. This will reduce operational complexity. Remember
