QLogic 10000 Series Accelerating Microsoft SQL Server Beyond Large Server Memory - Manual (Page 3)

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White Paper Accelerating Microsoft SQL Server Beyond
Large Server Memory
QLogic FabricCache 10000 Series Adapter incorporates adapter-based,
intelligent I/O optimization engines that provide integrated storage
network connectivity, flash-based storage capacity, and the embedded
processing required to make all flash management and caching
tasks entirely transparent to the host. All “heavy lifting” is performed
transparently onboard the caching Host Bus Adapter by the embedded
multi-core processor. By delivering full hardware offload, the FabricCache
Adapter provides significant performance benefits, including conserving
server memory and processor cycles for applications and services and
maximizing the number of VMs in virtualized environments. The only
host-resident software required for operation is a standard host operating
system (OS) device driver. In fact, the device appears to the host as a
standard QLogic Fibre Channel Host Bus Adapter and uses a common Host
Bus Adapter driver and protocol stack that is the same as the one used
by the traditional QLogic Fibre Channel Adapters that already make up the
existing SAN infrastructure.
DRAM Caching QLogic FabricCache 10000 Series Adapter
Example 1
A single-server SQL database with a current size of 150GB. The size of
the database is expected to grow about 33 percent each year. The existing
server node has 32GB of DRAM with an ability to expand to 128GB using its
12 DRAM sockets.
Analysis 1
A good rule of thumb is to cache up to 30 percent of a database for the
most cost-effective and optimal performance acceleration. Caching a
higher percentage tends to provide diminishing returns. With an ability to
scale to 128GB of DRAM and a 30 percent cache ratio, a database with a
size of up to 427GB can be accelerated efficiently. This example is a good
candidate for DRAM caching accommodating three years of growth.
Example 2
A single-server SQL database with a current size of 600GB. The size of
the database is expected to grow about 40 percent each year. The existing
server node has 96GB of DRAM with an ability to expand to 768GB using its
24 DRAM sockets.
Analysis 2
While this higher-end server has plenty of DRAM expansion capabilities,
buying hundreds of gigabytes of DRAM from the server vendor is
cost-prohibitive. The QLogic FabricCache 10000 Series Adapter will be
the more cost-effective choice now and provide scalable performance
acceleration for several years of database growth.
Example 3
A single-server SQL database with a current size of 500GB. The size of
the database is expected to grow about 70 percent each year. The existing
server node has 128GB of DRAM with an ability to expand to 384GB using
its 12 DRAM sockets.
Analysis 3
Mapping out database sizes, year one will be 850GB, and year two will
be 1,445GB. Using the 30 percent cache ratio tells us that this server’s
maximum 384GB will be sufficient for year one, but by year two it will fall
short of the need. Clearly, choosing DRAM caching in this example would
be short sited. The QLogic FabricCache 10000 Series Adapter is certainly
the better choice longer term.
DRAM Caching QLogic FabricCache 10000 Series Adapter
DRAM cache is “captive” to the individual server; it is not sharable.
The QLogic FabricCache 10000 Series Adapter allows for the sharing of
cache resources between clustered servers and virtualized environments.
DRAM cache is cost-prohibitive for larger-sized databases.
The QLogic FabricCache 10000 Series Adapter is unaffected by server and
DRAM premiums and is the most cost-effective way to scale out database
size and performance.
DRAM cache best practice recommendations from Microsoft place
additional burdens on a server in the form of processor resource
consumption as well as larger and more fragmented storage capacity.
The QLogic FabricCache 10000 Series Adapter manages all caching with
full hardware offload, preserving server processing and memory resources
for applications and services as well as maximizing the number of VMs in
virtualized environments.
Servers utilizing DRAM caching for SQL will need an additional Fibre
Channel or similar Host Bus Adapter for networked storage access.
The QLogic FabricCache 10000 Series Adapter combines flash cache
with the industry’s most popular Fibre Channel Host Bus Adapter, and it is
managed as a single solution.
COMPARING DRAM CACHING LIMITATIONS TO THE QLOGIC FABRICCACHE 10000 SERIES ADAPTER
SELECTING DRAM CACHING VERSUS FABRICCACHE TO ACCELERATE MICROSOFT SQL SERVER
The QLogic 10000 Series Adapter delivers something that no other flash-
based caching solution has today: the ability to provide clustered caching
for SAN adapters and then share the adapters’ caches between servers.
Clustering FabricCache Adapters creates a logical group that cooperates to
maintain cache coherence, delivering a single point of management, high
availability, and optimal allocation of cache resources.
FabricCache Adapters communicate with each other using the Fibre
Channel infrastructure. This capability allows the cluster of adapters
to share and manage caches across multiple server nodes. After
administrators define caches for specific LUNs on the SAN, each
FabricCache Adapter can identify which adapter is the owner of each
cache. Because all FabricCache Adapters recognize the cache owner for
each specific LUN, I/Os are redirected to the cache owner. This distributed
cache model enables a single copy of cache data, which ensures coherent
cache operation, maximizes the use of flash resources, simplifies the
architecture, and increases scalability.