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ServerNet II SAN Technology Improves the Response of Clusters
ERP and database applications usually operate efficiently if powerful CPUs and large memory
resources are available to them. Distributed ERP applications accommodate more users (scale) by
adding applications servers (Figure 1), which increases the need for SQL services from the
database. Overall system performance depends upon the ability to keep the database busy.
However, extreme software overhead generated by traditional network technologies forces the
database to let the operating system functions and heavy communication protocols use a substantial
portion of the CPU resources. With ServerNet II, database CPU utilization increases more than
three times that of gigabit Ethernet and TCP/IP with the messaging loads just described. Published
benchmark results demonstrate the value of ServerNet II SAN technology by increasing the number
of SAP SD users supported by the system by more than 30 percent.
Parallel relational database architectures rely on clustering multiple nodes to support very large
databases and increase database availability. Queries, updates, and utility functions are distributed
across multiple servers within a database cluster to maximize parallelism and to reduce the impact
of a failure. Parallel relational databases rely on message systems to distribute processes, data, and
database control information to database instances within the cluster. Parallel databases demand
more than CPU efficiencies from the messaging system. Low message latency allows faster
synchronization of parallel operations, which results in lower response times to user queries. CPU
utilization and latency measurements with ServerNet II messaging show a three-fold improvement
over gigabit Ethernet and TCP/IP with the messaging loads just described. Published database
benchmark results demonstrate the value of SAN technology and efficient messaging to the
database cluster system.
C
O M P A Q
S
E R V E R
N
E T
I I T
E C H N O L O G Y
Compaq enterprise servers have long used
ServerNet
SAN technology to provide systems with
superior scalability, availability, and flexibility. ServerNet is the internal cluster interconnect
within several Compaq
NonStop
products. Compaq Himalaya systems with ServerNet SAN
messaging provide NonStop transaction services to Automatic Teller Machines, Stock Exchanges
and credit card processing for most financial communities and consumers worldwide. Compaq
Integrity products use ServerNet to achieve superior Unix availability to the telecommunications
industry. NonStop Cluster products based upon Compaq ProLiant servers and the SCO operating
system rely upon ServerNet for superior scalability and availability features. ProLiant Parallel
Database clusters use ServerNet for scalability.
The Compaq
ServerNet II
SAN interconnect is the most complete industry-standard
implementation of the VI Architecture specification. Compaq ServerNet II is a low-latency,
distributed memory fabric that uses low-cost, industry-standard components to provide highly
reliable server-to-server communication. ServerNet II technology leverages several features of the
VI Architecture that allow distributed applications to operate independent of the operating system
and avoid unnecessary CPU interrupts. CPU utilization measurements of small message (64 bytes)
latency show that ServerNet II messaging delivers over three times the performance of gigabit
Ethernet and TCP/IP. Because of this high-performance, ServerNet II SAN configurations can
scale to tens of servers within a cluster.
