Hp COMPAQ PROLIANT 1500, COMPAQ PROLIANT 4000, COMPAQ PROLIANT 4500, COMPAQ PROLIANT 5000, COMPAQ PROLIANT 5500 ServerNet - A High Bandwith, Low Latency Cluster Interconnection

White Paper

September 1998
ECG097/0998

ServerNet - A High Bandwith,

Prepared by Industry Standard
Server Division

Compaq Computer Corporation

Contents

Clusters – an Emerging
Paradigm in the Intel NT

Server Marketplace.....................3

ServerNet: The Interconnect
Vehicle for Enterprise

Clusters......................................3

ServerNet Initial Concept ..........3

ServerNet as Industry

Standard...................................4

Customer Benefits Using

ServerNet Technology................ 4

ServerNet and Virtual

Interface Architecture (VI)..........5

Advantages of Using
ServerNet to Meet the
Interconnect Technology

Requirements of Clusters .......... 6

Conclusion .................................8

For More Information..................8

Low Latency Cluster
Interconnection

This paper provides an overview of ServerNet technology, what benefits can
be realized from ServerNet in clustered server SANs, and how Compaq is
implementing SAN concepts using ServerNet as the primary cluster
interconnect for its enterprise vision of the future.

Abstract: Clustering is mentioned almost everywhere in current computer

industry news, but it is more than just linking computers. Enabling
enterprise-ready cluster solutions requires reliable, scalable interconnect
architecture and robust, parallel software.

The computer interconnect technology is the nerve system of a cluster,
tying together all its various components - servers, storage, networks, and
other system resources. There are many possible cluster interconnect
technologies—Ethernet, asynchronous transfer mode (ATM), and other
high-speed services. One of the emerging technologies is ServerNet,
representing the industry’s first System Area Network (SAN) solution,
which offers fault-tolerant high bandwidth and extremely low latency for
distributed message passing and clustered server communications.

ServerNet, a new open systems approach for high-speed interconnection of
both shared-disk and shared-nothing clusters, considers all the major
components of the system as independent elements so that any cluster
component—server, disk, or I/O device—can directly communicate with
any other component without processor intervention.

The benefits of ServerNet inter-processing communications include high
speed, low latency communications with the added benefit of truly non-stop
interfaces through the multi-plane ServerNet Switch. These hardware
features, in conjunction with the developing Thin Winsock-2 and VI
protocol architectures for distributed application and parallel processing,
make ServerNet an ideal candidate for inter-processor and cluster
communications.

As ServerNet evolves from the ProLiant Cluster Series F and continues to
scale into larger clustered server configurations, such as the VI - SAN
technology demonstration using IBM Universal Database Version 5.1 and
Compaq’s industry leading cluster TPC-C benchmark, this technology can
continue to establish itself as the industry standard cluster interconnect.

ServerNet - A High Bandwith, Low Latency Cluster Interconnection 2

Notice

The information in this publication is subject to change without notice and is provided “AS IS” WITHOUT
WARRANTY OF ANY KIND. THE ENTIRE RISK ARISING OUT OF THE USE OF THIS
INFORMATION REMAINS WITH RECIPIENT. IN NO EVENT SHALL COMPAQ BE LIABLE FOR
ANY DIRECT, CONSEQUENTIAL, INCIDENTAL, SPECIAL, PUNITIVE OR OTHER DAMAGES
WHATSOEVER (INCLUDING WITHOUT LIMITATION, DAMAGES FOR LOSS OF BUSINESS
PROFITS, BUSINESS INTERRUPTION OR LOSS OF BUSINESS INFORMATION), EVEN IF
COMPAQ HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

The limited warranties for Compaq products are exclusively set forth in the documentation accompanying
such products. Nothing herein should be construed as constituting a further or additional warranty.

This publication does not constitute an endorsement of the product or products that were tested. The
configuration or configurations tested or described may or may not be the only available solution. This test
is not a determination or product quality or correctness, nor does it ensure compliance with any federal
state or local requirements.

Product names mentioned herein may be trademarks and/or registered trademarks of their respective
companies.

Compaq, Contura, Deskpro, Fastart, Compaq Insight Manager, LTE, PageMarq, Systempro, Systempro/LT,
ProLiant, TwinTray, ROMPaq, LicensePaq, QVision, SLT, ProLinea, SmartStart, NetFlex, DirectPlus,
QuickFind, RemotePaq, BackPaq, TechPaq, SpeedPaq, QuickBack, PaqFax, Presario, SilentCool,
CompaqCare (design), Aero, SmartStation, MiniStation, and PaqRap, registered United States Patent and
Trademark Office.

Netelligent, Armada, Cruiser, Concerto, QuickChoice, ProSignia, Systempro/XL, Net1, LTE Elite,
Vocalyst, PageMate, SoftPaq, FirstPaq, SolutionPaq, EasyPoint, EZ Help, MaxLight, MultiLock,
QuickBlank, QuickLock, UltraView, Innovate logo, Wonder Tools logo in black/white and color, and
Compaq PC Card Solution logo are trademarks and/or service marks of Compaq Computer Corporation.

Microsoft, Windows, Windows NT, Windows NT Server and Workstation, Microsoft SQL Server for
Windows NT are trademarks and/or registered trademarks of Microsoft Corporation.

NetWare and Novell are registered trademarks and intraNetWare, NDS, and Novell Directory Services are
trademarks of Novell, Inc.

Pentium is a registered trademark of Intel Corporation.
Copyright ©1998 Compaq Computer Corporation. All rights reserved. Printed in the U.S.A.
Information from this paper was compiled from information found on websites and includes news releases,

product summary sheets, product guides, and technical papers.
ServerNet - A High Bandwith, Low Latency Cluster Interconnection

White Paper prepared by Industry Standard Server Division
First Edition (September 1998)

Document Number ECG097/0998

ECG097/0998

ServerNet - A High Bandwith, Low Latency Cluster Interconnection 3

Clusters – an Emerging Paradigm in the
Intel NT Server Marketplace

Microsoft’s Windows NT Server has established itself as an easy-to-use, easy-to-program
operating system running on open industry PC hardware. But for the Windows NT Server
platform to move into the area of essential business computing, information technology
professionals need to see systems that exhibit true enterprise-level availability and scalability.

Clustering has its roots in fault-tolerant, massively parallel computing. Today, the computer
industry understands that greatly enhanced scalability and reliability can be realized through the
clustering of multiple small-scale, thus low-cost, Symmetric Multiprocessor (SMP) nodes and, in
some cases, single processor nodes.

Intelligent middleware, distributed databases, and high-speed interconnect technologies are now
falling into place to support clustered environments. Microsoft has embraced the cluster paradigm
for Windows NT Server and is providing the requisite operating system-level functionality while
supporting the development of standard clustering services for the Windows NT Server platform.

Microsoft Cluster Server (MSCS) technology is a key enabler of clustering in the Windows NT
Server environment. However, it is only the software component of the solution. Hardware
models and interconnect schemes such as ServerNet, along with software message passing
architectures such as Virtual Interface Architecture (VI) will ultimately define cluster
performance, scalability, and reliability.

ServerNet: The Interconnect Vehicle for
Enterprise Clusters

Traditional local and wide area networking technologies, which may make suitable client
connections, are often too slow to provide effective inter-server communications. These
technologies do not provide sufficient performance due to their heritage of involved
communication protocols and secure message-passing architectures. These technologies can
burden the cluster’s servers with significant protocol overhead when trying to provide high
bandwidth and throughput.

These operating characteristics necessitated a new approach to meet the needs of both shared-disk
and shared-nothing clusters. This new concept, the industry’s first, is referred as a System Area
Network (SAN), and encompasses a high speed, low latency transfer mechanism. ServerNet is
Compaq’s current choice as a SAN vehicle.

ServerNet Initial Concept

The concept of a high-speed, non-blocking inter-processor link was first developed by Tandem, a
division of Compaq Computer Corporation, as a proprietary solution to meet a fault-tolerant
clustering requirement. This concept was to satisfy requirements of no transaction or data losses
due to a system error. ServerNet was designed from the ground up to provide the low latency,
reliability, and scalability that are essential for high-end, commercial applications. The initial
implementation was not only for inter-processor communications keeping clustered applications
and server nodes in step, but also as a fault-tolerant link to data storage and networking.

ECG097/0998