Compaq 124708-001 - ProLiant Cluster - 1850, CL380 - ProLiant - 256 MB RAM, ProLiant CL1850, 124708-001 1850 White Paper

June 2000

Compaq Computer
Corporation

Prepared by
ISSD Technology
Communications

ONTENTS

C

Executive Summary .........1

Introduction.....................3

Traditional
Networks versus
System Area

Networks ..........................3

ServerNet II SAN Technology
Improves the Response

of Clusters ............................. 5

Compaq ServerNet

II Technology...................5

ServerNet II Hardware

Components..........................6

Low Latency Techniques

Improve Performa nce.............7

ServerNet II Performance

Summary...............................7

ServerNet II Leverages VI
Architecture Features to

Improve Scalability ................. 8

Fault Tolerance at All Levels..8
Operating System Vendor and

Independent Software

Vendor Support ..................... 8

The Future with

InfiniBand ........................9

Summary ..........................9

W

.

.

.

.

.

Compaq ServerNet II SAN Interconnect for

.

.

.

.

.

.

.

Scalable Computing Clusters

.

.

.

.

.

.

.

.

.

.

E

.

.

.

.

This paper introduces Compaq's ServerNet II system area network (SAN) interconnect

.

.

.

for use in scalable business computing clusters. Clusters generate intense server-to-

.

.

.

.

server messaging that can overwhelm traditional network technologies. The software

.

.

.

protocol overhead generated by traditional network technologies impedes server-to

.

.

.

server communication and limits the scalability, availability, and flexibility of clusters.

.

.

.

In contrast, the ServerNet II SAN interconnect is a high-bandwidth, low-latency network

.

.

.

.

technology that is proven to handle intense messaging in server clusters. A ServerNet II

.

.

.

SAN allows applications to be distributed over multiple servers, which increases cluster

.

.

.

scalability through greater parallelism and higher availability. The reader should be

.

.

.

familiar with the Virtual Interface Architecture.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

Please direct comments regarding this communication to the ISSD Technology Communications Group at this Internet

.

.

address: [e-mail]

.

.

.

.

.

.

HITE

XECUTIVE SUMMARY

P

APER

Doc Number

TC000602WP

1

HITE PAPER

W

.

.

.

OTICE

N

.

.

.

.

.

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 T HE 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 of product quality or correctness, nor does it ensure

.

.

.

compliance with any federal state or local requirements.

.

.

.

.

Microsoft, Windows, Windows NT, Windows NT Advanced Server, SQL Server for Windows NT

.

.

.

are trademarks and/or registered trademarks of Microsoft Corporation.

.

.

.

.

.

Novell and NetWare are registered trademarks and IntranetWare, NDS, Novell Directory Services,

.

.

.

GroupWise, BorderManager, and ManageWise are trademarks of Novell, Inc.

.

.

.

.

Pentium is a registered trademark of Intel Corporation.

.

.

.

.

.

Other product names mentioned herein may be trademarks and/or registered trademarks of their

.

.

.

respective companies.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

©2000 Compaq Computer Corporation. All rights reserved. Printed in the U.S.A.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

Compaq ServerNet II SAN Interconnect for Scalable Computing Clusters

.

.

.

First Edition (June 2000)

.

.

.

Document Number TC000602WP

.

.

.

.

.

(cont.)

Doc Number

TC000602WP

2

HITE PAPER

W

.

.

NTRODUCTION

I

.

.

.

.

.

The enterprise computing systems of many businesses were built around centralized, proprietary

.

.

.

computers, which are expensive to manage and upgrade. The networks that evolved around these

.

.

.

centralized systems use traditional network technologies such as Ethernet and TCP/IP, which are

.

.

.

designed for he terogeneous computing environments. T oday, businesses can satisfy their

.

.

.

computing goals with a collection of low-cost, industry-standard servers distributed within a

.

.

.

cluster. A cluster is a group of two or more interconnected servers that act as a single computing

.

.

.

unit. Servers in a cluster can be physically distributed across various locations, yet to a user, the

.

.

.

cluster appears as a single, unified computing resource. In a parallel application cluster, for

.

.

.

example, each server simultaneously runs a copy of an application and the operating system. Client

.

.

.

requests are divided among the servers’ CPUs (central processing units), and the servers exchange

.

.

.

information about the portion of the client’s request they are processing. If one server fails, the

.

.

.

jobs it was processing are distributed across the remaining servers. Consequently, clustered servers

.

.

.

collectively generate tens of thousands of messages per second to keep track of the jobs they are

.

.

.

executing.

.

.

.

.

.

The high volume of server-to-server messaging in a cluster requires a very efficient software

.

.

.

communication interface and a highly reliable, high-speed, low-latency hardware interconnect.

.

.

.

Without an efficient server-to-server interconnect, the performance and scalability of a cluster is

.

.

.

severely limited. Traditional network technologies produce excessive software overhead, due to

.

.

.

their heterogeneous environments, and are too inefficient for intense server-to-server

.

.

.

communication. Therefore, in December 1997 Compaq and other industry leaders developed the

.

.

.

Virtual Interface (VI) Architecture specification for a distributed messaging interface that allows

.

.

.

more efficient server-to-server communication through a system area network (SAN). The VI

.

.

.

Architecture provides a common software and hardware interface standard so that customers can

.

.

.

choose the optimum SAN interconnect (Compaq ServerNet II, gigabit Ethernet, cLAN, ATM, or

.

.

.

others).

.

.

.

.

.

The Compaq ServerNet II SAN interconnect is the most complete industry-standard

.

.

.

implementation of the VI Architecture specification. Measurement of CPU utilization under

.

.

.

certain conditions shows that ServerNet II provides three times the performance of gigabit Ethernet

.

.

.

and TCP/IP. As a result, ServerNet II is quickly emerging as the interconnect of choice for

.

.

.

implementing clusters of industry-standard servers. Operating system vendor and independent

.

.

.

software vendor support for ServerNet II includes Windows 2000 Data Center, Windows 2000

.

.

.

Advanced Data Server, Linux, and SCO UnixWare 7.1.

.

.

.

.

.

.

.

RADITIONAL NETWORKS VERS US SYSTEM AREA

T

.

.

.

ETWORKS

N

.

.

.

.

Clustered servers can communicate with each other by using a traditional network or a SAN.

.

.

.

Traditional network technologies allow several different types of devices to communicate with each

.

.

.

other in comple x, heterogeneous networks. Network ap plications manage communications

.

.

.

between the devices using multipoint protocols like TCP/IP and network interface controllers.

.

.

.

These protocols generate a large amount of software overhead (error checking and control

.

.

.

.

information) to ensure that messages are sent and received reliably. This software overhead

.

.

.

continually interrupts the servers’ CPUs. Consequently, the high volume of server-to-server

.

.

.

messaging in a cluster can overwhelm traditional network protocols like TCP/IP. In fact, clusters

.

.

.

that use traditional networks for messaging can lose as much as 20 to 30 percent of their capability

.

.

.

during intense messaging. This loss of system capability results in slower response times for users

.

.

.

and reduces the scalability, availability, and flexibility of clusters. When you consider the

.

.

.

unpredictable nature of Internet traffic, it becomes apparent that traditional network technologies

.

.

.

cannot handle se rver-to-server messaging in e-commerce environments.

.

.

.

.

.

.

(cont.)

Doc Number

TC000602WP

3