Produttore : HP File Size : 136.55 kb File Nome : Lingua di insegnamento:

Vai a scaricare

WHITE PAPER (cont.)
.
.
.
. I N T R O D U C T I O N
.
.
.
. 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 heterogeneous computing environments. Today, 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.
.
.
.
.
.
.
. T
.
R A D I T I O N A L N E T W O R K S V E R S U S S Y S T E M A R E A
.
. N E T W O R K S
.
.
.
.
. 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 complex, heterogeneous networks. Network applications 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 server-to-server messaging in e-commerce environments.
.
.
.
.
.
Doc Number TC000602WP
3

---

...

Questo manuale è adatto anche per i modelli :
Computer - Compaq ProLiant CL1850 Server (136.55 kb)
Computer - HP ProLiant DL2x170h G6 Server (136.55 kb)

Scarica la tua

Per scaricare, digitare 2 cifre :