Intel 7190 User Manual

Intel® NetStructure™ 7190 Multi-Site Traffic Director

User Guide

Intel® NetStructure™ 7190 Multi-Site Traffic Director v.3.1.1

User Guide

Technical Product Notice

Information in this docume nt is provided in connection with Intel® products. No license, express or imp lied, by estoppel or otherwise, to any intellectual prope rty rights is granted by this document. Excep t as provided in Intel’s Terms and Conditions of Sale fo r such products, Intel assumes no liability whatsoever, and Intel disclaims any express or implied warranty, relating to sale and/or use of Intel® products including liability or warranties relating to fitness for a particular purpose, merchantability, or in fringement of any patent, copyright, or other intellectual property right. Intel products are not intended for use in medical, life saving, or life sustaining applications.

Intel may make changes to specificat ions and prod uct descriptions at any time, without notice.

*Other brands and names are the propert y of thei r respectiv e owners.

Intel Corporation Network Equipment Division 13280 Evening Creek Drive San Diego, California 92128-4102 USA Main: (858) 391-1900 Fax: (858) 391-1920

A20163-002 November 29, 2000

Chapter 1 Introduction 1

What is an Intel® NetStructure™ 7190 Multi-Site Director? . . . . . . . . . . . . . . . . . . 1

Two Versions of the 7190 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Who Should Use This Book . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

User Guide Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Chapter 2 Theory of Operations 5

“Intelligent” DNS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Traditional DNS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Multi-Site Traffic Management Using Intel Load Balancers . . . . . . . . . . . . . . . . . 8

Typical Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Site Balancing Methods. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Partial Failures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Intel® NetStructure™ 7190 Multi-Site Traffic Director User Guide

Chapter 3 CLI Configuration 17

Custom/Manual Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Adding Secondary 7190(s). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Commit the Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

NSLookup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Configure DNS Servers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Chapter 4 Multi-Site Scenarios 25

Scenario 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Part 1 – Initial Configuration of a Simple Site. . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Part 2 – Changing to Flash Response Mode Balancing. . . . . . . . . . . . . . . . . . . . . 31

Part 3 – Adding Load Balancers to an Existing Site . . . . . . . . . . . . . . . . . . . . . . . 32

Scenario 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Configuring in a Mixed Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Chapter 5 Boot Monitor 47

System Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Accessing the Boot Monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Boot Monitor Command Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Chapter 6 CLI Reference 59

Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Editing the Command Line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

Command History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Pipes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Online Help . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Command Line Syntax. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

CLI Command Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Objects and Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Global System Commands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

File Management Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

Configuration Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

Show Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119

Table of Contents

Chapter 7 SNMP Support 133

Standards Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133

Intel® MIB Tree . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133

Supported MIBs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134

Where to find MIB Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134

Agent Metrics Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136

Service Metrics Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137

ISV Metrics Group. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137

Site Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138

SNMP Traps. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139

Displaying SNMP Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141

Configuring Community Authentication & Security Parameters . . . . . . . . . . . . 141

Configuring Trap Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142

Configuring Other SNMP Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143

Chapter 8 Software Updates 145

Multiple Software Images . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145

Software Image Media . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145

Saving Your Current Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146

Downloading and Installing the Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146

Rebooting with the New Image and Verifying Installation . . . . . . . . . . . . . . . . . . 147

Restoring Your Previous Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147

Appendix A Diagnostics 149

Diagnostic LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149

Power Indication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150

Boot-time LED Diagnostics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150

Runtime LED Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151

Runtime Activity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151

System Log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152

Log Message Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152

Displaying Log Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152

Appendix B Cleaning the Dust Filter 157

Appendix C Regulatory Information 159

iii

Intel® NetStructure™ 7190 Multi-Site Traffic Director User Guide

Appendix D Terms and Conditions and Software License 169

Glossary 177

Support Services 181

Index 185

Introduction

What is an Intel® NetStructure™ 7190 Multi-Site Director?

The Intel® NetStructure™ 7190 Multi-Site Traffic Director is a global site balancer. It gathers your geographically dispersed data sites into multiple “virtual servers,” thus giving you multifaceted, centralized control over widely distributed resources.

Performance

The 7190 looks at individual client requests and matches them up with the best of many geogra phically dispersed fulfill ment sites using the selection method most appropriate to your specific needs.

Reliability

The 7190 supports active-active redundant mode, meaning that multiple, active 7190s can be used simultaneously. When one fails, any remaining 7190s continue operation.

C H A P T E R 1Intel® NetStructure™ 7195 Multi-Site Traffic Director User Guide

Scalability

Two Versions of the 7190

The 7190 can work cooperatively with up to fifteen other 7190s in deployment across sites. A site may be managed by any Intel NetStructure™ e-Commerce Traffic Director or Intel NetStructure™ Commerce Director, whic h can in turn intell igently manage server farms, and return serve r performance data to the 7190. The 7190 also supports sites th at do not have an Intel

load balancers.

Flexibility

The 7190 offers six distinct methods of balancing your distributed resources, ensuring a solution for your multi-site pro bl ems.

There are two versions of the 7190 . One uses strong encrypt ion (128bit encryption) and the other uses weak encryption (56-bit encryption). The 7190 version that may be exported to certain countries is subject to U.S. export restrictions.

Who Should Use This Book

This user guide is intended for network administrators with a basic knowledge of:

• Networking concepts and terminology

• Network topologies

• IP routing

• DNS and BIND

User Guide Summary

In addition to this int roductio n, the user guide co ntains the followi ng chapters:

• 7190 Theory of Operation

An overview of the multi-site network, the 7190’s place in it, and some concepts you need to know to use the unit effectively

C H A P T E R 1 User Guide Summary

• CLI Configuration

Instructions on how to use the Command Line Interface (CLI) to manually configure additional sites, agents, zones, and services.

• Multi-Site Scenar ios

Descriptions of several typical multi-site challenges accompanied by their corresponding 7190 solutions

• Boot Monitor

An explanation and reference of the 7190’s configuration commands

• CLI Reference

Detailed descriptions of the 7190’s operational commands, including tree illustrations of the command system structure

• SNMP Suppor t

Details of 7190’s SNMP capabilities

• Software Updates

Software update procedures

• Diagnostics (Appendix A)

How to interpret the 7190’s LED display

• Cleaning the Dust Filter (Appendix B)

• Regulatory Information (Append ix C)

• Terms and Conditions (Appendix D)

End user terms, conditions, and licensing information

• Glossary

• Support Services

• Index

C H A P T E R 1Intel® NetStructure™ 7195 Multi-Site Traffic Director User Guide

Notes

Theory of Operations

NOTE: Intel Load Balancer refers to either Intel®NetStructure™ 7180/7185 e-Commerce Directors or the Intel®NetStructure™ 7140/7145/7170/7175 Traffic Directors.

Typical load balancers work by balancing traffic over a Local Area Network (LAN) to a Web farm. The Intel Multi-Site Traffic Dire ct or extends this balancing to multiple sites over a Wide Area Network (WAN). By balancing referrals to each site, the 7190 enables enterprises and Web hosting services to integrate geographically distributed content and services.

The advantages of such integration are many, including:

• There is increased fault tolerance and availability owing to

redundant sites . Multiple ac tive sites per mit uninterr upted servic e in the event of a localized outage in the data network.

• Customer response times are improved by directing users to

uncongested sites or data centers.

• Easy scaling of server farms can be accomplished.

Multi-site load balancing works best in concert with Intel® load balancers. The 7190 also support s multi-site load balancin g with sites that do not have Intel load balancers. In this case, the sites are balanced on the basis of availability, and not based on proprietary metric information.

® NetStructure™ 7190

C H A P T E R 2Intel® NetStructure™ 7190 Multi-Site Traffic Director User Guide

“Intelligent”

DNS

Traditional DNS

The 7190 leverages the DNS architecture and proto col as the basis for its site balancing operations. Based on the info rmation gathered from all sites, the 7190 returns the address of the site that best meets the criteria for fulfilling t he request.

Traditional, or Round Robin, Domain Name Service (DNS) is a rudimentary means of server load balancing. Under this method, a single hostname is mapp ed to a list of multiple server IP addresses. When the DNS server resolves a request for that hostname, it return s the entire list to the requestor, then sorts it (the first name drops to the end of the list). Upon recei vi ng the l ist , the cl i ent requ esto r t ypi cal ly uses the first address. The next requestor of the ho stname receives the resorted list, and again most likely u ses the current first name. The list is resorted again, so that each sequential request sees a different “first choice” than the previous one. The chief benefit of Round Robin DNS is that it allows requests to be distributed to multiple hosts and, in theory, provides a layer of redundancy. On the negative side, the DNS server has no knowledge of the status of the sites to which it sends requests. Receiving sites may be heavily loaded or dead, thus the potential is high for unacceptably slow replies error messages to clients, which is out of the site operator’s control.

C H A P T E R 2 Traditional DNS

7190

7140/7170

(Los Angeles)

Client

(San Diego)

7140/7170

(Chicago)

ns.mstd-ex.com (Chicago)

Authority for msd-ex.com

Local DNS server

(San Diego)

Multi-Site Load Balancing

Authoritative DNS Servers

The DNS maps, or “resolves” hostnames into IP addresses. It is, in effect, a distributed database operating through a distributed, hierarchical system of Domain Name Servers. Thus, if t he local DNS server cannot resolve a name, it looks “upstream” to consult a R oot Domain Server for help. The Root Domain Server in turn asks the Authoritative Name Server (i .e., th e owner of t he name i t is tryi ng to resolve) to return the appropriate IP address for the requested name.

To illustrate

1. The client sends a query to its configured DNS (all clients are configured with the address of their DNS server) to resolve a particular domain name (e.g., www.mstd-ex.com).

2. The client DNS server sends a query to the Root Domain server for the .com domain (every DNS server is configured with the root server information) to resolve mstd-ex.com.

3. The Root Domain server responds with the address of the Authoritative DNS server fo r the mstd-ex.com domain.

C H A P T E R 2Intel® NetStructure™ 7190 Multi-Site Traffic Director User Guide

4. The client DNS server sends a query to the mstd-ex.com Authoritative DNS server to resolve www.mstd-ex.com.

5. The Authoritative DNS server responds to the client DNS server with the IP address of www.mstd-ex.com.

6. The client DNS server responds to the client with the IP address of www.mstd-ex.com.

In the discussion above , the 7190 acts as autho ritative DNS server f or

zone.mstd-ex.com, which is the zone in which the name www.mstd- ex.com resides.

Multi-Site Traffic Management Using Intel Load Balancers

Multi-site load balanc ing solves most of the prob lems inherent in Round Robin DNS. Under the server load balancing model, servers are aggregated in a “server farm” behind a lo ad balan cer kn own by a Virtual IP address or “service.” (The service is the IP address of which the external network is aware.) By keeping track of such metrics as number of connections, which services are running, response time and the like, the load balancer knows the status of the servers. The 7190 retrieves metrics from the load balancer. Thus, when a client requests the service, the 7190 routes it to the site who has a server best able to fulfill it.

If the data center has an Intel Load Balancer, the 7190 works in concert with the “agents” in the load balancers by continually communicating with each site’s agent through site verification protocol. This keeps the 7190 informed of the following:

• Health of the load balancers.

• Individual service health and availability.

• CPU utilization of load balancers (as of 7140/7170, 7180

Software release 2.2.1)

• Response time for each service (as of 7140/7170, and 7180

software release 2.3)

• Number of connections to each load balancers (as of 7140/7170,

and 7180 software release 2.2.1)

Site verification protocol information is encrypted for secure communication between an Intel Load Balancer and the 7190.

C H A P T E R 2 Typical Configuration

Multi-Site Traffic Management Without NetStructure Load Balancers

The 7190 can support data centers, whether or not they have an I ntel Load Balancer. Without these Intel products, the 7190 can monitor site service availability by using an ISV method:

• Ping (ICMP)

• TCP Open probe

• HTTP URL probe

Typical Configuration

Los Angeles location Chicago location

servers

The 7190 can be used with a wide variety of topologies but a basic example of a 7190 conf iguration mig ht consist of t wo 7190s and four NetStructure 7140s (one 7190 at each location that the site is distributed across, and two 7140s in serial fail-over mode for each location). For illustrative purposes, these devices are configured to balance www.mstd-ex.com. Because the 7190 does not resolve records aside from hostnames (e.g., no MX records or reverse DNS lookups), your existing DNS server should remain authoritative for the domain, mstd-ex.com. A new zone, zone.mstd-ex.com, must be created and your existing DNS server must delegate authority for this zone to all

of the 7190s. An alias, www.zone.mstd-ex.com is created for www.mstd-ex.com. This zone and alias are transparent to users connecting to your site. They still requests www.mstd-ex.com and are referred to the optimal site by the 7190.

Intel

7190 primary

Internet

7180s

Clie nt

7190 secondary

7180s

servers

7190 Overview - A Basic Configuration

C H A P T E R 2Intel® NetStructure™ 7190 Multi-Site Traffic Director User Guide

Site Balancing Methods

The 7190 supports six site-balancing methods or algorithms. The operator chooses the method most appropriate to the deployment to optimize traffic volume, priority, resource availability, and the overall desired outcome.

Weighted Algorithms

• Weighted Round Robin - Two differences distinguish this

method from traditional, or round robin, DNS. First, the 7190 is aware of the status of the sites it balances thus, unlike legacy Round Robin, it does not indiscriminately send requests to servers that have gone down or are otherwise unable to fulfill requests. Second, weighted round robin allows the operator to skew the loading among availabl e sit e servi ces on t he basi s of a n assigned “weight.” (Weight takes into account differences in capabilities of site services.) Weighting allows the operato r to adjust loading on a percentage basis. For example, Site A is assigned a weight of 1, Site B, 2, and Site C, 7. Thus, Site A receives 10% of the traffic, Site B, 20% and Site C, 70%. This method can ensure the most efficient use of those sites with greater “horsepower,” while preventing the overtax ing of less powerful ones.

• W eighted Random - T he Weighted Random method is similar to

Weighted Round Robin with the exception that requests are not fulfilled serially. IP addresses are resolved in a random fashion. The weighting is accomplished as above. The benefit of this algorithm is that it is more effective at n ormalizing, or leveling, load.

Metric Algorithms

Using DNS to balance multiple sites is more effective when the referrals are based upon knowled ge of the actual loads on the servers. In addition, balancing effect ivene ss no ti ceab ly i ncrease d whe n b ackto-back referrals to the same site were not made even if metrics indicated one site service was the best both times. The 7190 metric algorithms reflect both of those findings.

These balancing algori thms are not availa ble for sites that do not have Intel load balancer s:

• Response Time - The Response Time method directs requests to

the site that has the fastest aggregate (i.e., across all servers) response time for the requested service. Likely users of this method are enterprises that have identified the efficient

C H A P T E R 2 Site Balancing Methods

fulfillment of a specific type or types of traffic as being crucial to their business goals. (Available with the 7140/7170, 7180 2.3 release.)

• Least Connections - The Least Connections method sends

requests to the site with lowest number of connections. This method permits the most efficient management of requests that are likely to require connections of long duration, such as FTP. (Available with the 7140/7170 and 7180 releases.)

• CPU Utilization of Local Load Balancer - This method directs

clients to the site whose load b a lancer has the lightest workload. The benefit of this method is most evident when used wi th sites performing processor-intensive Layer 7 load balancing. (Available with the 7170 2.2.1 release.)

Managing Unequal Site Servers

There is a “factor” command to determine a threshold factor in the event of two unequal servers. (see config dns zones <zonename> hostnames <hostname> siteservices <siteservicename> factor in Chapter 5, “CLI Reference.”)

The 7190 determines which IP address to return for a hostname, based on the performance of the IP address and port at a site. The three-step process is:

1. Determine the metric(s) with the smallest value.

2. Determine whether any remaining service(s) are close enough to

this best value to also be co nsidered. The quantifi cation of “close enough” is the factor. A factor o f 0 means con sider only services with the best value.

3. Randomly choose from all the services identified in the first two

steps.

A good example of the usefulness of this “close enough” threshold factor is when two unequal servers are deployed behind di fferent load balancers. Server A may be capable of handling 3000 connections per second. Server B may also be capable of handling that many connections per second, but is also servi ng more sites than Server A. The realistic connection limit of Server B may therefore only be about 500 connections per second. If Server A has 900 connections and Server B has 400 connections, then Server B is the site with the least number of connections, alth ough it is already 80% load ed while Server A is only 30% l oad ed. The better choice woul d be to give the traffic to server A. However , the 7190 has no knowled ge of the actual

C H A P T E R 2Intel® NetStructure™ 7190 Multi-Site Traffic Director User Guide

load potential of the serve r s underneath the load balanc ers it monitors. Therefore it allows the next best thing. For example, it allows the user to declare that if Server A is within 24 00 connections (80% of maximum) of Server B, consider referrals to Server A even if Server B is the lowest. The factor setting would be 2400 for the service associated with Server A and 0 for the service associated with Server B.

Flash DNS

Network topology can greatly affect the overall transfer rate between a site and a client. A solution is to replicate sites on multiple networks (which are sometimes also distributed geographically). Without a 7190, it can be cumbersome to provide users with a list of mirror sites and then let them choose which one appears to be best for them.

Flash DNS addresses this probl em b y l et ting a 7190 at each network site send out responses to a DNS query for the site host name. If all responses are sent at the same time then the site that has the least network latency connectin g t o t he user should get its response to the user first. The user ignores all the other responses.

Partial Failures

Since many enterprise clients are behind firewalls that perform Network Address Translation (NAT), by default, the 7190 performs source IP using the IP address of the 7 190 that ori ginally receiv ed the DNS request. This feature can be disabled.

The 7190 maintains the current metric state of each service on a per host basis. A “service” is an IP address and port at a site. The maintained state has four levels relating to the amount of information that the 7190 has about each service.

Each load balancin g method handles parti al failures in t he same basic way. Each balancing method always tries t o f ind at l east one servi ce with a metric status of “OK” with which to balance. If no services are available at this highest metric state, and it is not using a metric balancing method, then it looks for at least one service with a metric state of “No Services”. If none are found t hen it look s for at lea st one service with a metric state of “No Metrics”. Finally, if no services have been found at a high enough metric state level to balance normally, it performs a round robin selection among all the enabled services.

C H A P T E R 2 Partial Failures

Status: OK

This state indicates that the required services behind this service are available on the associated load balancer. The metrics information for this service are current and can be used for metric load balancing.

Status: No Services

This state indicates that services other than the one(s) configured as required for the associated host are not available on the load balancer. Other services with this same service are available. Metric load balancing is not available for this service.

Status: No Metrics

This state indicates that th e Intel Load Balancer is not advertising any services that use this service. Metric load balancing is not available for this service.

Status: No Connection

The 7190 has lost or been unable to establish a connection to the fulfillment agent on the load balancer. No metrics information on any services from this load balancer is available. No load balancing methods are available fo r t hi s ser vi ce. It may only participate i n nonweighted round robin load balancing.

Service Standby

To achieve site service redundancy, customers often want to have backup services that are completely dark to normal traffic, but are instantly available to take over for a failed site service. The transition of traffic from the failed site service to the standby site service occurs without the need of operator intervention.

The Service Standby feature allows the designation of a site’s services for standby. If there is a 7190 located at the site, its operation is unaffected and continues in resolving queries and referring to active services. When the 7190 has detected a failed service, the failed service is not used in referrals. Once a failed service has been deemed active again, no further referrals are made to the standby service.

The determination to use or not use a standby site service is only made upon receipt of a query that involves the service. Therefore, a standby service is not activated to replace a failed service until a query is received, and a failed service is not shown as active until after a query is received.

C H A P T E R 2Intel® NetStructure™ 7190 Multi-Site Traffic Director User Guide

Multiple VIP Response

The DNS response from a 7190 may contain multiple answers. The number of answers and whether to include stand-by VIPs can be configured.

Active VIPs are included first in the response. A stand-by VIP is treated as an active VIP, if it is marked as “IN USE” due to a failed VIP. Stand-by VIPs are included after the active VIPs: (a) if the configuration is se t to incl ude th em and, (b ) the number of req uested additional VIPs in the response has not been met.

When using mutli-VIP r esponse with Flash load balancing, the Flash response attemp ts to use VIPs wi thin the same pee r group first bef ore including VIPs from the other peer groups.

Definitions

Understanding of the 7190 requires some specialized terms. The definitions provided here are specific to the context of multi-site load balancing and the operation of the 7190, thus there may be subtle differences between these and those offered in other sources.

Agent is a component of an Intel Load Balancer that gathers metric data and transmits i t t o t he 7190 . For the purposes of the d iscussions in this user guide, “agent” is synonymou s with “Traffic Director” or “e-Commerce Director.”

Agent IP refers to the real IP address of an Intel Load Balancer in its role as an agent to a 7190.

Intelligent Site Verification (ISV) is used to directly determine the availability of (1) a service or, (2) a service that is balanced using a third-party Load Balancer. Methods of verification include a site ping, TCP connect, and HTTP probe.

ISV Group refers to a collection of services available at a physical site. All services in a group share th e same ISV polling parameters.

If multi-VIP standby is enabled when using the Flash load balancing method, standby VIPs from a site are not included if all of the VIPS are (1) standby and, (2) not marked “IN USE” due to a failed VIP at another site.

C H A P T E R 2 Definitions

Primary 7190 is a 7190 that automatically transfers (copies) configuration information to secondary 7190s (through the Global Sync process). Configuration may only be changed on a Primary

7190. Service is the Virtual IP (VIP) and port number of an application

service available at a site. Authoritative Server is a DNS name server that has co mplete name

space information regarding the hosts within a given zone (see below).

Authority is an attribute of a DNS name server with respect to a specific part of the DNS name space, or zone (see below). A name server is said to have authority over a zon e, by whi ch that se rver has complete name space information for that zone.

Zone is a portion of a DNS name space for which a given name server has complete name space information. When a name server receives a request for a host outside of its zone, it replies with the name of the name server that is authoritative for a different zone and is likely to have the specific inform a tion required to satisfy the request.

C H A P T E R 2Intel® NetStructure™ 7190 Multi-Site Traffic Director User Guide

Notes

CLI Configuration

Custom/Manual Configuratio n

You can manually change any specific configuration parameters if any of the Quick Start Wizard default settings are not sufficient for your site.

It is recommended that you use the custom configuration method only after you have comp leted the initial configuration with the Quick Start Wizard. See the Intel® NetStructure™ 7190 Multi-Site Traffic Director Getting Started Guide for instructions on using the Quick Start Wizard.

C H A P T E R 3 Intel® NetStructure™ 7190 Multi-Site Traffic Director User Guide

7190 (Primary)

host name: ns1.xyz-ex.com IP address: 10.54.67.2

7xxx Load Balancer

IP address 10.54.67.4

service VIP 10.54.67.5 port 80 service VIP 10.54.67.6 port 80

service VIP 10.54.67.7 port 255

service VIP 10.54.67.8 port 255

generic load balancer

IP address 10.54.67.3

Adding Secondary 7190(s)

Data Center 1

Network Topology

Map of

w ww.xyz-ex .co m

Data Center 2

generic load balancer

IP address 10.100.68.3

service VIP 10.54.68.7 port 255

service VIP 10.54.68.8 port 255

7xxx Load Balancer

IP address 10.100.68.4

service VIP 10.100.68.5 port 80

service VIP 10.100.68.6 port 80

7190 (Secondary & Peer)

host name: ns2.xyz-ex.com IP address: 10.100.68.2

Sample Network Topology

Now that the primary 7190 is up and running, the additional 7190s can be easily added by configuring them as secondary 7190s. They receive all their configuration information from the designated primary 7190 through the Global Sy nc proc ess, which aut omatic ally transfers the primary 7190 configuration to any secondary 7190s.

Similar to a typical DNS server, all 7190s are treated as equals by other DNS servers. The terms of primary and secondary only refers to where a 7190 gets its new configuration information. The 7190 only allows the configuration to be changed on a primary 7190. Secondaries get their configuration from their designated primary 7190 and store a copy of the recei ved configur ation loca lly. Shou ld a secondary be unable to con tact a primary i t fu nctio ns normal ly usi ng its stored configuration. All 7190s have the same picture of the current Agent metrics and are eq ually capable of r esponding. S hould one fail the existing DN S protocol automatic ally routes requests to the non-failed 7190s.

The theoretical secondary ns2.xyz-ex.com (IP 10.100.68.2) can resolve requests for www.somedomain.xyz-ex.com by becoming a secondary of the 7190 at 10.54.67.2. From the CLI on the proposed second 7190, execute the command:

C H A P T E R 3 Custom/Manual Configuration

NOTE: User-entered names and IP addresses in the example are for illustrative purpo ses only. The appropriate values for your installation may vary.

An Intel_7xxx Load Balancer refers to Intel®NetStructure™ 7180/7185 e-Commerce Directors or the Intel®NetStructure™ 7140/7145/7170/7175 Traffic Directors.

#config dns secondary 10.54.67.2 Warning: Your current dns configurations will

be lost. Are you sure you want to become a Secondary

(Yes/No):yes Now running as a Secon dary.

If the DNS configuration of 10.54.67.2 is changed, the new configuration can be prop agated to 10.100.68.2 by the commit all command.

Creating Agents

An agent refers to the Intel Load Balancers at each site. They are used to keep the 7190 informed of site status, response time, and number of current connections of the server farm they are balancing.

To add an agent, type the following:

Intel 7190# config dns agents create lb1 ip

10.54.67.4 Intel 7190# config dns agents create lb2 ip

10.100.68.4

Associating Services with Agents

Next, services must be associated with agent(s):

Intel 7190# config dns agents lb1 services create 10.54.67.5:80

Intel 7190# config dns agents lbi services create 10.54.67.6:80

Intel 7190# config dns agents lb2 services create 10.100.68.5:80

Intel 7190# config dns agents lb2 services create 10.100.68.6:80

Creating Zones

The next step is to create a zone (e.g., somedomain.xyz-ex.com) on the

7190. The command to do this is:

Intel 7190# config dns zones create somedomain.xyz-ex.com

C H A P T E R 3 Intel® NetStructure™ 7190 Multi-Site Traffic Director User Guide

NOTE: The 7190 must be authoritative for this zone—the existing DNS server should delegate the domain to the 7190.

Creating Authority Records

Next, authority records for your two 7190s are created. These sites are used to tell DNS servers who they can query directly for other hosts in the current zone. In order for the 7190 to perform effecti vely, only 7190s should be authoritative for the zone.

For example, hostname ns1.xyz-ex.com at IP address 10.54. 67.2 and hostname ns2.xyz-ex.com at 10.100.68.2. The authoritative DNS servers for xyz-ex.com should contain records for these hostnames, as well as the corresponding NS records for somedomain.xyz-ex.com. (See the section, Existing DNS Servers.)

Intel 7190# config dns zones somedomain.xyzex.com

7190/config/dns/zones/somedomain.xyz-ex.com#

create-author ity ns1.xyz-ex. co m ip

Create Authority Successful 7190/config/dns/zones/somedomain.xyz-ex.com#

create-author ity ns2.xyz-ex. co m ip

10.100.68.2

Create Authority Successful 7190/config/dns/zones/somedomain.xyz-ex.com#

info

Zone: somedomai nex.xyz-ex.co m Authority Records TTL: 7200 Authority Name: ns1.xyz-ex.com

Authority IP: 10.54.67.2 Authority Name: ns2.xyz-ex.com

Authority IP: 10.100.68.2 Zone = somedomainex.xyz-ex.com Authority Records TTL = 7200 Authority Name : ns1 .xyz-ex.com Authority IP: 10.54.67.2 Authority Name : ns2 .xyz-ex.com Authority IP: 10.100.68.2

10.54.67.2

C H A P T E R 3 Custom/Manual Configuration

Creating Hosts

Next, the hostname www.somedomain.xyz-ex.com is created:

7190/config/dns/zones/somedomainex.xyzex.com# hostnames create www

Create Hostname Successful

The next step is to map the services www.somedomain.xyz-ex.com to the load balancer. The following assumes the IP addresses of the load balancer to be 10.54.67.4 (service 10.54.67.5:80) and 10.100.68.4 (service 10.100.68.5:80), and that th e agents are enabled and run ning on the default port 1999. (Agents are enabled or disabled using the CLI of an Intel Load Balancer, with the command, config sys multisite <e nabl e|di sable> .) It is assumed t hat t he a gent names are the same as their IP addresses.

7190/config/dns/zones/somedomainex.xyzex.com# hostnames www siteservices

7190/config/dns/zones/somedomainex.xyzex.com/hostnames/www/siteservices# map

lb1:10.54.67.5:80

Site Service Mapped 7190/config/dns/zones/somedomainex.xyz-

ex.com/hostnames/www/vips# map

lb2:100.68.5:80

Site Service Mapped

Commit the Configuration

The commit command is used at this to point put the configuration into effect.

7190/config/dns/zones/somedomain.xyz-ex.com/ hostnames/www/vips# commit all

Warning: Your active configuration will be overwritten.

Are you sure you want to commit the configuration (yes|no)? yes

Configuration has been committed

C H A P T E R 3 Intel® NetStructure™ 7190 Multi-Site Traffic Director User Guide

NSLookup

Configure DNS Servers

NOTE: If the 7190 was not configured with a primary name server during setup from the Boot Monitor, the nslookup command fails.

The nslookup utility can verify that the 7190 is correctly resolving www.somedomain.xyz-ex.com:

Intel 7190# nslookup www.somedomain.xyz-ex.com

Server: server1.xyz-ex.com Address: 192.168.16.4

Name: www.somedomain.xyz-ex.com Address: 192.16 8.16.23

The existing DNS server or servers must be correctly configured to work with the 7190s. Entries need to be made that delegate the responsibility of resolving DNS queries for www.xyz-ex.com to the 7190s. This can be done in one of two ways. The first way is to delegate the entire zone to the 7190. This works fine as long as only type A records need to be returned for this zone. The 7190 is a high performance specialized DNS server and supports only the more common type A records.

The recommended way of configuring your existing DNS server is delegate partial auth ority by al iasing . All of the 7190s ( both primary and all secondaries) must be included in the authority record (NS) portion of the delegation.

Multiple-VIP Response

A DNS response may contain multiple answers. A standby VIP is automatically considered as a resp onse if it is marked “IN USE” due to a failed VIP. When multi-VIP standb y is enabled, standby VIPs are included in a response if the number of additional VIPs in the response has not been met

dns zones <zonename> hostnames <hostname> multi-vipstandby enable.

7190#config dns zones somedomain.xyz-ex.com hostnames www multi-vip-standby enable

. To include standby VIPs, type config

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