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
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any time, without notice.
Copyright © 2000, Intel Corporation.
*Other brands and names are the propert y of thei r respectiv e owners.
Intel Corporation
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A20163-002 November 29, 2000
Table of Contents
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
ii
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
iv
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
2
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
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C H A P T E R 1Intel® NetStructure™ 7195 Multi-Site Traffic Director User Guide
Notes
4
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.
6
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.
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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.
8
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
9
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.
10
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
11
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
12
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.
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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.
1
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.
14
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.
1.
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.
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C H A P T E R 2Intel® NetStructure™ 7190 Multi-Site Traffic Director User Guide
Notes
16
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
name: lb1
generic load balancer
IP address 10.54.67.3
name: isvg1
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
name: isvg2
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
name: lb2
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.
18
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
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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
20
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
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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
22
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
2.
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.
2
. To include standby VIPs, type config
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