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CSS Advanced Configuration Guide (Software Version 7.20)
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Index
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Preface
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Configuring the CSS Domain Name Service
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Configuring the DNS Sticky Feature
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Configuring a CSS as a Content Routing Agent
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Configuring a Client Side Accelerator
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Configuring Network Proximity
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Configuring VIP and Virtual Interface Redundancy
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Configuring Adaptive Session Redundancy
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Configuring Box-to-Box Redundancy
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Configuring Content Replication
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Configuring SSL Traffic through the CSS
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Configuring Firewall Load Balancing
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Using the CSS Scripting Language
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Using an XML Document to Configure the CSS
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Table Of Contents
Configuring a Client-Side Accelerator
Overview of Client Side Accelerator
Multiple-POP CSA Configuration
Configuring a DNS Server Forwarder
Configuring Accelerated Domains
Resetting the DNS Record Statistics
Configuring the CSA DNS Server Zones
Displaying a CSA Configuration
Displaying DNS Server Domain Cache Statistics
Displaying DNS Record Keepalive Information
Displaying Domain Acceleration Records Statistics
Configuring a Client-Side Accelerator
This chapter provides an overview of the CSS Client Side Accelerator (CSA) feature and describes how to configure it for operation. Information in this chapter applies to all CSS models, except where noted.
Note
The CSA feature is part of the CSS Enhanced feature set.
This chapter provides the following major sections:
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Overview of Client Side Accelerator
To accelerate the retrieval of domain content, configure a CSS as a CSA, using transparent caches (TCs) to store content locally. This feature improves a user's experience by reducing the time for content to arrive in a browser.
A CSA resides on the client side of the Internet and is the first DNS server to which clients send a DNS request. When a CSA receives a DNS request for content located in a domain configured for acceleration and the number of requests exceeds the configured threshold, the CSA returns an address record (A-record) of the local virtual IP address (VIP) to the client. The client uses the IP address in the A-record to connect to the service in a local TC farm.
For non-accelerated content or unresolvable DNS requests, the CSA sends the DNS request to a DNS server forwarder. The forwarder, which is not a CSS, is a fully-functional Berkeley Internet Name Domain (BIND) DNS server. The forwarder returns a DNS response to the client transparently through the CSA.
You can configure a peer mesh of multiple CSAs that belong to one service provider but are located at various points of presence (POPs). Using Application Peering Protocol (APP), the CSAs in a peer mesh share accelerated domain records. This allows you to leverage content available at a cache farm in one POP to provide content to clients located at another POP. Once the same candidate domain has been accelerated at two POPs, cache backup can occur if a cache at one of those POPs fails.
Service providers can use CSAs to bill back domain acceleration to content providers. You can configure certain domains for acceleration, then bill back content providers based on the number of hits on the accelerated domains.
Configuration Examples of CSA
This section describes two possible CSA configurations: the first, a single POP (Figure 4-1) and the second, two POPs using an APP peer mesh (Figure 4-2).
Single-POP CSA Configuration
The following sequence describes the steps depicted in :
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Figure 4-1 Example of a Client Side Accelerator Configuration Example
Multiple-POP CSA Configuration
The following sequence describes the steps depicted in Figure 4-2.
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Figure 4-2 Example of a Client Side Accelerator APP Mesh Configuration
CSA Quick Start
Table 4-1 provides a quick overview of the steps required to configure the Client Side Accelerator feature on a CSS. Each step includes the CLI command required to complete the task. For a complete description of each feature and all the options associated with the CLI command, refer to the sections following the table.
Table 4-1 Client Side Accelerator Configuration Quick Start
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# config (config)#2.
(config)# app3.
(config)# app session 192.160.1.24.
(config)# persistence reset remap(config)# bypass persistence disable5.
(config)# dns-record accel abc.com 192.168.1.1(config)# dns-record accel cbs.com 192.168.1.16.
(config)# dns-server accelerate domains 50 30 256 single_location7.
(config)# dns-server zone 1 tier28.
(config)# dns-server forwarder primary 192.168.1.109.
(config)# dns-server10.
(config)# service transHosttag1(config-service[transHosttag])# ip address 10.1.2.1(config-service[transHosttag])# protocol tcp(config-service[transHosttag])# port 80(config-service[transHosttag])# type transparent(config-service[transHosttag])# transparent-hosttag(config-service[transHosttag])# activeRepeat for each additional cache.
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(config)# owner accelerate(config-owner[accelerate])# content l5-accel(config-owner-content[accelerate-15-accel])# VIP address 192.168.1.1(config-owner-content[accelerate-15-accel])# protocol TCP(config-owner-content[accelerate-15-accel])# port 80(config-owner-content[accelerate-15-accel])# url "/*" eql cacheable(config-owner-content[accelerate-15-accel])# add service transHosttag1(config-owner-content[accelerate-15-accel])# add service transHosttagn(config-owner-content[accelerate-15-accel])# no persistent(config-owner-content[accelerate-15-accel])# balance url(config-owner-content[accelerate-15-accel])# active12.
(config)# service bypassCache(config-service[bypassCache])# ip address 0.0.0.0(config-service[bypassCache])# protocol tcp(config-service[bypassCache])# port 80(config-service[bypassCache])# keepalive type none(config-service[bypassCache])# bypass-hosttag(config-service[bypassCache])# active13.
(config)# owner accelerate(config-owner[accelerate])# content nonCacheable(config-owner-content[accelerate-nonCacheable])# VIP address 192.168.1.1(config-owner-content[accelerate-nonCacheable])# protocol TCP(config-owner-content[accelerate-nonCacheable])# port 80(config-owner-content[accelerate-nonCacheable])# url "/*"(config-owner-content[accelerate-nonCacheable])# add service bypassCache(config-owner-content[accelerate-nonCacheable])# no persistent(config-owner-content[accelerate-nonCacheable])# active
Configuring CSA Parameters
The following sections describe the CLI commands and their options and variables that you use to configure Client Side Accelerator on a CSS.
Enabling CSA
Use the dns-server accelerate domains command to enable the CSA functionality on a CSS. This command enables the acceleration of domains that have been or will be configured for acceleration using the dns-record accel command. The CSA uses the threshold variable to determine if it should accelerate a candidate domain. You can also configure whether or not the CSA shares content with peer CSAs.
The syntax for this global configuration mode command is:
dns-server accelerate domains threshold interval max_number [single_location|multi_location]
The variables and options for this command are:
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The following command example:
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(config)# dns-server accelerate domains 50 1 100 single_locationTo disable CSA functionality on a CSS, enter:
(config)# no dns-server accelerate domainsConfiguring the Domain Cache
Use the dns-server domain-cache command to enable the tracking of DNS request counts and to configure the domain cache on the CSA. As requests arrive at the CSA, entries are created or updated in the domain cache with the hit counts. You can use this command with the show dns-server domain-cache command to determine which domains you want to accelerate.
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The syntax for this global configuration command is:
dns-server domain-cache {cache_size ageout|purge {dns_name}|zero {dns_name}}
The variables and options for this command are:
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(config)# dns-server domain-cache purge ?•
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For example:
(config)# dns-server domain-cache 512The above command creates a domain cache that can hold up to 512 most recently requested domain entries. The entries will age out and be removed from the domain cache after 10 seconds (the default).
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Configuring a DNS Server Forwarder
Use the dns-server forwarder command to configure a DNS server forwarder on a CSS configured as a CSA. If the CSA cannot resolve a DNS request, it sends the request to the forwarder to obtain a suitable response. For details on configuring a DNS server forwarder, refer to Chapter 1, Configuring the CSS Domain Name Service, in the "Configuring a DNS Server Forwarder" section.
Configuring Accelerated Domains
Use the dns-record accel command to specify the domains you want to accelerate. Map the domain name to a content rule using an IP address.
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The syntax for this global configuration mode command is:
dns-record accel dns_name ip_address {ageout}
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The variables and options for this command are:
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The following command example creates an acceleration record for the domain abc.com. When the number of requests for the domain exceeds the threshold specified in the dns-server accelerate domains command, the CSA accelerates the domain for six minutes. Clients can access the domain's content based on the content rule with the IP address 192.168.11.1.
(config)# dns-record accel abc.com 192.168.11.1 6To delete the domain acceleration record, enter:
(config)# no dns-record accel abc.comResetting the DNS Record Statistics
Use the dns-record zero command to reset the DNS record statistics displayed by the show dns-record command. For details on resetting DNS record statistics, refer to Chapter 1, Configuring the CSS Domain Name Service, in the "Resetting the DNS Record Statistics" and "Displaying DNS-Record Statistics" sections.
Configuring the CSA DNS Server Zones
Use the dns-server zone command to configure the number of DNS server zones on a CSA. For details on DNS server zones, refer to Chapter 1, Configuring the CSS Domain Name Service, in the "Configuring DNS Server Zones" section.
Displaying CSA Information
Use the show commands in this section to display information and statistics for your CSA configuration.
Displaying a CSA Configuration
Use the show dns-server accelerate domains command to display the CSA configuration on a CSS. The syntax for this global configuration mode command is:
show dns-server accelerate domains
Table 4-2 describes the fields in the show dns-server accelerate domains output.
Displaying DNS Server Domain Cache Statistics
Us the show dns-server domain-cache command to display statistics for the DNS server domain cache. Use this command with the dns-server domain-cache command to help you determine which domains you want to accelerate. The syntax for this global configuration mode command is:
show dns-server domain-cache {summary}
Table 4-3 describes the fields in the show dns-server domain-cache output.
Table 4-3 Field Descriptions for the show dns-server domain-cache Command
Domain
The domain name of the entry
Counter
The number of DNS requests
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Displaying DNS Server Zones
Use the show zone command to display information about communication with, and the state of, the specified DNS zone or all zones in a peer mesh. For details on displaying DNS server zones, refer to Chapter 1, Configuring the CSS Domain Name Service, in the "Displaying DNS Server Zones" section.
Displaying DNS Record Keepalive Information
Use the show dns-record keepalive command to display DNS record keepalive information. For details on displaying DNS record keepalives, refer to Chapter 1, Configuring the CSS Domain Name Service, in the "Displaying DNS Record Keepalive Information" section.
Displaying Domain Acceleration Records Statistics
Use the show dns-record accel command to view statistics associated with domain acceleration records. The syntax for this global configuration mode command is:
show dns-record accel dns-name
The variable for this command is dns_name, the domain name mapped to the acceleration record that you want to display. Enter the name as a case-sensitive unquoted text string with no spaces and a maximum of 63 characters.
Table 4-4 describes the fields in the show dns-record accel output.
