Manuale d’uso / di manutenzione del prodotto 1520 del fabbricante Intel
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Intel ® NetStructur e ™ 1520 Cache A ppliance Administr ator’ s Guide.
Copyright © 2000, Intel Corporation. All rights r eserved. Intel Corporation 5200 N. E. Elam Y oung P arkway Hillsboro, Oregon 97124-6497 No part of this publication may be reproduced, transmitted, t.
iii Contents Preface ix Who should read this manual ................................................................... x Conventions used in this manual .............................................................. x Chapter 1 Introduction 1 What is an Intel® NetStructure™ Cache Appliance? .
iv Intel NetStructure Cache Appliance Administrator’ s Guide iv Intel NetStructure Cache Appliance Administrator’ s Guide Using the ARM page .............................................................................. 21 Using the Other page ...
Contents v Chapter 5 Using the Command-Line Interface 49 Starting the command-line interface ....................................................... 50 Starting the appliance the first time .................................................. 50 Using the appliance after initial start-up .
vi Intel NetStructure Cache Appliance Administrator’ s Guide vi Intel NetStructure Cache Appliance Administrator’ s Guide Using the monitor menu ......................................................................... 99 Viewing Node statistics .
Contents vii Understanding cache hierarchies ......................................................... 135 HTTP cache hierarchies................................................................. 135 ICP cache hierarchies ..............................
viii Intel NetStructure Cache Appliance Administrator’ s Guide viii Intel NetStructure Cache Appliance Administrator’ s Guide Reaching the Cache page...................................................................... 21 Reaching the ARM page ..
Contents ix Preparing a cache disk ........................................................................... 61 Setting general controls .......................................................................... 62 Configuring HHTP options .........
x Intel NetStructure Cache Appliance Administrator’ s Guide x Intel NetStructure Cache Appliance Administrator’ s Guide Deleting ARM bypass rules .................................................................... 95 Viewing ARM bypass rules ....
xi Pr ef ace This manual describes ho w to use and configure an Intel ® NetStructure ™ Cache Appliance system (referred to as “appliance” in this manual) either as a single node or as a cluster of nodes. The manual cov ers the following topics: ◆ Chapter 1 contains an ov erview of the appliance and an ov erview of this guide.
xii Intel NetStructure Cache Appliance Administrator’ s Guide Who should read this manual This manual is intended for system administrators who configure, run, and administer Intel NetStructure Cache Appliance systems.
1 Chapter 1 Introduction The Intel ® NetStructure ™ Cache Appliance is a carrier-class caching appliance that of fers high performance, high av ailability , and simple centralized management. The appliance automatically and ef ficiently copies network documents and images, bringing them closer and serving them faster to your users.
2 Intel NetStructure Cache Appliance Administrator’ s Guide What is an Intel ® NetStructure ™ Cache Appliance? Internet users request billions of documents each day all ov er the world.
Chapter 1 Introduction 3 Server accelerator The appliance can be configured as a web server to accelerate slo wer traditional web servers. Documents stored in cache are serv ed at high speed, while documents not in cache are requested on demand from slo wer , traditional web servers.
4 Intel NetStructure Cache Appliance Administrator’ s Guide Multithreading pr ocess support The appliance is the first commercial caching proxy server to aggressi vely implement multithreading, breaking do wn large transactions into small, ef ficient tasks.
Chapter 1 Introduction 5 SNMP Network Management The appliance can be monitored and managed through SNMP network management facilities. The appliance supports two management information bases (MIBs).
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7 Chapter 2 Getting Star ted This chapter contains the follo wing sections: ◆ Starting the system for the first time‚ on pag e 8 ◆ Accessing the Manager UI‚ on pa ge 12 ◆ Accessing the comm.
8 Intel NetStructure Cache Appliance Administrator’ s Guide Starting the system for the first time Before you can start the Intel NetStructure Cache Appliance, make sure it is physically connected properly . Connections include: ✔ Connecting to the network through the primary network interf ace.
Chapter 2 Getting Started 9 4 After your system completes the boot procedure, a console login prompt appears with fields for both a login and password. At the prompt, supply admin for both the login and password, and press Enter . 5 After you login, the VT100 terminal emulator screen displays this initial set of menu selections.
10 Intel NetStructure Cache Appliance Administrator’ s Guide 11 Use the arro w keys to highlight timezone and press the Enter key . Pressing the Enter ke y causes a scrollable list of av ailable timzones to appear .
Chapter 2 Getting Started 11 installation, the bottom of the screen keeps you apprised of the installation’ s progress. 17 After the installation is complete, use the arro w ke ys to position the cu.
12 Intel NetStructure Cache Appliance Administrator’ s Guide Accessing the Manager UI The Manager UI is a bro wser-based interface, consisting of a series of web pages. Use the Manager UI to monitor performance and configure and fine-tune selected nodes in your cluster .
Chapter 2 Getting Started 13 F igure 1 The Dashboar d page Using Monitor and Configure mode The Manager UI has two modes, Monitor and Configure: ✔ In Monitor mode, vie w performance statistics and graphs. T o access Monitor mode, click the top of the MONITOR tab .
14 Intel NetStructure Cache Appliance Administrator’ s Guide F igur e 2 sho ws the control frame buttons for both the Monitor and Configure modes. F igure 2 The Monitor and Configur e Contr ol F rames When you are in Monitor mode, you can access all the pages that report information about the appliance’ s performance.
Chapter 2 Getting Started 15 Using online help Both the MONITOR and CONFIGURE tabs ha ve a Help page button. When you click the Help page button, the online help opens in another bro wser windo w . Each of the Manager UI pages has online help a v ailable.
16 Intel NetStructure Cache Appliance Administrator’ s Guide Administrator’ s ID and password for both telnet and Manager UI access as soon as possible after installing each node. T o change the password for the Manager UI, see Using the Security page‚ on page 39 .
17 Chapter 3 Monitoring Appliance Perf or mance This chapter describes ho w to use the Manager UI to collect and interpret performance statistics on the Intel NetStructure Cache Appliance.
18 Intel NetStructure Cache Appliance Administrator’ s Guide Accessing monitor pages The Manager UI uses monitor pages to present performance information on the selected appliance and the cluster as a whole. A monitor page is a bro wser page displayed as a result of “clicking” on a page button in the Manager UI.
Chapter 3 Monitoring Appliance Performance 19 Use the Dashboard page to: ✔ Select a node ✔ See which nodes are on and which are of f ✔ See if an alarm condition exists on an y node If an alarm condition exists, you can click the alarm light to vie w a description of the alarm and resolve it.
20 Intel NetStructure Cache Appliance Administrator’ s Guide ✔ Cache hit rate, refresh ✔ Errors ✔ Aborts ✔ Acti ve clients/serv ers ✔ A verage fresh hit Note Online help provides descriptions for each of these statistics.
Chapter 3 Monitoring Appliance Performance 21 Using the Graphs page The Graphs page provides a list of options for generating performance graphs for cache results, garbage collection, transfer rates, and object size for the currently selected node. ▼ Reaching the Graphs page 1 Be sure you are in monitor mode.
22 Intel NetStructure Cache Appliance Administrator’ s Guide ▼ Reaching the ARM page 1 Be sure you are in monitor mode. If not, click the MONITOR tab . 2 Click the Arm page button. Note Online help provides descriptions of each of the statistics in the ARM page.
23 Chapter 4 Configuring the Appliance This chapter describes the configuration options that control the Intel NetStructure Cache Appliance behavior and performance, and instructs you on ho w to set these values in the Manager UI.
24 Intel NetStructure Cache Appliance Administrator’ s Guide Accessing configure pages The Manager UI uses configur e pag es to display and allow configuration changes to the selected appliance. A configure page is a bro wser page displayed as a result of “clicking” on a configure page button in the Manager UI.
Chapter 4 Configuring the Appliance 25 Setting general options The follo wing table describes the general configuration settings in the Intel NetStructure Cache section. Option Description on/off Enables or disables caching. When you disable caching, you shut down all cache and proxy services on a node-by-node basis.
26 Intel NetStructure Cache Appliance Administrator’ s Guide Setting W eb management options The W eb Management section lets you restart the cluster and specify refresh rates as observed in monitor mode. The following table describes these configuration settings.
Chapter 4 Configuring the Appliance 27 The follo wing table describes the V irtual IP Addressing configuration settings. Adding entries to the Virtual IP address list Y ou can add or change entries in the V irtual IP address pool by modifying the appliance’ s V irtual IP address list.
28 Intel NetStructure Cache Appliance Administrator’ s Guide Setting browser auto configuration options The A utoconfiguration of Bro wsers section lets you specify an auto configuration file for the selected node. W eb bro wsers use the appliance by specifying a preference to use a proxy server , usually through an auto configuration file.
Chapter 4 Configuring the Appliance 29 ✔ If it takes the appliance more than 750 milliseconds, it be gins to shed 50% of its load. ✔ If the fresh-hit transaction time exceeds 1000 milliseconds, the appliance begins to shed 100% of its load.
30 Intel NetStructure Cache Appliance Administrator’ s Guide Using the Protocols page The Protocols page lets you vie w and change the selected appliance’ s protocol configuration. Y ou can tune HTTP , NNTP , and FTP timeout interv als; and configure the appliance to remov e HTTP headers from documents to protect site and user pri vac y .
Chapter 4 Configuring the Appliance 31 Configuring NNTP The NNTP section lets you configure basic NNTP options. While this section lets you configure basic options, you must use the command-line in.
32 Intel NetStructure Cache Appliance Administrator’ s Guide The follo wing table describes the options. Option Definition NNTP Server on/off Enables or disables the appliance to cache and serve news articles. After turning NNTP on or off for the selected node, you must restart the cluster to effect the change.
Chapter 4 Configuring the Appliance 33 NNTP options (continued) ❚ Background Posting: Causes the appliance to post NNTP articles to parent NNTP servers in the background. ❚ Obey Cancel Control Messages: Sets the appliance to obey cancel control messages.
34 Intel NetStructure Cache Appliance Administrator’ s Guide Configuring FTP The FTP section lets you configure FTP protocols. The follo wing table describes the options. Authentication Server Port The port on which the locally run authentication server accepts connections.
Chapter 4 Configuring the Appliance 35 Using the Cache page The Cache page allo ws you to configure the following: ✔ Cache acti vation ✔ Object freshness ✔ V ariable object content ▼ Reaching the Cache page 1 Be sure you are in configure mode.
36 Intel NetStructure Cache Appliance Administrator’ s Guide Storage The follo wing table describes the storage options. Freshness The follo wing table describes the freshness options. Option Description Maximum HTTP/FTP object size in bytes Specifies the maximum size of HTTP or FTP objects the appliance can cache.
Chapter 4 Configuring the Appliance 37 FTP cached objects expire Specifies how long the appliance will keep FTP objects in the cache. Y ou can specify from 15 minutes to two weeks.
38 Intel NetStructure Cache Appliance Administrator’ s Guide V ariable content The follo wing table describes the variable configuration options. Option Description Do not cache Instructs the appliance to refuse to cache objects served in response to URL addresses that contain: ❚ ? ❚ ; ❚ cgi ❚ end in .
Chapter 4 Configuring the Appliance 39 Using the Security page The Security page lets you configure access to the Manager UI. Y ou can set administrator and guest IDs and passwords (guests ha ve read-only access) for the selected node. ▼ Reaching the Security page 1 Be sure you are in configure mode.
40 Intel NetStructure Cache Appliance Administrator’ s Guide ▼ Reaching the Routing page 1 Be sure you are in configure mode. If not, click the CONFIGURE tab . 2 Click the Routing page button. Setting HTTP parent caching options The appliance can participate as a member of an HTTP cache hierarchy .
Chapter 4 Configuring the Appliance 41 Setting ICP options In the ICP section you can establish ICP peers. The follo wing table describes the ICP options. Establishing ICP peers For ICP to w ork, the appliance must recognize its ICP neighbors (siblings and parents).
42 Intel NetStructure Cache Appliance Administrator’ s Guide ▼ Adding an ICP Peer 1 Click the ICP Peers link. 2 Click the Add Entry button. 3 Enter the information for the ICP peer host. If you want to clear the entire form of information, you can press the Reset button.
Chapter 4 Configuring the Appliance 43 Setting server accelerator options The Server Accelerator section allo ws you to configure the appliance as a Server Accelerator (also known as a re verse or serv er-side proxy).
44 Intel NetStructure Cache Appliance Administrator’ s Guide 2 Click the Add Entry button. 3 From the T ype field, select the type of rule you want to set ( map or reverse_map ).
Chapter 4 Configuring the Appliance 45 Configuring the host database The appliance host database stores the domain name server (DNS) entries of servers that the appliance contacts to fulfill user requests. Y ou configure the appliance host database by setting options in the Host Database Management section.
46 Intel NetStructure Cache Appliance Administrator’ s Guide Background timeout Specifies how long DNS entries can remain in the database before they are flagged as entries to refresh in the background. These entries are still fresh, so they can be refreshed after they are served, rather than before.
Chapter 4 Configuring the Appliance 47 Configuring DNS The DNS Configuration section lets you configure DNS services. The follo wing table describes the options. Using the Snapshots page The Snapshots page lets you take snapshots of the selected appliance’ s configurations or lets you restore pre viously sav ed configurations.
48 Intel NetStructure Cache Appliance Administrator’ s Guide ▼ Reaching the Snapshots page 1 Be sure you are in configure mode. If not, click the CONFIGURE tab .
49 Chapter 5 Using the Command-Line Interface This chapter describes the command-line utility that you can use to configure the system’ s network addresses and to control, configure, and monitor the Intel NetStructure Cache Appliance.
50 Intel NetStructure Cache Appliance Administrator’ s Guide Starting the command-line interface The command-line interface displays automatically on screen when you pro vide a serial interface connection to the appliance.
Chapter 5 Using the Command-Line Interface 51 These menu selections let you do the follo wing: ✔ setup —Change the system’ s network address configuration and time settings.
52 Intel NetStructure Cache Appliance Administrator’ s Guide As you navig ate through windows, you see the path of the windo w displayed in the top menu border , starting with the root menu. The follo wing steps provide an e xample of ho w to view cache performance statistics from the monitor menu.
Chapter 5 Using the Command-Line Interface 53 4 In the New Hostname field, enter the hostname that you want to assign to the appliance, and press Enter . 5 In the New Netmask field, enter the netmask address that you want to assign to the appliance system, and press Enter .
54 Intel NetStructure Cache Appliance Administrator’ s Guide Configuring time zone settings Y ou can configure the appliance for the appropriate time zone. ▼ Configuring the time zone setting 1 Select the setup menu, and press Enter . 2 Select timezone, and press Enter .
Chapter 5 Using the Command-Line Interface 55 ✔ Start the appliance cache and proxy services. ✔ Stop the appliance cache and proxy services. ✔ V ie w and maintain the version of software installed on the appliance. ✔ Clear persistent statistics.
56 Intel NetStructure Cache Appliance Administrator’ s Guide V iewing and maintaining versions of the software Y ou can have up to two versions of the appliance softw are installed on the system at the same time. From these versions, you can choose which one is current and ex ecutes in the appliance.
Chapter 5 Using the Command-Line Interface 57 4 Regardless of the type of upgrade, that is, application, patch, or OS/ application, each upgrade requires two files, which you must copy into the correct directory on the FTP server: upgrade_info <upgrade_name>.
58 Intel NetStructure Cache Appliance Administrator’ s Guide Patch upgrade After you press Ctrl-X to proceed, the CLI displays this message: Installing The Patch. Please Wait... The server transfers the application upgrade tar.gz (typically less than 10 MB).
Chapter 5 Using the Command-Line Interface 59 Deleting a version of the appliance software Y ou can delete a version of the appliance software when you need to add a ne wer version b ut you already have tw o versions installed. Note Y ou cannot delete the currently running version of the appliance software.
60 Intel NetStructure Cache Appliance Administrator’ s Guide 5 Press CTRL-X to clear the statistics and return to the pre vious screen. Choosing to clear the statistics causes a confirmation message to appear . 6 Select start , and press Enter . Doing so resumes the caching functions in the appliance.
Chapter 5 Using the Command-Line Interface 61 2 Select passwd , and press Enter . Doing so causes a prompt to appear requesting you to type and confirm the ne w administrator password. 3 Enter and confirm the ne w password. 4 Press CTRL-X to sav e your changes and return to the previous screen.
62 Intel NetStructure Cache Appliance Administrator’ s Guide ✔ Configure routing options. ✔ Configure the Adapti ve Redirection Module (ARM) for transparent proxy caching. ✔ Configure the host database options. ✔ Configure logging options.
Chapter 5 Using the Command-Line Interface 63 address you want to use in this field and press CTRL-X to sa ve your changes and return to the pre vious screen. ✔ T o see whether the appliance is in rev erse or forward proxy mode, select view-mode , and press Enter .
64 Intel NetStructure Cache Appliance Administrator’ s Guide User-Agent: identifies the agent making the request, usually a bro wser Cookie: identifies the user that made the request ✔ T o add HTTP headers, select add , and press Enter .
Chapter 5 Using the Command-Line Interface 65 ✔ T o Disable the appliance from caching and serving news articles select disable , and press Enter . ✔ T o allow NNTP serv er feeds, select the first feeds in the menu and press Enter . ✔ T o inhibit NNTP server feeds select the second feeds in the menu and press Enter .
66 Intel NetStructure Cache Appliance Administrator’ s Guide The follo wing table describes the tags you can use in a rule: T ag Description hostname Choose one of the following: ❚ host name ❚ host name:port ❚ IP address ❚ IP address:port ❚ .
Chapter 5 Using the Command-Line Interface 67 priority (continued) ❚ feed The appliance will receive news feeds for the specified groups as the parent NNTP server receives news feeds. The appliance will not cache articles on demand, since it will have them.
68 Intel NetStructure Cache Appliance Administrator’ s Guide Examples The follo wing rule tells the appliance to block all requests from rec.* groups with the exception of rec.
Chapter 5 Using the Command-Line Interface 69 ▼ V ie wing NNTP server rules 1 Select the config menu, and press Enter . 2 Select protocols , and press Enter . 3 Select nntp , and press Enter . 4 Select servers , and press Enter . 5 Select view , and press Enter .
70 Intel NetStructure Cache Appliance Administrator’ s Guide The follo wing table lists the access directiv e options: The follo wing is an example of custom access: ▼ Deleting NNTP access rules 1 Select the config menu, and press Enter . 2 Select protocols , and press Enter .
Chapter 5 Using the Command-Line Interface 71 Configuring Secure Socket Layer (SSL) port Y ou can view and specify the ports to which SSL is restricted. ▼ V ie wing SSL ports 1 Select the config menu, and press Enter . 2 Select protocols , and press Enter .
72 Intel NetStructure Cache Appliance Administrator’ s Guide ✔ T o set the inactivity timeout (the length of time the appliance w aits for a response from the FTP server before abandoning the user’ s request for data), select inactivity , and press Enter .
Chapter 5 Using the Command-Line Interface 73 The secondary specifiers are optional. The follo wing table lists the possible tags and their allo wed values: The follo wing table lists the possible action tags and their allowed v alues: Examples The follo wing rule tells the appliance to deny FTP document requests to the IP address 112.
74 Intel NetStructure Cache Appliance Administrator’ s Guide The follo wing rule tells the appliance to k eep the client IP address header for URL addresses that contain the regular e xpression politics and whose path prefix is /viewpoint . The follo wing rule tells the appliance to strip all cookies to the requested host www.
Chapter 5 Using the Command-Line Interface 75 3 Select remap , and press Enter . 4 Select add rules , and press Enter . 5 Enter a remap rule, and press Enter . 6 Press CTRL-X to sav e your changes and return to the previous screen. Each rule must consist of three fields: type target replacement .
76 Intel NetStructure Cache Appliance Administrator’ s Guide Configuring the cache Y ou can configure cache storage options to do the following: ✔ Enable caching of objects for dif ferent protocols. ✔ Set disk storage options. ✔ Set freshness properties.
Chapter 5 Using the Command-Line Interface 77 Setting disk storage options Y ou can configure the cache to store only objects below a certain size and to store a limited number of alternates. ▼ Setting disk storage options 1 Select the config menu, and press Enter .
78 Intel NetStructure Cache Appliance Administrator’ s Guide The follo wing table shows the options: Option Description Options to V erify freshness Choosing this option lets you configure how the appliance asks the original content server to verify the freshness of objects (revalidate them) before serving them.
Chapter 5 Using the Command-Line Interface 79 Configuring caching rules The appliance uses caching rules to determine ho w a particular group of URL addresses should be cached.
80 Intel NetStructure Cache Appliance Administrator’ s Guide 3 Select rules , and press Enter . 4 Select add rules , and press Enter . 5 Enter a caching rule, and press Enter .
Chapter 5 Using the Command-Line Interface 81 The follo wing table lists the possible action tags and their allowed v alues: Examples The follo wing rule tells the appliance to nev er cache FTP documents requested from the IP address 112.
82 Intel NetStructure Cache Appliance Administrator’ s Guide ▼ V ie wing cache rules 1 Select the config menu, and press Enter . 2 Select cache , and press Enter . 3 Select rules , and press Enter . 4 Select view rules , and press Enter . Doing so displays the file containing the cache rules.
Chapter 5 Using the Command-Line Interface 83 3 Select serve r , and press Enter . 4 Select delete rules , and press Enter . Doing so displays a list of current rules. If no rules exist, a message displays at the bottom of the screen indicating such. 5 Use the arro w keys to position the cursor o ver the rule you want to delete, and press Enter .
84 Intel NetStructure Cache Appliance Administrator’ s Guide ▼ Deleting Manager Allo w rules 1 Select the config menu, and press Enter . 2 Select security , and press Enter . 3 Select mgmt , and press Enter . 4 Select delete rules , and press Enter .
Chapter 5 Using the Command-Line Interface 85 ▼ Adding ICP rules 1 Select the config menu, and press Enter . 2 Select routing , and press Enter . 3 Select icp , and press Enter . 4 Select rules , and press Enter . 5 Select add rules , and press Enter .
86 Intel NetStructure Cache Appliance Administrator’ s Guide Example The follo wing example configuration is for three nodes: the local host, one parent, and one sibling: ▼ Deleting ICP rules 1 Select the config menu, and press Enter . 2 Select routing , and press Enter .
Chapter 5 Using the Command-Line Interface 87 ▼ V ie wing ICP rules 1 Select the config menu, and press Enter . 2 Select routing , and press Enter . 3 Select icp , and press Enter . 4 Select rules , and press Enter . 5 Select view rules , and press Enter .
88 Intel NetStructure Cache Appliance Administrator’ s Guide Enabling and disabling multicast in ICP Y ou can enable or disable multicast in ICP . ▼ Enabling multicast in ICP 1 Select the config menu, and press Enter . 2 Select routing , and press Enter .
Chapter 5 Using the Command-Line Interface 89 ▼ Setting the ICP query timeout number 1 Select the config menu, and press Enter . 2 Select routing , and press Enter . 3 Select icp , and press Enter . 4 Select timeout , and press Enter . Doing so causes a field to appear that has the current timeout v alue in seconds displayed.
90 Intel NetStructure Cache Appliance Administrator’ s Guide 7 Press CTRL-X to sav e your rule and return to the previous screen. Each rule must hav e the following format: The follo wing table lists the primary destinations and their allowed v alues: The secondary specifiers are optional.
Chapter 5 Using the Command-Line Interface 91 Examples The follo wing rule sets up a parent proxy hierarchy consisting of the appliance (which is the child) and two parents, p1 and p2 . All get requests, if they cannot be serv ed by the appliance, are routed to the first parent server , p1.
92 Intel NetStructure Cache Appliance Administrator’ s Guide ▼ V ie wing parent proxy caching rules 1 Select the config menu, and press Enter . 2 Select routing , and press Enter . 3 Select parent , and press Enter . 4 Select delete , and press Enter .
Chapter 5 Using the Command-Line Interface 93 bottom field and press Enter . Finally , press CTRL-X to save your changes and return to the pre vious screen. ✔ T o disable multicast communication, select disable multicast , and press Enter . ✔ T o enable HTTP redirection, select enable HTTP , and press Enter .
94 Intel NetStructure Cache Appliance Administrator’ s Guide Configuring ARM bypass rules The appliance uses ARM bypass rules to determine whether to bypass incoming client requests or to attempt to serve them transparently . Y ou can add, delete, and view ARM bypass rules.
Chapter 5 Using the Command-Line Interface 95 The bypass rules hav e the following format: Examples The follo wing e xamples sho w source, destination, and source/destination bypass rules: ▼ Deleting ARM bypass rules 1 Select the config menu, and press Enter .
96 Intel NetStructure Cache Appliance Administrator’ s Guide 3 Select bypass , and press Enter . 4 Select rules , and press Enter . 5 Select view rules , and press Enter .
Chapter 5 Using the Command-Line Interface 97 5 Press CTRL-X to sav e your changes and return to the previous screen. The follo wing table describes the options: Option Description Lookup Timeout Specifies the timeout period in seconds for the IP address lookup operation in the host database.
98 Intel NetStructure Cache Appliance Administrator’ s Guide ▼ V ie wing host database options 1 Select the config menu, and press Enter . 2 Select hostdb , and press Enter . 3 Select view , and press Enter . Configuring logging options Y ou can configure the logging options used in the appliance.
Chapter 5 Using the Command-Line Interface 99 4 Supply a v alue for each field you want to change, and press Enter after filling in each field. 5 Press CTRL-X to sav e your changes and return to the previous screen. ▼ V ie wing logging options 1 Select the config menu, and press Enter .
100 Intel NetStructure Cache Appliance Administrator’ s Guide V iewing Protocol statistics Protocol statistics report the appliance system’ s use of the HTTP , NNTP , FTP , and ICP protocols. ▼ V ie wing protocol statistics 1 Select the monitor menu, and press Enter .
Chapter 5 Using the Command-Line Interface 101 The follo wing table describes the statistics for the HTTP protocol. Statistics exist for both the client and serv er . Errors ❚ Connect Failures—The percentage of connect errors and their average transaction times.
102 Intel NetStructure Cache Appliance Administrator’ s Guide The follo wing table describes the protocol for the NNTP protocol. Statistics and descriptions exist for Client, Serv er, and Operations. T otal Connections The total number of HTTP server connections since installation.
Chapter 5 Using the Command-Line Interface 103 The follo wing table describes the statistics for the FTP protocol: The follo wing table describes the statistics for the ICP protocol. Statistics exist for queries originating from the node and for queries originating from ICP peers.
104 Intel NetStructure Cache Appliance Administrator’ s Guide V iewing Cache statistics Cache statistics report information about the cache size, bytes used, object look- up operations, object reads, object writes, update operations, and remov e operations.
Chapter 5 Using the Command-Line Interface 105 V iewing Other statistics Other statistics report information about host database lookups, DNS lookups, cluster connections, and logging. ▼ V ie wing host database statistics 1 Select the monitor menu, and press Enter .
106 Intel NetStructure Cache Appliance Administrator’ s Guide ▼ V ie wing DNS statistics 1 Select the monitor menu, and press Enter . 2 Select other , and press Enter . 3 Select dns , and press Enter . Doing so causes the statistics to display on the screen.
Chapter 5 Using the Command-Line Interface 107 ▼ V ie wing logging statistics 1 Select the monitor menu, and press Enter . 2 Select other , and press Enter . 3 Select logging , and press Enter . Doing so causes the statistics to display on the screen.
108 Intel NetStructure Cache Appliance Administrator’ s Guide Using the save menu The sa ve menu lets you sa ve the current appliance configuration to a flopp y disk. ▼ Saving the current configuration to a flopp y disk 1 Select the sa ve menu, and press Enter .
109 Chapter 6 T roubleshooting Pr oblems When the system doesn’t seem to be operating correctly , you can use the information in this chapter to help you find a solution. If the information in this chapter doesn’t solv e your problem, refer to the Intel NetStructur e Caching Appliance Pr oduct Support booklet that came with your system.
110 Intel NetStructure Cache Appliance Administrator’ s Guide Rebooting your system Rebooting the Intel NetStructure Cache Appliance causes the underlying operating system to reboot. Rebooting the appliance is not the same as starting and stopping the caching software on your system.
Chapter 6 T roubleshooting Problems 111 Upgrading software Periodically the caching application that runs on the Intel NetStructure Cache Appliance might need upgrading or might need to hav e a patch applied. In this case, visit Intel’ s ISP web site at http://www .
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113 A ppendix A Caching Solutions and P erf or mance This appendix is an ov ervie w of the W eb caching capabilities and performance of the Intel NetStructure Cache Appliance.
114 Intel NetStructure Cache Appliance Administrator’ s Guide W eb proxy caching The Intel NetStructure Cache Appliance is a high-performance caching proxy server . It is designed to efficiently handle multiple client connections simultaneously and supports HTTP , FTP , NNTP , ICP , and WCCP 2.
Appendix A Caching Solutions and Performance 115 Step 4 If the data in the cache is stale, the appliance connects to the origin server and asks if the document is still fresh. If the document is still fresh, the appliance sends the cached copy to the user immediately .
116 Intel NetStructure Cache Appliance Administrator’ s Guide HTTP W eb documents support optional author-specified e xpiration dates. The appliance adheres to these expiration dates; otherwise it picks an e xpiration date based on ho w frequently the document is changing and on administrator-chosen freshness guidelines.
Appendix A Caching Solutions and Performance 117 For e xample, if a document was last modified 32 days ago and was sent to the appliance two days ago, the document is considered fresh in cache for three days after it was sent. (This assumes a factor of 10%.
118 Intel NetStructure Cache Appliance Administrator’ s Guide ✔ The min-fresh field, sent by clients, is an acceptable fr eshness tolerance . The client wants the object to be at least this fresh. If a cached document does not remain fresh at least this long in the future, it is re validated.
Appendix A Caching Solutions and Performance 119 ✔ Ev aluate freshness as follows: 1 Use the Expires header test, if applicable, otherwise go to step 2. If the object is stale, re validate. If it is fresh, check the Cache-Control headers. 2 Use the Last-Modified / Date header test, if applicable, otherwise go to step 3.
120 Intel NetStructure Cache Appliance Administrator’ s Guide The follo wing table lists the HTTP caching directi ves that the appliance follo ws. T ransparent proxy caching In nontransparent proxy caching, client bro wsers must be configured to send W eb requests to the Intel NetStructure Cache Appliance proxy .
Appendix A Caching Solutions and Performance 121 ✔ Information on ho w the ARM changes packet addresses. See ARM r edirection‚ on pa ge 125 . ✔ A description of the appliance’ s adapti ve bypass scheme. See Appliance adaptive bypass‚ on page 126 .
122 Intel NetStructure Cache Appliance Administrator’ s Guide appliance, or routers or switches feeding it, is often deployed at a major artery or aggregation pipe to the Internet. The follo wing sections provide more details about the Intel NetStructure Cache Appliance’ s transparency routing solutions.
Appendix A Caching Solutions and Performance 123 Using a WCCP-enabled router for transparency A WCCP 2.0-enabled router can send all port 80 (HTTP) traffic to the Intel NetStructure Cache Appliance, as sho wn in F igur e 4 .
124 Intel NetStructure Cache Appliance Administrator’ s Guide ✔ The appliance handles node failure in WCCP cache farms. If one node goes do wn, its load is redistributed among the remaining nodes. ✔ In WCCP , you can use multiple routers. T raffic flo wing through multiple routers can share the same pool of caches.
Appendix A Caching Solutions and Performance 125 F igur e 5 illustrates policy-based routing for HTTP objects. This routing scheme has the follo wing characteristics: ✔ All client Internet traf fic is sent to a router that feeds the appliance.
126 Intel NetStructure Cache Appliance Administrator’ s Guide ✔ NNTP packet destination IPs are readdressed with the IP address of the appliance. If the appliance uses a port other than 119 for NNTP , the destination NNTP port is readdressed as well.
Appendix A Caching Solutions and Performance 127 Static and dynamic (adaptive) bypass Bypass rules can be either static or adapti ve. Adaptive bypass rules are dynamically generated if you configure the appliance to bypass in the case of non-HTTP port 80 traf fic or HTTP errors.
128 Intel NetStructure Cache Appliance Administrator’ s Guide Server acceleration In W eb proxy caching, the Intel NetStructure Cache Appliance handles arbitrary W eb requests to distant W eb servers on behalf of a set of users. Server acceleration (also kno wn as rev erse proxy caching or virtual W eb hosting) is slightly dif ferent.
Appendix A Caching Solutions and Performance 129 Advantages of server acceleration Server acceleration adv antages are similar to W eb proxy caching: ✔ The appliance is optimized for speed and multiple user connections and can be deployed close to users.
130 Intel NetStructure Cache Appliance Administrator’ s Guide Whereas the corresponding proxy request would look like this: The appliance can construct a proxy request from a server request by using the server information in the host header . Y ou might hav e noticed a small problem.
Appendix A Caching Solutions and Performance 131 This map rule specifies the path /jazz for jazz.flute.org on the server big.server.net . Generally , you use reverse proxy mode to support more than one origin serv er .
132 Intel NetStructure Cache Appliance Administrator’ s Guide Understanding server acceleration mapping rules Re write rules each consist of three space-delimited fields: type , target , and replacement . ✔ Type indicates the type of rule. ✔ Target specifies the URL from which the request originates.
Appendix A Caching Solutions and Performance 133 In a typical Server Accelerator configuration, there should be a reverse-map rule for e very map rule, with the origin URL and replacement URL of the map rule re versed. Examples of rules and translations The follo wing examples illustrate se veral important cases of rewrite rules.
134 Intel NetStructure Cache Appliance Administrator’ s Guide In these examples, the second rule is ne ver applied because all URL addresses that match the second rule also match the first rule. The first rule tak es precedence because it appears earlier in the remap.
Appendix A Caching Solutions and Performance 135 Understanding cache hierarchies Cache hierarchies consist of le vels of caches that communicate with each other . Hierarchical caching can gi ve you information about the local access requirements of your users; this information might not appear in a large central cache.
136 Intel NetStructure Cache Appliance Administrator’ s Guide For information on ho w to enable parent caching from the Manager UI, see the parent caching section on the Configure: Routing page (see Setting HTTP par ent caching options‚ on page 40 ).
Appendix A Caching Solutions and Performance 137 How an ICP hit can be a miss If the appliance recei v es a hit message from an ICP peer, then it sends the HTTP request to that peer . It might turn out to be an actual miss, because the original HTTP request contains header information that is not communicated by the ICP query .
138 Intel NetStructure Cache Appliance Administrator’ s Guide News article caching The Intel NetStructure Cache Appliance can function as a ne ws server or a caching ne ws server . News, also kno wn as USENET and discussions , is a system of online discussion groups.
Appendix A Caching Solutions and Performance 139 The appliance as a news server As a ne ws server , the Intel NetStructure Cache Appliance does the following: ✔ Maintains lists of supported ne ws gr.
140 Intel NetStructure Cache Appliance Administrator’ s Guide Some of the possible parent configurations that the appliance supports are as listed belo w: Sev eral news servers supplying the same gr oups: Se veral ne ws servers can be configured to redundantly serv e the same groups, providing enhanced reliability .
Appendix A Caching Solutions and Performance 141 T wo types of clusters are supported: soft clusters and management-only clusters. A soft cluster consists of multiple appliances that use an external clustering de vice such as an L4 Switch or router to handle load balancing and routing responsibilities.
142 Intel NetStructure Cache Appliance Administrator’ s Guide Pull the articles f or specified groups: For all groups designated as pull , the appliance will retrie ve the articles automatically and periodically . Pulling groups is useful when you do not want to or cannot set up a full or partial feed.
Appendix A Caching Solutions and Performance 143 Obeying NNTP control messages By default, the Intel NetStructure Cache Appliance periodically checks the parent server for ne w groups, cancelled articles, and new articles for nonfeed ne ws groups.
144 Intel NetStructure Cache Appliance Administrator’ s Guide Fine-grained parallelism The appliance uses a highly parallel application that can manage hundreds of thousands of concurrent acti vities by combining kernel multithreading with an internal scheduling system called Nanothreading.
Appendix A Caching Solutions and Performance 145 Advanced pr otocol features The appliance supports ✔ Performance features of the emerging HTTP 1.1 protocol, such as persistent connections, request pipelining, and cache-control features.
146 Intel NetStructure Cache Appliance Administrator’ s Guide F igure 10 The Monitor Dashboar d The appliance also supports email notification for alarms.
Appendix A Caching Solutions and Performance 147 Load shedding Overload conditions, such as netw ork outages, misconfigured routers, or security attacks, can slo w down the Intel NetStructure Cache Appliance’ s response time.
148 Intel NetStructure Cache Appliance Administrator’ s Guide Centralized administration The Intel NetStructure Cache Appliance incorporates many nati ve command and control features for carrier-class system management and administration.
Appendix A Caching Solutions and Performance 149 enable SNMP access to either one or both of these MIBS on your Intel NetStructure Cache Appliance. See Enabling SNMP agents‚ on pa ge 29 . If a de vice fails, it can send a warning message or an SNMP trap to the SNMP monitoring station.
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151 A ppendix B Er r or Messa ges This appendix contains the follo wing sections: ◆ HTML messages sent to clients‚ on pa ge 152 describes the HTML error messages that the Intel NetStructure Cache .
152 Intel NetStructure Cache Appliance Administrator’ s Guide HTML messages sent to clients The appliance returns detailed error messages to bro wser clients when there are problems with the HTTP transactions requested by the bro wser . These response messages correspond to standard HTTP response codes, but pro vide more information.
Appendix B Error Messages 153 Host Header Required 400 An attempt was made to transparently proxy your request, but this attempt failed because your browser did not send an HTTP “Host” header. Please manually configure your browser to use http:// < proxy_name >:< proxy port > as an HTTP proxy .
154 Intel NetStructure Cache Appliance Administrator’ s Guide Standard HTTP response messages The follo wing standard HTTP response messages are provided for your information. For a more complete list and descriptions, see the Hyperte xt T ransfer Protocol — HTTP/1.
Appendix B Error Messages 155 400 Bad Request 401 Unauthorized; retry 403 Forbidden 404 Not Found 405 Method Not Allowed 406 Not acceptable 408 Request Timeout 500 Internal server error 501 Not Implem.
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157 Glossar y Alternates Dif ferent versions of the same web object. Some web servers answer requests to the same URL with a v ariety of objects. The content of these objects can v ary widely , depend.
158 Intel NetStructure Cache Appliance Administrator’ s Guide Cluster A group of the Intel NetStructure Cache Appliance nodes that are configured to act as a single large virtual cache. F or information on the supported cluster schemes, see Management-only clustering and Soft Cluster .
Glossary 159 ISP Internet Service Provider . An organization that provides access to the Internet. JavaScript A network-oriented programming language specifically designed for writing programs that can be safely do wnloaded to your computer through the Internet.
160 Intel NetStructure Cache Appliance Administrator’ s Guide Parent cache A cache higher up in a Cache hier arc hy , to which the Intel NetStructure Cache Appliance can send requests. POP 1. Point of Presence. Usually a city or location to which a network can be connected, often with dial up phone lines.
Glossary 161 V irtual IP failover An option av ailable to clustered Intel NetStructure Cache Appliances, where the appliance maintains a pool of virtual IP addresses that it assigns to the nodes of a cluster . If a node fails, the remaining nodes mask the fault and take o ver the failed node’ s virtual interface.
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163 Inde x A adaptive bypass 126 Adaptive Redirection Module about 145 what it does 121 alternates 119 ARM about 145 WCCP and 124 what it does 121 B bypass options 127 bypass rules dynamic 127 static .
164 Intel NetStructure Cache Appliance Administrator’ s Guide N news server features 138 NNTP access control 32 caching 139 configuring 31 dynamic subscription 142 feed groups 32 object freshness 14.
Un punto importante, dopo l’acquisto del dispositivo (o anche prima di acquisto) è quello di leggere il manuale. Dobbiamo farlo per diversi motivi semplici:
Se non hai ancora comprato il Intel 1520 è un buon momento per familiarizzare con i dati di base del prodotto. Prime consultare le pagine iniziali del manuale d’uso, che si trova al di sopra. Dovresti trovare lì i dati tecnici più importanti del Intel 1520 - in questo modo è possibile verificare se l’apparecchio soddisfa le tue esigenze. Esplorando le pagine segenti del manuali d’uso Intel 1520 imparerai tutte le caratteristiche del prodotto e le informazioni sul suo funzionamento. Le informazioni sul Intel 1520 ti aiuteranno sicuramente a prendere una decisione relativa all’acquisto.
In una situazione in cui hai già il Intel 1520, ma non hai ancora letto il manuale d’uso, dovresti farlo per le ragioni sopra descritte. Saprai quindi se hai correttamente usato le funzioni disponibili, e se hai commesso errori che possono ridurre la durata di vita del Intel 1520.
Tuttavia, uno dei ruoli più importanti per l’utente svolti dal manuale d’uso è quello di aiutare a risolvere i problemi con il Intel 1520. Quasi sempre, ci troverai Troubleshooting, cioè i guasti più frequenti e malfunzionamenti del dispositivo Intel 1520 insieme con le istruzioni su come risolverli. Anche se non si riesci a risolvere il problema, il manuale d’uso ti mostrerà il percorso di ulteriori procedimenti – il contatto con il centro servizio clienti o il servizio più vicino.
