Intel 1520 manuale d’uso

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, transcribed, stored in a retrie val system, or translated into an y language or computer language, in any form or by any means, electronic, mechanical,[...]

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? ............................... 2 Why use this caching[...]

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 ............................................................................. 22 Using the MRTG 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 ........................................... 50 Navigating the c[...]

vi Intel NetStructure Cache Appliance Administrator’ s Guide vi Intel NetStructure Cache Appliance Administrator’ s Guide Using the monitor menu ......................................................................... 99 Viewing Node statistics .................................................................... 99 Viewing Protocol statistics [...]

Contents vii Understanding cache hierarchies ......................................................... 135 HTTP cache hierarchies................................................................. 135 ICP cache hierarchies .................................................................... 136 NNTP 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 ........................................................................ 22 Reaching the Other page .[...]

Contents ix Preparing a cache disk ........................................................................... 61 Setting general controls .......................................................................... 62 Configuring HHTP options ...................................................................... 63 Configuring NNTP 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 .................................................................... 95 Configuring load-shedding optio[...]

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. ◆ Chapter [...]

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. Consequently , the information in the manual was written with the assumption that the reader has experience in W eb server admin[...]

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. When placed [...]

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. Unfortunately , global data networking has become difficult for professionals as they struggle with o verloaded servers trying to keep pace with society’ s [...]

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. This server accelerator feature is also called r everse pr oxy .[...]

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. The appliance processes multiple outstanding requests simultaneously and ef ficiently ,[...]

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). The first, MIB-2 is a well kno wn standard MIB. The second, the proprietary Intel NetStructure Cache Appliance MIB provides more specific node and c[...]

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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 command-line interface‚ on page 15 ◆ V erifying that caching works‚ on pag e 15 ◆ Changing passwor ds‚ on page 15[...]

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. ✔ Connecting a T erminal Emulator or Concentrat[...]

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. —setup Initial I[...]

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 . Here is a partial list: –United States Eastern United States Central United States Mountain United States Pacific 12 Use the arro [...]

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 cursor on commit as follo ws: setup Initial Intel Cache Setup install Install Intel Cache –commit Commit Setup Changes 18 Pressing the Enter ke y star[...]

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 . Y ou can access any node in the cluster through the same Manager UI. ▼ A[...]

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 . ✔ In Configure mode, vie w and modify the appliance’ s configuration options[...]

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. With the e xception of t[...]

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. Accessing the command-line interface Y ou can access the command-line interface using one of t[...]

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 . T o change the password for the telnet or serial connection, see Changing the [...]

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. This chapter contains the follo wing sections: ◆ Accessing monitor pages‚ on pa ge 18 ◆ Using the Dashboar d page‚ on page 18 ◆ Using the Node page‚ [...]

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. By default, the Manager UI sta[...]

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. ✔ See the number (cumulati ve to date) of objects[...]

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. Changing the selected node As mentioned earlier , information on pages accessed in monitor mode exists for the selec[...]

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. If not, click the MONITOR tab . 2 Cli[...]

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. Using the Other page The Other page reports statistics for the v arious appliance f[...]

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. This chapter contains the follo wing sections: ◆ Accessing configur e pages‚ on page 24 ◆ Using the Server Basi[...]

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. Note Some performance displ[...]

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. That is, you can turn caching[...]

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. Setting virtual IP addressing options The V irtual IP Addressing section lets you [...]

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. ▼ Modifying the V irtual IP address list 1 On the Server B[...]

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. Load shedding is temporary; when hit-transaction times return to acceptable le vels, the appliance re ve[...]

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 interface to configure the appliance to cache articles from particular NNTP servers and ne ws groups as well as to set access restrictions and authenti[...]

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. Click the Restart button on the Ser[...]

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. When the appliance gets a cancel control message, it deletes the corresponding article fro[...]

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. If the authentication server is remote, the appliance connects to it on [...]

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. If not, click the CONFIGURE tab . 2 Click the Cache page button. The follo wing sections descri[...]

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. Use a 0 (zero) to indicate no l[...]

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. Internet Explorer requests force a check with the origin server Configures the appliance to treat Microsoft Internet Explorer requests more conservatively , providing f[...]

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 . asp Enable Alternates Instructs the[...]

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. If not, click the CONFIGURE tab . 2 Click t[...]

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 . Y ou can point your appliance at a parent net[...]

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). Option Description ICP Mode Enables or disables ICP mode: ❚ Only Receive Queries[...]

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. 4 Click the Add button to sa ve your changes. Field Description Hostname T[...]

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). Y ou can enable or disable this function as well as control ho w the appliance routes document requests to the slo wer traditional[...]

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 ). 4 In the T arget field, enter the origin or fr om URL for the rule. Y ou can enter up to four components; for example, <scheme>://<host>:<port>/ <[...]

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. The follo wing table describes the opt[...]

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. Y ou can choose from the following: ❚ 3 hour[...]

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. A configurati[...]

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 . 2 Click the Snapshots page button. The follo wing table describes the options. Note Once you create a snapshot for the appliance, you should remov e the floppy diskette from the dri [...]

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. This chapter contains the follo wing sections: ◆ Starting the command-line interface‚ on page 50 ◆ Naviga[...]

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. F or information on how to mak e a serial connection to the appliance, see the Intel NetStructur e Cache Appliance Quick Star[...]

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. See Using the setup menu‚ on page 52 for more information. ✔ main —Start or stop the cache and proxy services, check version information, clear statistics, and ins[...]

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. 1 From the initial menu, use the do wn arrow k e[...]

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 . 6 Press CTRL-X to sav e your changes and return to the previous menu. Cha[...]

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 . Doing so displays a list of av ailable time zone settings. 3 Use the up [...]

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. ✔ Reboot the system. ✔ Halt the system. ✔ Change Administrator password for telnet and ser[...]

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. Installing a new version of the softw are auto[...]

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>.tar.gz ▼ Starting the upgrade from the appliance side 1 Start the command line int[...]

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). When the transfer is complete, the CLI displays this message: Ftp Fetching Successful The[...]

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. T o delete that software, you must first[...]

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. Rebooting the System Y ou can reboot the sys[...]

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. Note Changing the password v alue using CLI changes [...]

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. Setting general controls Y ou can stop, start, or restart caching on the local appliance or clus[...]

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 . A message displays at the bottom of the screen that indicates re verse or forward[...]

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 . Y ou can add the follo wing headers: From: identifies the user’ s email address Referer: identifies th[...]

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 . ✔ T o allow NNTP acces[...]

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 ❚ .block—Use .block to block access to specific news groups. group-wildmat This tag must be a com[...]

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. ❚ push The appliance can both receive news feeds and cache articles on demand. ❚ pull [...]

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.soccer : The follo wing rule is an example of setting the port associated with the hostname: The follo wing rule is an example of associating an interf ace and priority wit[...]

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 . Doing so displays the file containing the NNTP server rules. Configuring NNTP acc[...]

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 . 3 Select nntp , and press Enter . 4 Select access , 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 . 3 Select ssl , and press Enter . 4 Select view , and press Enter . Doing so displays the [...]

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 . Doing so causes a field to appear with the current setting displayed. Supply the ne w [...]

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 112.12.12.12. Se[...]

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.intel.com . The fol[...]

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 . The follo wing table describes the proper format fo[...]

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. ✔ Set caching rules. Enabling caching for different protocols Y ou can configure th[...]

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 . 2 Select cache , and press Enter . 3 Select storage , and press Enter . Doing s[...]

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. Select from one of the following o[...]

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. Y ou can add, delete, and view caching rules. Caching rules can specify: ✔ Whether to cache objects ✔ Ho w long to keep (pin) particular objects in the cache ✔ Ho w lo[...]

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 . 6 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 supported primary destinatio[...]

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 112.12.12.12. The follo wing rule tells the appliance to keep in the cache for 12 hours documents whose URL addresse[...]

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. Configuring security options Y ou can control clie[...]

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 . 6[...]

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 . Doing so displays a list of the current rules. If no rules exist, a message displays at the bo[...]

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 . 6 Add an ICP rule, and press Enter . 7 Press CTRL-X to sav e your rule and return to the previ[...]

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 . 3 Select icp , and press Enter . 4 Select rules , and press Enter . 5 S[...]

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 . Doing so causes the file containing the ICP rules to appear . V iewing current ICP settin[...]

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 . 3 Select icp , and press Enter . 4 Select enable-multicast , and press Enter . ▼ Disabl[...]

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. 5 Supply the ne w [...]

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. The follo wing table lists the possible tags and their a[...]

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.x.com . If they are not in the first parent serv er , the[...]

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 . 5 Select view rules , and press Enter . Doing so lists the file containing the parent proxy[...]

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 . ✔ T o disable HTTP redirection, [...]

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. ▼ Adding ARM bypass rules 1 Select the config menu, and press Enter . [...]

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 . 2 Select arm , and press Enter . 3 Select bypass , and press Enter . 4 Select rules , [...]

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 . Doing so displays the file containing ARM bypass rules. Configuring load-shedding options When transparent proxy caching is enabled, the appliance handles ov erload conditions[...]

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. Foreground Timeout Specifies how long DNS entries can re[...]

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. The appliance is able to keep system logs of [...]

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 . 2 Select logging , and press Enter . 3 Select view , and[...]

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 . 2 Select protocols , and press Enter . Doing so causes a list of protocols [...]

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. ❚ Other Errors—The percentage of other errors and their average transaction tim[...]

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. T ransactions In Progress The total number of HTTP server connect[...]

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. Post Bytes The number of total bytes posted through the traffic serv[...]

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. ▼ V ie wing Cache statistics 1 Select the monitor menu, and press Enter . 2 Select cache[...]

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 . 2 Select other , and press Enter . 3 Select hostdb , and press Enter . Doing so c[...]

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. The follo wing table describes the statistics. ▼ V ie wing cluster statistics 1 Selec[...]

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. The follo wing table describes the statistics. Using the expert menu The expert menu lets you in[...]

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 . Doing so causes the system to prompt you to insert a blank floppy disk. 2 Inse[...]

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. This c[...]

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. F or instructions on how to start and stop the caching software[...]

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 .intel.com/isp and go to the product page for your appliance. That page contains in[...]

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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. This chapter cov ers the following topics. ◆ W eb pr oxy caching‚ on pag e 114 ◆ T ranspar ent pr oxy caching‚ on page 120 ◆ Server acceleration‚ on pa ge 128 ◆[...]

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 2.0 protocols. Caching The idea behind W eb caching is[...]

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 . Step 5 If the object is not in the cache (a cache miss ) or the serv er indicate[...]

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. In addition, documents c[...]

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%.) So for this situation, the document is considered fresh for one more day . Because this me[...]

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. ✔ The max-stale field, sent by clients, permits [...]

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. If the object is fresh acc[...]

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 . Many sites hav e no direct contr[...]

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 . Serving requests transparently Here’ s ho w the Intel NetStructure Cache Appliance transpa[...]

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. Using a layer 4-aware switch to filter t[...]

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 . After the WCCP router sends port 80 traf fic, the ARM readdresses port 80 to the appliance proxy port (by default, port 808[...]

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. In F igur e 4 , appliance[...]

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. ✔ The router sends port 80 (HTTP) traf fic to the appliance and sends the remaining traf fic to the[...]

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. Adaptive interception bypass The Intel NetStructure Cache Appliance contains an adapti ve learn[...]

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. Static and dynamic rules Static and dynamic rules look exactly the s[...]

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. In server a[...]

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. ✔ Serving cached documents sav es network bandwidth. Server acceleration of fers the follow[...]

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. The correct proxy request must contain the host name of the ori[...]

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 . In this case, all of the advertised host names resolv e to the IP address or virtual IP address of the appliance (see F igur e 6 )[...]

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. ✔ Replacement specifies the URL the a[...]

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. Example 1 This ma[...]

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.config file. Example 4 A mapping with a path prefix specified in the target[...]

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. The Intel NetStructure 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 ). F or information on how to enable parent failo ver using the command-line interface, see Contr[...]

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 . For example, the hit[...]

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. NNTP is the protocol used to retrie ve and distrib ute these 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 groups ✔ Accepts ne ws feeds for each supported news group ✔ Serves requested articles to users ✔ Accepts and numbers user postings to the support[...]

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 . The appliance provides the f[...]

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. A management-only cluster also consists of mul[...]

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. Dynamically subscribe to specified groups:[...]

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. If you hav e enabled these periodic checks in the Configure: Protocols page, you do not need to con?[...]

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. Raw-disk object store The appliance stores all cached do[...]

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. ✔ A rich set of commands to optimize the performance of NNTP bro wsing, including support for RFC 977, such [...]

146 Intel NetStructure Cache Appliance Administrator’ s Guide F igure 10 The Monitor Dashboar d The appliance also supports email notification for alarms. Y ou set the email address to which alarms are sent from the command-line interface. Virtual IP failover The virtual IP failo ver option is a vailable to clustered Intel NetStructure Cache App[...]

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. In transparent configurations, the appliance can use its ARM bypass functionality to forward o verload requests directly[...]

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. The follo wing list provides an o vervie w of these features: Single system image The appliance maintains a s[...]

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. All SNMP agents require you to configure the trap destination[...]

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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 Appliance sends to bro wser clients (not to be confused with standard HTTP response codes) ◆ Standar d HTTP response messa ges‚ on page 154 descri[...]

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. A list of th[...]

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 . Please refer to your browser ’s docu[...]

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/1.1 Specification. Proxy Authentication Required 407 Please login with username a[...]

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 Implemented 502 Bad Gateway 504 Gateway Timeout Message Description[...]

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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 , depending on whether a server deli vers content for dif ferent languages, targets dif ferent browsers with dif ferent presentation styles, or deliv ers v ar[...]

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 . Configure mode One of two modes in the Intel NetStructur e C[...]

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. L4 switch An ethernet switch that can control network traf fic flo w using Lev el 4 [...]

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. 2. Post Of fice Protocol. The basic prot[...]

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. WCCP W eb Cache Control Protocol.[...]

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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 127 C cache affinity 122 Cache-Control headers 117 child cache 135 clustering management-only 141 Configuring HTTP 30 Configuring Protocols 30 Configu[...]

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 141 push groups 32 O object store 144 online help 15 origin server 114 P parent cache 135 configuring HTTP 40 HTTP 135 parent failover 135 performance 1[...]