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Advanced Internet and Web Systems. C. Edward Chow. Outline of the Talk. Syllabus Introduction to WWW Systems Survey of Web Cluster Systems Survey of Caching Techniques Server Selection and Load Balancing. Introduction to WWW Systems. Web Server Hosting web pages. Retrieving web pages

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Presentation Transcript

Outline of the talk l.jpg
Outline of the Talk

  • Syllabus

  • Introduction to WWW Systems

  • Survey of Web Cluster Systems

  • Survey of Caching Techniques

  • Server Selection and Load Balancing

chow


Introduction to www systems l.jpg
Introduction to WWW Systems

Web Server

Hosting web pages

Retrieving

web pages

using HTTP

protocol

Web Authoring System

create web pages

Internet

Web Client

Browser

Publish

web pages

Scanner

Video capture

Sound card

Web page: document written in HTML

chow


What is unique in www l.jpg
What is Unique in WWW?

  • Hyperlink: Use Hypertext Markup Language HTML to describe the document in ASCII text (extended to iso-8859-1)

  • Naming scheme: Name object in the web with Universal Resource Locator (URL) with syntax:protocol://domain_name/<uri or path name>

  • HTTP: HyperText Transfer Protocola simple request-response protocol for transferring HTML documents

    • ASCII text based (not binary, therefore easy to debug)

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Web authoring system l.jpg
Web Authoring System

  • Text Editor: type in HTML <tag> and content

  • HTML Editor: like normal word processor, user did not have know a lot about HTML syntax, e.g.,

    • Netscape Page Composer, MS Front Page

  • Front Page takes another step by providing templates and hyperlink management functions

  • Dreamweaver allows site management (upload/download); editor understands PHP, XSLT, XML, CSS, JavaScript syntax.

  • Most desktop publishing software and word processor have built-in converters to convert from their internal format to HTML format. For example

    • FrameMaker, Office2007

chow


Web delivery systems l.jpg
Web Delivery Systems

  • Delivery web documents efficiently and reliably to the web clients.

  • Content Distribution and Content Delivery

  • Performance is decided by

    • Web server performance

    • Network path performance

    • Client browser performance.

  • Use multiple physical servers (server farm), and multiple server farms in wide area.

  • New generation of proxy servers/content switches emerge.

chow


Content delivery network cdn l.jpg

Host Server

Sprint

UUnet

Gloobix

QWest

Clients

Content Delivery Network (CDN)

Slow Response

Huge Requests

@Home

Clients

PSINet

Server Crash

MindSpring

Clients

chow


Content delivery problems l.jpg
Content Delivery Problems

http://www.akamai.com

chow


Use client cache client side cache server l.jpg

Host Server

QWest

Use Client Cache/Client Side Cache Server

Fewer Requests

Clients

@Home

PSINet

Fast Response

Sprint

UUnet

Client

Cache

Gloobix

MindSpring

Client

Side

Cache

Server

Clients

Clients

chow


Use mirror sites l.jpg

Fewer Requests

Host Server

UUnet

Sprint

Server

Gloobix

QWest

MirrorSite

Use Mirror Sites

Need improvement by guiding the selection of mirror servers with server load/network bandwidth measurement

Mirror Site

Clients

@Home

PSINet

Clients

MindSpring

Fast Response

Clients

chow


Edge network cache servers l.jpg

Cache

Server

Cache

Server

Cache

Server

Cache

Server

Fewer Requests

Host Server

Sprint

UUnet

Server

Gloobix

QWest

MirrorSite

Mirror Site

Edge Network Cache Servers

Fast Response

Clients

@Home

PSINet

Client

Cache

MindSpring

Edge

Network

Cache

Server

Client

Side

Cache

Server

Clients

Clients

chow



Fig 2 model architecture for a locally distributed web system l.jpg
Fig. 2 1). Model architecture for a locally distributed Web system

chow


Fig 3 architecture of a cluster based web system l.jpg
Fig. 3 1). Architecture of a cluster-based Web system

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Fig 4 architecture of a virtual web cluster l.jpg
Fig. 4 1). Architecture of a virtual Web cluster

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Fig 5 architecture of a distributed web system l.jpg
Fig. 5 1). Architecture of a distributed Web system

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Content distribution l.jpg
Content Distribution 1)

  • Secure, automate content/application distribution to single (multiple server)/wide area Internet sites.

  • Provide replication, synchronization, staged rollout and roll back.

  • With revision control, transmit only updates.

  • User-defined file distribution profiles/rules

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Content delivery problem l.jpg
Content Delivery Problem 1)

  • Cache Location Problem: Where to put cache servers?

  • How many are needed?

  • When/where/how to push/delivery the content?

  • How about dynamic content?

chow


Akamai edge delivery service l.jpg
Akamai 1) Edge Delivery Service

  • Peering Bottleneck Problem: Access traffic evenly spread over 7400+ networks (no one over 5%; most << 1%) Need to put edge servers in many networks.

  • Akamai delivers between 10-20% Internet traffic, 10B interactions/day.

  • 1 hop to 85% of the world’s Internet users.

  • http://www.akamai.com/html/technology/nocc.html

  • http://www.akamai.com/html/technology/medium_res.asx

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F5 web system product l.jpg

Site II 1)

losangeles.domain.com

Internet

Internet

Site I

newyork.domain.com

Router

3-DNS

BIG-IP

BIG-IP

Local DNS

GLOBAL-SITE

Webmaster

Site III

tokyo.domain.com

Server Array

User

london.domain.com

F5 Web System Product

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Big ip delivers high availability l.jpg
BIG/ip - Delivers High Availability 1)

  • E-commerce - ensures sites are not only up-and-running, but taking orders

  • Fault-tolerance - eliminates single points of failure

  • Content Availability - verifies servers are responding with the correct content

  • Directory & Authentication - load balance multiple directory and/or authentication services (LDAP, Radius, and NDS)

  • Portals/Search Engines – Using EAV administrators perform key-word searches

  • Legacy Systems - Load balance services to multiple interactive services

  • Gateways – Load balance gateways (SAA, SNA, etc.)

  • E-mail (POP, IMAP, SendMail) - Balances traffic across a large number of mail servers

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3dns intelligent load balancing l.jpg
3DNS Intelligent Load Balancing 1)

  • Intelligent Load Balancing

    • QoS Load Balancing

      • Quality of Service load balancing is the ability to select apply different load balancing methods for different users or request types

    • Modes of Load Balancing

      • Round Robin Ratio

      • Least Connections Random

      • User-defined Quality-of-Service Round Trip Time

      • Completion Rate (Packet Loss) BIG/ip Packet Rate

      • Global Availability HOPS

      • Topology Distribution Access Control

      • LDNS Round Robin Dynamic Ratio

      • E-Commerce

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Global site replicate multiple servers and sites l.jpg
GLOBAL-SITE Replicate Multiple Servers and Sites 1)

  • File archiving engine and scheduler for automated site and server replication

  • BIG-IP controls server availability during replication and synchronization

    • Gracefully shutdown for update

    • update in group/scheduled manner

  • FTP provides transferring files from GLOBAL-SITE to target servers (agent free, scalable)

  • RCE for source control

  • No client side software

  • Complete, turnkey system (appliance)(adapt from F5 presentation)

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Intel netstructure l.jpg
Intel NetStructure 1)

  • Routing based on XML tag (e.g., given preferred treatment for buyers, large volume)

  • http://www.intel.com/network/solutions/xml.htm

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Simple web access example step1 l.jpg
Simple Web Access Example: Step1 1)

  • Someone requests a document using a browser (Web Client) on a computer connected to Internet

  • On a browser window Type in a URL, http://news.netcraft.com/archives/web_server_survey.html

    • Equivalent of %telnet www.netcraft.co.uk 80 > outGET /survey/ HTTP/1.0<cr><cr>

    • Here <cr> is “carriage return” entered by pressing “enter”key

  • The browser parses the URL,

    • obtains domain name of url, www.netcraft.co.uk

    • asks Domain Name Server (DNS) for translating the domain name to the IP address

    • with IP address the client computer set up a HTTP connection to the server

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Computer network l.jpg
Computer Network 1)

Local Area Network (LAN): a private-owned network within a single building or campus of up to a few kilometer in size (Tanenbaum).

Wide Area Network (WAN): a network that spans a large geographical area, often a country or continent, and connects LANs or MANs. It consists of transmission line (called circuits, channels, or trunks) and switching elements (called switching nodes, data switching exchanges or router).

web

client

web

server

DNS

DNS

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Protocol and protocol layer l.jpg
Protocol and Protocol Layer 1)

  • A set of rules for achieving a global objective exercised by geographically distributed nodes. (Robert Gallager, Prof. EE MIT)

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Simple web access example step2 l.jpg
Simple Web Access Example: Step2 1)

Browser sends the following character string to serverGET /survey/ HTTP/1.0User-agent: Mosaic for X windows/2.4Accept: text/plainAccept: text/htmlAccept: image/*

httpd server

  • parses the request according to HTTP protocol 1.0

  • interprets rest of the metainfo for browser capabilities

  • Maps the /survey/ to c:/InetPub/wwwroot/survey/default.htma file path in its file system according to server configuration.

  • retrieves c:/InetPub/wwwroot/survey/default.htm or index.html

  • sends information back using HTTP/1.0 format

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Simple web access example step3 l.jpg
Simple Web Access Example: Step3 1)

  • Server replies information using HTTP/1.0 format

    HTTP/1.0 200 Document follows

    Date: Tue, 19 Jan 1999 18:10:20 GMT

    Server: NCSA/1.5

    Content-type: text/html

    <html>

    <head><title>Netcraft Web Server Survey</title></head>

  • Server close file, set certain timeout and wait for next subsequent requests, such as images/midi files referenced in the web page. (called keep-alive connection). When time expires, disconnect the connection.

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Simple web access example step3a l.jpg
Simple Web Access Example: Step3a 1)

  • Browser send GET /sample.htm HTTP/1.0

  • Server replies

    HTTP/1.0 404 Object Not Found

    Content-Type: text/html

    <body><h1>HTTP/1.0 404 Object Not Found

    </h1></body>

  • Server close file, network connection, wait for next request

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Simple web access example step4 l.jpg
Simple Web Access Example: Step4 1)

  • Browser receives http response, a web document with HTML tags, from the server.

  • Browser parses/processes the HTML document, display the document content according the tags.

  • When other images/audio/video data are referenced by <img> <object> <applet> tags, the browser initiates the retrieval of those data.

  • Some of them will http requests to the same web servers. That is the reason why keep-alive connection improves the web server throughput.

  • A URL request may trigger many http requests to several web servers.

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Slide35 l.jpg
HTTP 1)

  • HTTP1.0/1.1http://www.w3.org/Protocols/rfc2068/rfc2068

  • A HTTP request consists of

    • method: GET, HEAD, POST, PUT, DELETE,

    • Universal Resource Identifier (URI)

    • Protocol version

    • other info to modify or supplement the request

      • If-Modified-Since: (only return object if it is newer the date

      • authorization: (user password or other authentication as required)

      • accept: application/postscript

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Http response l.jpg
HTTP Response 1)

  • consists of

    • status line (success or failure)

      HTTP/1.1 400 Bad Request200 (Document Follow), 301 (Move Permanently), 302 (Move Temporarily), 304 (Not Modified), 401 (Unauthorized), 402 (payment required), 403 (Forbidden), 404 (Not Found), 500 (server error)

    • description of the information (metaheader)

      • Server, Date, Content-Length, Content-Type, Content-Encoded, Last Modified

    • actual info requested

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Content type mime type l.jpg
Content-Type: MIME Type 1)

MIME Type File Extension

text/plain txt, default (most server)

text/html htm, html

application/postscript ps

application/ms-powerpoint ppt

application/x-javascript js

image/gif gif

image/jpeg jpg

audio/midi mid

video/mpeg mpg

x-world/x-vrml wrl

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Configure mime types l.jpg
Configure MIME Types 1)

  • For supporting new mime types, both web server and web client may need to be reconfigured.

    For web server,

  • Include new mime.type definition in the mime.types file of the configuration directory of the web server

  • By default, most servers deliver unknown type as text/plainbrowser then may display them as “gibberish”

  • Restart the web server

    For web client,

  • Specify external viewer associated with the mime type

  • Or, install the plug-in associate with the mime type

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Brief survey of web servers l.jpg
Brief Survey of Web Servers 1)

  • http://www.w3c.org/hypertext/WWW/Servers.html

  • Jigsaw, http://www.w3c.org/Jigsaw/

  • http://java.sun.com/products/java-servers/

  • http://www.yahoo.com/computers_and_Internet/Internet/World_Wide_Web/HTTP/Servers

  • http://www.netcraft.co.uk/Survey/

  • “Web Server Technologies” by Nancy J. Yeager and Robert E. McGrath, Morgan Kaufmann 1996.

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Cgi script example l.jpg
CGI Script Example 1)

  • Client type http://owl.uccs.edu/cgi-bin/chow/uptime.pl

  • or click on <A HREF =“http://owl.uccs.edu /cgi-bin/chow /uptime.pl”> Show the load on owl</A> in a web page.

  • uptime.pl

    #!/usr/bin/perl

    $UPTIME = '/usr/ucb/uptime';

    select(STDOUT); $| =1; #make output unbufferedprint "Content-type: text/html\n\n";

    if (-x $UPTIME) { exec($UPTIME);

    } else { print "cannot find uptime command on this system.\n"; exit(1); }

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Cgi script example step 2 l.jpg
CGI Script Example (Step 2) 1)

  • Web browser sends “GET /cgi-bin/chow/uptime.pl HTTP/1.0” to owl.uccs.edu

  • httpd server at owl parses the request and discovers that a perl script needs to be executed.

  • It locates the script in the file system.

  • Create the execution environment

    • starting a process with appropriate shell environment variable set

    • with STDIN from httpd program

    • with STDOUT to httpd

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Cgi script example step 3 l.jpg
CGI Script Example (Step 3) 1)

  • uptime.pl generates

    Content-type: text/plain

    15:55 up 18 days, 7:15, 5 users, load average: 0.89, 0.81, 0.79

  • It was sent over STDOUT back to httpd

  • httpd add

    HTTP/1.0 200 OK

    Server: Netscape-Communications/1.1

    Date: Tuesday, 27-Jan-98 23:12:45 GMT

  • httpd relays the text string back to the web browser

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What problems can occur l.jpg
What problems can occur? 1)

  • How to detect a script running infinite loop?

  • How to detect a hung script?

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Handle multiple requests l.jpg
Handle Multiple Requests 1)

  • Can’t afford sequential processing, since some requested documents are big.

    Three basic approaches:

    1. Fork a new child process: Cloning a copy of httpd

    2. Use multithread (if the OS or language support it)e.g., IIS, Java Web Server, Jigsaw

    3. Spread the load among several helper programse.g., Apache

  • Apache allows the starting , min, max # of child web server processes to be specified in a configuration file. It can dynamically adjust to the load.

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More than one web service on the same server platform l.jpg
More than One Web Service on the Same Server Platform 1)

  • Run different/same httpd programs on different ports

    http://www.server.org/intro.html (port 80 by default)

    http://www.server.org:8080/intro.html (port 8080)

    http://www.server.org:8081/intro.html (port 8081)

  • They may have different document trees, content, and access control, and serve different user groups (customer, sales, authorized)

  • Note that running program at any port < 1024 requires root privilege.

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Virtual hosting l.jpg
Virtual Hosting 1)

  • To allow one server to server requests with multiple IP addresses.

  • It is a low cost option for clients that want own id and cannot afford a separate machine/connection.

  • Hosting other domain names on the same machine.

    • http://www.a.com/home.html

    • http://www.b.com/home.html

  • Require OS with virtual host support.

  • Assign Multiple IP numbers to the same interfaceusing the ifconfig command in UNIX or ipconfig in NT.

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Assign multiple ip address to the same interface l.jpg
Assign Multiple IP Address to the Same Interface 1)

  • On FreeBSD, execute

    ifconfig ep0 192.168.123.2

    ifconfig ep0 192.168.123.3 alias netmask 0XFFFFFFFF

    ifconfig ep0 192.168.124.1 alias

    (netmask option is used to suppress error msg)

  • On Linux, execute

    ifconfig eth0:0 192.168.123.3 192.168.124.1

    you may add

    # route add -host 192.168.123.3 dev eth0:0

    # route add -host 192.168.124.1 dev eth0:0

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New hosting technique l.jpg
New Hosting Technique 1)

  • Set up virtual machines for each customer

  • Related software packages:

    • User mode Linux

    • VMWare ESX and Virtual Center/Infrastructure.

    • MS VS 2005

  • Utility Computing (On-Demand Computing)

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Improving www delivery systems l.jpg
Improving WWW Delivery Systems 1)

  • Currently network is bottleneck.

  • The retrieval of web pages can be improved by

    • increasing network bandwidth, e.g., ADSL link

    • reducing round trip, e.g., use client side programming to check data with Java/Javascript

    • caching (both at client and proxy cache server)

    • increase # and processing power of web servers

    • load balancing by partitioning client-server requests

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Large web sites l.jpg

to Internet 1)

RRDNS

DMZ Firewall

Router/Firewall

Web

Server1

Internal

Proxy Server

Web

Server9

HA NFS Server

HA NFS Server

Router/Firewall

To Intranet

Web

Pages

Large Web Sites

  • Mapping the request, e.g., ftp.netscape.com, evenly across a set of server, e.g., ftp[1-28].netscape.com

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Cisco distributed director l.jpg
CISCO Distributed Director 1)

  • Distributed Director uses, the Director Response Protocol (DRP), a UDP-based application for querying DRP server agent for BGP and IGP routing table metrics between distributed servers and clients, and perform load distribution.

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Internet caching l.jpg
Internet Caching 1)

  • Harvest/SQUID Cache: hierarchical, 42% ftp bw reduction

  • Client/Proxy Cache. Local Small, 65% bw reduction

  • Server Push Cache: Gwertzman and Seltzer (cornell)

  • Distributed Internet Cache: Povey and Harrison (uq) hierarchical index on tree top, content on the leave

  • Cachemesh: Wong and Crowcroft (ucl)cache routing table for reducing search overhead

  • WebWave: Heddaya and Mirdad (bu)Cache on Route, Tree Load Balancing &Load Diffusion

  • Adaptive Web Caching: Zhang, Floyd, JacobsonSelf-configuration Cache Group, Multicast.

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Havest squid object cache l.jpg
Havest/SQUID Object Cache 1)

  • Hierarchical Cache: Danzig, Hall & Schwartz shows it reduces 42% of FTP traffic. Place Big caches between regional networks and backbone. Byte*hop as metric

  • Havest Object Cache: manual configurated hierarchical cache system. Client uses Internet Cache Protocol (ICP) to (recursively) query Sibling and Parent caches

  • NLANR SQUID Object Cache. Internet hierarchical cache system. Problems:

    • 14 separate Australian branches from US

    • CA content sources distribute content through East Coast root cache, back to CA clients.

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Server push cache l.jpg
Server Push Cache 1)

  • Assume a network with a lot of push cache servers.

  • Show server initiated cache (push cache) can be combined with client cache to be very effective.

  • Use network topology info and access history to decide which push cach server to place replica.

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Distributed internet cache l.jpg
Distributed Internet Cache 1)

  • Povey and Harrison (Univ. of Queenland, Brisbane)

  • Address hierarchical cache problem

  • Hierarchical structure for data searhing only.with mapping info on non-leave nodes, content on the leave.

  • After retrieving a new page, send advertisment up the tree hierarchy. Non-leave node in the path store the advertisement (url, cache loc.) in its table.

  • Disadvantages: increase load on leave caches.

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Cachemesh l.jpg
Cachemesh 1)

  • Wong and Crowcroft (University College London).

  • Client search cache routing table for cache location.

  • A collection of co-operating caches use Cache Information Exchange Protocol (CIEP) to add/delete entries to the cache routing table.

  • Web site as unit for cache table entries

  • Collision resolution when multiple cache servers claim responsibility (based on freq.) for a web site: use random CIEP_ADD/DELETE sending delay.

  • Realistic metrics to be used for selecting cache server.

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Webwave l.jpg
WebWave 1)

  • Heddaya and Mirdad (Boston Univ.)

  • No directory lookup or cache search.

  • Cache lies along the route to the source.

  • Assume cache server can change filter rules in router to intercept and server the web requests.

  • Define Optimal Tree Load Balancing (TLB).

  • Provide load diffusion algorithms that achieve TLB.

  • Only address single tree for now.

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Adaptive web cache l.jpg
Adaptive Web Cache 1)

  • Zhang (UCLA), Floyd, Jacobson (NRG, LBNL)

  • New DARPA-funded research project.

  • Focus on scalability and self-configuration.

  • Self-configuration Cache Group use Cache Group Management Protocol (CGMP).

  • IP Multicast delivery.

  • Cache server may join multiple cache groups (select multi-homed hosts as cache server)

  • Ideally one cache server forward requests to the source.

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Dynamic server selection one candidate architecture l.jpg

Web 1)

Server1

Web

Server2

Web

Server8

Web

Server9

LB Agent

LB Agent

LB Agent

LB Agent

Dynamic Server Selection One candidate architecture

Server push

load status

Client probe

response time

client

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Novel server selection technique fei et al ammar git cc 97 24 l.jpg
Novel Server Selection Technique 1)Fei et al (Ammar) [GIT-CC-97-24]

  • Use application layer anycast to select the best geographically separated web servers.

  • Server push (server load status) to resolver.

  • Only push when load change over threshold.

  • Client (resolver) probe (response time of the server)

  • Retrieve fixed size document in each server.

  • Avoid oscillation by returning one server from a set of equivalent servers.

  • Investigate the impact of push/probe frequency on response time.

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Application layer anycast architecture l.jpg

Resolver 1)

Server

Probes

Content

Server

Probe

Client

Performance

Update

Probe

Update

Server Pushes

(multicast)

Push

Daemon

Name

Resolver

client/server

comm.

Anycast

Query/Response

Anycast-ware

Client

Application-layer Anycast Architecture

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Response time varying with push and probe frequency l.jpg
Response Time Varying with Push and Probe Frequency 1)

Server push twice/min

Client Probe once/6min

Server push 12 times/min

Client probe once/10min

vs.

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Dynamic server selection vs load balancing in servers l.jpg
Dynamic Server Selection vs. 1)Load Balancing in Servers

  • In Fei et al’s work, after every client chooses the lightest server, it becomes the heavy loaded server.

  • Next round, every client swings to next lightest server and results in oscillation in server selection.

  • How to damp the oscillation:

    • Anycast resolvers return a set of good servers

    • A threshold is used to add/delete good server set

  • User response time vs. System throughputDynamic serverLoad Balancingselectionin Servers

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Wan load balancing architecture l.jpg

LB Agent 1)

LB Agent

Content

Server

Probe

Client

Probe

Client

Probe

Update

Probe

Update

Push

Daemon

LB

Coordinator

LB

Coordinator

LB

Query/Response

LB

Query/Response

LB

Client

LB

Client

WAN Load Balancing Architecture

LBed Server

Probes

Performance

Update

Server Pushes

(multicast)

LBCoord.

Protocol

client/server

comm.

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Wan load balancing architecture 2 l.jpg

LB Agent 1)

LB Agent

Content

Server

Probe

Client

Probe

Client

Probe

Update

Probe

Update

LB

Coordinator

LB

Coordinator

LB

Query/Response

LB

Query/Response

LB

Client

LB

Client

WAN Load Balancing Architecture-2

Server

Probes

LBCoord.

Protocol

client/server

comm.

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Wan load balancing architecture 3 l.jpg

LB Agent 1)

LB Agent

Server

Probes

Probing

module

Probing

Module

Content

Server

Probe

Update

Probe

Update

Control

Control

LBCoord.

Protocol

LB

Coordinator

LB

Coordinator

Traffic

Update

Traffic

Update

client/server

comm.

Traffic

Control

Traffic

Control

LB

Query/Response

Load Balancing System

LB

Client

LB

Client

LB

Client

LB

Client

WAN Load Balancing Architecture-3

LB

Query/Response

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Functions of lb coordinator l.jpg
Functions of LB coordinator 1)

  • Collect server load, network status, and traffic status from probing and traffic control module

  • Share the server and traffic status with other LB coordinators via LB coordinating protocol

  • Run load balancing algorithm that

    • directs the client requests (macro control)

    • dynamically regulates the client-server traffic (micro control)

  • Control the probing frequency of probing module

  • Regulate the traffic of client-server communication

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Status collection in wlb system l.jpg
Status Collection in WLB system 1)

  • Passive traffic monitoring on client-server comm.

  • Server load report from other LB coordinators

  • Active probing on server and network loads when there is no traffic status reports

  • Research issues:

    • traffic monitoring system design

    • efficiency, accuracy, coordination of probing system

    • derive server and network load from traffic data

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Traffic control in wlb system l.jpg
Traffic Control in WLB System 1)

  • Admission control (Macro level Control)

    • Estimate the load of the requests

    • Direct the requests

  • Taffic grooming/shapping (Micro level control)

    • At what protocol level (TCP, IP?)

    • At which module/interface (Router? Layer4/Content/Web switch)

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Important web sites l.jpg
Important Web Sites 1)

  • http://www.w3c.org/

  • http://developer.netscape.com/

  • http://java.sun.com/

  • http://www.microsoft.com/workshop/default.asp

  • http://www.apache.org/

  • http://www.netcraft.co.uk/Survey/

  • http://web.mit.edu/afs/athena/user/w/s/wsmart/WEB/HTMLtutor.html

  • ...

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Useful references l.jpg
Useful References 1)

  • Oreily’s Web series

    • HTML, CGI, Dynamic HTML, Programming Perl

  • “Web Server Technologies” by Nancy J. Yeager and Robert E. McGrath, Morgan Kaufmann 1996.

  • HTML+CGI

  • World Wide Web Beyond the Basics, edit by Marc Abrams, Prentice Hall, 1998

  • MS Technical Support for IIS, self learning manual.

  • How to setup and maintain a web sites, L. Stein.

  • Web Server Tuning

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