Table of Contents
(NOTE: All chapters conclude with a Summary.)
Preface.
Intended Audience.Organization of the Book.
Acknowledgments.
Introduction.
The Basics of Web Caching.The Basics of Web Replication.Beyond
Performance.
I. BACKGROUND.
1. Network Layers and Protocols.
The ISO/OSI Reference Model.Network Components at Different
Layers.Overview of Internet Protocols.
2. The Internet Protocol
and Routing.
Addressing.IP Datagram Header.Routing.Routing within ASs.Routing
between ASs.Multicast.
3. Transmission Control Protocol.
Segment Header.Opening a Connection.Closing a Connection.Flow
Control.Congestion Control.Retransmission.
4. Application
Protocols for the Web.
Uniform Resource Locators.The Domain Name System.Name Hierarchy.The
DNS Protocol.The HyperText Transfer Protocol.The HTTP Request.The
HTTP Response.The HTTP Message Exchange.Hyperlinks and Embedded
Objects.
5. HTTP Support for Caching and Replication.
Conditional Requests.Conditional Headers Used for
Caching.Conditional Headers Used for Replication.Age and Expiration
of Cached Objects.Request Redirection.Range Requests.The
Cache-Control Header.Cache-Control Header Directives in
Requests.Cache-Control Header Directives in Responses.Example of
the Cache-Control Header.Storing State for a Stateless Server:
Cookies.Support for Server Sharing.Expanded Object
Identifiers.Learning the Proxy Chain.Cacheability of Web
Content.
6. Web Behavior Rules of Thumb.
Evaluation Methods.Live Measurements.Trace-Based
Methods.Benchmarking.Object Size.Object Types and
Cacheability.Object Popularity.Locality of Reference.Temporal
Locality.Spatial Locality.Rate of Object Modifications.Other
Observations.
II. WEB CACHING.
7. Proxy Caching: Realistic Expectations.
Do Proxy Caches Deserve a Hearing?Latency Reduction.An Optimistic
Bound on Latency Reduction.A Pessimistic View of Latency
Reduction.TCP Connection Caching.Connection Caching versus Data
Caching.TCP Connection Splitting.Environment-Specific TCP
Optimizations.Bandwidth Savings.Proxies and Streaming Media.
8.
Proxy Deployment.
Overview of Internet Connectivity Architectures.Nontransparent
Proxy Deployment.Explicit Client Configuration.Browser
Autoconfiguration.Proxy Auto-Discovery.Transparent Proxy
Deployment.Multipath Problem.Interception Mechanisms.Layer 4 Switch
as an Intercepter.Router as an Intercepter.Layer 7 Switch as an
Intercepter.Intercepting Link.Performance Pitfalls.Security and
Access Control Issues.Proxies and Web Server Access Control.Proxies
and Security.
9. Cooperative Proxy Caching.
Shared Cache: How Big Is Big Enough?Issues in Cooperative Proxy
Caching.Location Management.Broadcast Queries.Hierarchical
Caching.URL Hashing.Directory-Based Cooperation.Directory
Structures.Caching on a Global Scale: Proxy Pruning.System
Model.Cache Routing.Vicinity Caching.An Overview of Existing
Platforms.Cache Hierarchies.Caching as a Service of a Network
Access Point.Satellite Broadcast Cache Service.
10. Cache
Consistency.
Cache Validation.The Basic Validation Scenario.Implicit Time to
Live.Fine-Tuning Validation.Asynchronous and Piggyback Cache
Validation.Cache Invalidation.Leases.Subscriptions.Delayed versus
Immediate Updates.Volumes.Volume Lease Protocols.Piggyback and
Delayed Invalidation.Invalidation in Cache Routing.Issues in
Cooperative Cache Consistency.Validation with Cooperative
Proxies.Non-Monotonic Delivery Problem.
11. Replacement
Policy.
Replacement Policy Metrics.Replacement Policy Algorithms.The Value
of Replacement Policy.
12. Prefetching.
Performance Metrics.Performance Bounds of
Prefetching.Taxonomy.Nondata Prefetching.Nontransparent
Prefetching.User Nontransparency.Server Nontransparency.Server Push
versus Client Pull.Information Used in Prefetching
Algorithms.User-Specific Information.Group Information.Multiuser
Information.Prediction Algorithms.Popularity-Based
Predictions.Markov Modeling.Examples of Algorithms using
First-order Markov Modeling.Exploiting Longer Request
Sequences.Structure Algorithms.
13. Caching the
Uncacheable.
A Note on Implementation.Modified Content and Stale Delivery
Avoidance.Cache-Friendly Approaches to Stale Delivery
Avoidance.Utilizing Cached Stale Content.Cookied
Content.Cache-Friendly Usage of Cookies.Caching Cookied Content.The
Semantic Transparency Issue.Expressly Uncacheable Content and Hit
Metering.Cache-Friendly Approaches to Hit Metering.Caching
Expressly Uncacheable Content.Dynamic Content.Cache-Friendly Design
of Dynamic Content.Base Instance Caching.Template
Caching.Base-Instance Caching versus Template Caching.Active
Proxies.
III. WEB REPLICATION.
14. Basic Mechanisms for Request Distribution.
Content-Blind Request Distribution with Full Replication.Client
Redirection.Redirection by a Balancing Switch.Redirection by a Web
Site's DNS.Anycast.Content-Blind Request Distribution with Partial
Replication.Using Surrogates as Server Replicas.Back-End
Distributed File Systems.Content-Aware Request Distribution.Client
Redirection by a Java Applet.HTTP Redirection.Redirection by an L7
Switch.Fine-Granularity Domain Names.
15. Content Delivery
Networks.
Types of CDNs.Delivering Requests to a CDN.Finding Origin
Servers.Request Distribution in CDNs.DNS/Balancing Switch
Redirection.Two-Level DNS Redirection.Anycast/DNS
Redirection.Pitfalls of DNS-Based Request Distribution.Fine-Tuning
DNS Request Distribution.Post-DSN Request Distribution by
Triangular Communication.Post-DNS Request Distribution with HTTP
Redirection and HTML Rewriting.Data Consistency in CDNs.Streaming
Content Delivery.Using Multicast for Streaming Content
Delivery.Using Application-Level Multicast for Streaming Content
Delivery.Constructing a Distribution Tree.Supporting Secure Content
Access.SSL Overview.Performance Impact of Supporting SSL in a
CDN.Key Management.Content Retrieval from the Origin Server.
16.
Server Selection.
Metrics.Proximity Metrics.Server Load Metrics.Aggregate
Metrics.Internet Mapping Services.Aging of
Metrics.Algorithms.Obtaining Passive Measurements.Avoiding
Oscillations.Supporting Client Stickiness.Respecting the Affinity
of Server Caches.Server Selection with Multiple Metrics.DNS-Based
Server Selection.A Typical DNS Server Selection Scheme.Estimating
Hidden Load Factors.Why Choose a Server When You Can Have Them All?
IV. FURTHER DIRECTIONS.
17. Adding Value at the Edge.
Content Filtering.Content Transcoding.Watermarking.Custom Usage
Reporting.Implementing New Services with an Edge Server API.The
ICAP Protocol.Distributed Web Applications.How to Replicate
Applications.Where to Replicate Applications.
18. Content
Distribution Internetworking.
Pros and Cons of CDI.Request Distribution.Content
Distribution.Accounting.
Glossary.
Bibliography.
Index. 0201615703T12172001Promotional Information
In Web Caching and Replication, two AT&T Labs experts bring
together real-world implementations, the latest IETF and W3C
technical standards, and the field's most advanced research,
offering systematic guidance for maximizing Web scalability and
performance. The authors first introduce key concepts of Web
caching and replication.They introduce HTTP's support for caching
and replication, and broadly characterize Web behavior, offering
practical rules of thumb for optimizing performance. Next, they
focus on caching, helping implementers realistically assess proxy
caching, deploy proxies in corporate and ISP networks; and utilize
cooperative proxy caching. They offer in-depth insights into cache
consistency, and caching the "uncacheable" -- including "cookied"
and dynamic content. Part III introduces today's best techniques
for web replication, offering in-depth coverage of content delivery
networks, server selection, content placement, and more. For all
networking professionals, IT professionals, and engineers involved
with building or optimizing Internet services or equipment; for
content delivery specialists and service providers; and for owners
of large sites concerned about scalability and performance.
About the Author
Michael Rabinovich is "one of the few research-ers who
are qualified to write this book" (Pei Cao, Cisco Systems). As a
leading researcher at AT&T Labs, he has closely watched current
trends and state-of-the-art standards and commercial products while
both battling "real-life" technical problems and participating in
new research in Web caching and replication. In addition to
numerous publications in the areas of distributed systems, Web
performance, and transaction management, he is a co-author of the
CRISP distributed proxy cache.
Oliver Spatscheck is a senior technical staff member at AT&T
Labs–Research, where he has been actively involved in building
AT&T's content distribution network. His research publications
span the areas of security, operating systems, and CDNs. He has
also been active in the IETF, working most recently on Content
Distribution Internetworking. He holds a Ph.D. in computer science
from the University of Arizona.
0201615703AB11262001
