Scheduling Updates To Local Cache Content; News Article Caching - HP P4535A - Web Cache Server Appliance Administrator's Manual

Chapter 3

Scheduling updates to local cache content

To further increase the performance of Traffic Server, you can configure it to perform scheduled updates to
the local cache content. This enables you to instruct Traffic Server to explicitly load specific objects into
cache. You might find this especially beneficial when using Traffic Server as a reverse proxy for server
acceleration, enabling you to preload content that you anticipate will be in demand. See
proxy caching‚ on page
You do this by inputting a list of URLs in the Content Management page in Traffic Manager. This modifies
the
update.config
interval of when this update should take place. The UI also enables you to specify a recursion depth for the
URL.
Traffic Server uses this information to determine the URLs for which it is responsible and, for each URL,
derives all recursive URLs if applicable. It then generates a unique, sorted URL list. Using this list, Traffic
Server initiates an HTTP
limits for HTTP concurrency at any given time. The system logs the completion of all HTTP
enabling you to monitor the performance of this feature.

News article caching

Traffic Server can function as a news server or a caching news server. This section provides background
information about Traffic Server news server and the Network News Transfer Protocol (NNTP) caching
features.
News, also known as USENET and discussions, is a system of online discussion groups. NNTP is the protocol
used to retrieve and distribute these discussion groups. News groups exist to discuss just about any subject;
for example,
rec.humor
The articles posted to these groups are propagated around the world. Traffic Server supports NNTP as
specified in RFC 977 and many common extensions and proposed extensions.
To read news articles, users need a news reader, such as Netscape Communicator or Microsoft Internet
Explorer, and access to a news server. Traffic Server is a caching news server. It can be configured to sit
transparently between users and a parent or backing news server, increasing responsiveness for the user and
decreasing network bandwidth use and the load on the parent news server.
Figure 3-3. Traffic Servers caching news articles for a distant NNTP server
33.
file, specifying objects that you want to schedule for update along with the time and
for each un-accessed URL, ensuring that it remains within the user-defined
GET
, ,
talk.religion
Traffic
Server
users
Traffic
Server
users
,
news.answers rec.food.recipes
Web Proxy Caching
Understanding reverse
operations,
GET
, and .
comp.std.unix
Parent
NNTP
Server
16