4WWW95: making WWW
caching servers cooperate
- radhika maplani,
university of california at berkeley
- jacob lorch, university
of california at berkeley
- david berger, Enterprise Integration Technology
limitations on caching today:
- client caching: has a low hit rate
- single proxy cache: might become a bottle neck
- multiple proxy caches: they do not cooperate
make multiple caching proxy servers work together:
- the implementation is based on CERN's httpd
- proxy servers use IP multicast to communicate with each other
how this basically works:
- a browser sends a HTTP request to one of the proxy servers
- if the proxy server has the document, it sends it back to the client and
we are done
- if the proxy server doesn't have the document in its cache, it sends a
request for that document to the other proxy servers using IP multicast.
- if any of the other proxy servers has the document, it sends it to the
requesting proxy server which forwards the document to the client
- if none of the proxy servers has the document, the request is passed to
the server specified in the URL and the request is handled as usual
a possible extension would be a so called "proxy redirect":
instead of transferring the document from one proxy server to another, the
first proxy server could send a proxy redirect message back to the client, so
the client could request the document directly from the proxy server which has
the document in its cache. to implement such a mechanism, an extension to the
HTTP standard would be necessary. such an extension is proposed and might
become part of the HTTP V1.x standard.
back to 4WWW95 main document.
4WWW95 caching_1 / 28-jan-1999 (ra) /
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