Proxy Server Experiment and the Changing Nature of the Web

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Proxy Server Experiment and the Changing Nature
of the Web

• The WWW has witnessed significant growth in the
  last few decades this is due partly to the large
  numbers of users and the type of traffic
  generated. A typical solution which is not
  scalable is to increase the bandwidth. Since
  increasing the bandwidth can be achieved with
  associated monthly cost, many organizations are
  using proxy server to provide adequate access and
  response time to their ever growing number of
  users requesting internet connectivity.

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DATA COLLECTION

• The access logs for our study were collected from
  three different proxy servers. Two of the proxy
  servers are located at the Obafemi Awolowo
  University, Ile-Ife, Nigeria and the third proxy
  server at the International Center for
  theoretical Physics, Trieste, Italy we refer to
  the proxies as
• ASOJU used by the academic network
• CAFÉ used by the campus cyber cafes and
• ICTP used by the ICTP network.

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PROXY SERVER PERFORMANCE EVALUATION

• We observe that the total requests in the reduced
  data for ASOJU is smaller, this is expected since
  about 46 of the total request are errors due to
  client authentication.This is possible since
  ASOJU runs proxy authentication.

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• The use of proxy server could help provide
  adequate access and response time to large
  numbers of World Wide Web (WWW) users requesting
  previously accessed page. While some studies have
  reported performance increase due to the use of
  proxy servers, a study reported performance
  decrease associated with the use of proxy server.
  Due to lack of recently published scholarly
  article that test the performance of proxy
  server, we carry out an in-depth study of the
  behavior of a proxy server over a six month
  period. The result of the study showed that hit
  ratios of the proxy servers range between 21 to
  39 and over 70 of web pages are dynamic. The
  study indicates the effectiveness of the proxy
  server and helps evaluate the tradeoff between
  money spent on higher bandwidth lower latency
  connections, versus the cost/performance of using
  a caching intermediary.

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Literature Review

• Organizations that use Web proxy servers report
  that the proxy servers caching technology has
  greatly reduced network costs. Many organizations
  bought proxy servers in order to decrease access
  time. However, they received an unexpected
  benefit when caching reduced traffic on the
  Internet connections. Industry analysts report
  that proxy servers often reduced traffic enough
  to eliminate the need to add bandwidth servers.
  The demand for proxy servers among businesses,
  organizations, government, and academic was been
  strong. Microsoft, Netscape and Novell all offer
  proxy-server software as part of their Internet
  server suites. The demand is understandable given
  the reported increases in performance from users.
  Reported performance enhancements from proxy
  server for end users is typically about 20 to
  25, i.e., a one-quarter decrease in access time.
  Organizations also reported high volume of proxy
  server cache access, as high as 40 and extremely
  active caches with thousands of Web documents

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The Network

• The experiment was conducted at the United States
  Military Academy (USMA), which is a four year,
  undergraduate institution. USMA graduates about
  1000 students, called cadets, per year. Almost
  all of the graduating cadets immediately serve in
  the US Army.
• The USMA network at has a Fiber Distributed Data
  Interface (FDDI) backbone at 100 Mbps. About half
  of our users are connected to the backbone via
  dedicated 10 Mbps lines. Other users are
  connected to the backbone via shared 10 Mbps
  lines. Our network is connected to the Web via
  two (2) connections, one DREN and one NIPRNET.
  DREN is the Defense Research Engineering Network
  and NIPRNET is uNclassified (but sensitive)
  Internet Protocol Routing NETwork). DREN is
  primarily for our education needs. NIPRNET is the
  military Internet. Both run at about T1 speeds,
  1.5Mbps. This network serves the approximately
  four thousand cadets, the faculty and staff of
  the institution, plus the various staff agencies
  of the military post.

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Results and Explanation

• We were expecting to see a substantial
  performance gain by caching common documents that
  many users on the USMA visit repeatedly. Based on
  the architecture of our network, as explained
  above, the proxy server should have retrieved a
  large number of cached documents and delivered
  these at close to USMA network speeds (100 Mbps
  around the backbone and generally 10 Mbps to the
  user). Unfortunately, this did not happen. As an
  example, from 0010 hrs to 1945 hrs on 17 December
  1997, the proxy server accepted 290,000 server
  requests. It only served 12,000 documents from
  its cache. This is a 4 hit ratio. We were
  expecting about a 20 hit ratio.

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Conclusion

• For this experiment, we set out to see if the
  growth of the Web had changed the role and
  performance of proxy servers. We conducted a
  14-day experiment and channeled users through a
  proxy server if they wanted to access
  www.microsoft.com, a major Web site. Based on
  previous trade reports, we expected about a 20
  hit ratio. Instead, our hit ratio was one fifth
  of this expectation. We traced the cause to the
  increased use of dynamic Web pages. ,While the
  growth of the Web was not the major factor, it
  appears that as the Web has grown, it has and is
  evolving from a static to a dynamic information
  repository. Under this environment, the role of
  the proxy server will decrease as it less able to
  delivery performance enhancements. Obviously,
  product redesign is in order.

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