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<html><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"><!--Converted with jLaTeX2HTML 2002 (1.62) JA patch-1.4patched version by: Kenshi Muto, Debian Project.LaTeX2HTML 2002 (1.62),original version by: Nikos Drakos, CBLU, University of Leeds* revised and updated by: Marcus Hennecke, Ross Moore, Herb Swan* with significant contributions from: Jens Lippmann, Marek Rouchal, Martin Wilck and others --><HTML><HEAD><TITLE>36.4.3 PagePool/ProxyTrace</TITLE><META NAME="description" CONTENT="36.4.3 PagePool/ProxyTrace"><META NAME="keywords" CONTENT="everything"><META NAME="resource-type" CONTENT="document"><META NAME="distribution" CONTENT="global"><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859-1"><META NAME="Generator" CONTENT="jLaTeX2HTML v2002 JA patch-1.4"><META HTTP-EQUIV="Content-Style-Type" CONTENT="text/css"><LINK REL="STYLESHEET" HREF="everything.css" tppabs="http://www.isi.edu/nsnam/ns/doc/everything.css"><LINK REL="next" HREF="node508.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node508.html"><LINK REL="previous" HREF="node506.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node506.html"><LINK REL="up" HREF="node504.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node504.html"><LINK REL="next" HREF="node508.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node508.html"></HEAD><BODY ><!--Navigation Panel--><A NAME="tex2html9208" HREF="node508.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node508.html"><IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="file:/usr/share/latex2html/icons/next.png"></A> <A NAME="tex2html9202" HREF="node504.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node504.html"><IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="file:/usr/share/latex2html/icons/up.png"></A> <A NAME="tex2html9196" HREF="node506.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node506.html"><IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="file:/usr/share/latex2html/icons/prev.png"></A> <A NAME="tex2html9204" HREF="node1.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node1.html"><IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="file:/usr/share/latex2html/icons/contents.png"></A> <A NAME="tex2html9206" HREF="node590.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node590.html"><IMG WIDTH="43" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="index" SRC="file:/usr/share/latex2html/icons/index.png"></A> <BR><B> Next:</B> <A NAME="tex2html9209" HREF="node508.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node508.html">36.4.4 PagePool/Client</A><B> Up:</B> <A NAME="tex2html9203" HREF="node504.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node504.html">36.4 Page pools</A><B> Previous:</B> <A NAME="tex2html9197" HREF="node506.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node506.html">36.4.2 PagePool/CompMath</A>   <B> <A NAME="tex2html9205" HREF="node1.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node1.html">Contents</A></B>   <B> <A NAME="tex2html9207" HREF="node590.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node590.html">Index</A></B> <BR><BR><!--End of Navigation Panel--><H2><A NAME="SECTION07243000000000000000">36.4.3 PagePool/ProxyTrace</A></H2><P>The above two page pool synthesize request stream to a single web pageby two random variables: one for request interval, another forrequested page ID. Sometimes users may want more complicated requeststream, which consists of multiple pages and exhibits spatial localityand temporal locality. There exists one proposal (SURGE[<A HREF="node589.html#Barf98:WebWorkload" tppabs="http://www.isi.edu/nsnam/ns/doc/node589.html#Barf98:WebWorkload">3</A>]) which generates such request streams, we choose to provide analternative solution: use real web proxy cache trace (or servertrace). <P>The class PagePool/ProxyTrace uses real traces to drivesimulation. Because there exist many web traces with differentformats, they should be converted into a intermediate format beforefed into this page pool. The converter is available at http://mash.cs.berkeley.edu/dist/vint/webcache-trace-conv.tar.gz.It accepts four trace formats: DEC proxy trace (1996), UCBHome-IP trace, NLANR proxy trace, and EPA web server trace. Itconverts a given trace into two files: pglog and reqlog. Each line inpglog has the following format:<DIV ALIGN="CENTER"></DIV><PRE>[<serverID> <URL_ID> <PageSize> <AccessCount>]</PRE><DIV ALIGN="CENTER"></DIV><P>Each line, except the last line, in reqlog has the following format:<DIV ALIGN="CENTER"></DIV><PRE>[<time> <clientID> <serverID> <URL_ID>]</PRE><DIV ALIGN="CENTER"></DIV><P>The last line in reqlog records the duration of the entire trace andthe total number of unique URLs:<DIV ALIGN="CENTER"></DIV><PRE>i <Duration> <Number_of_URL></PRE><DIV ALIGN="CENTER"></DIV><P>PagePool/ProxyTrace takes these two file as input, and use them todrive simulation. Because most existing web proxy traces do notcontain complete page modification information, we choose to use abimodal page modification model [<A HREF="node589.html#Cao97:CacheConsistency" tppabs="http://www.isi.edu/nsnam/ns/doc/node589.html#Cao97:CacheConsistency">7</A>]. Weallow user to select of the pages to have one random pagemodification interval generator, and the rest of the pages to haveanother generator. In this way, it's possible to let pages to bedynamic, i.e., modified frequently, and the rest static. Hot pages areevenly distributed among all pages. For example, assume 10% pages aredynamic, then if we sort pages into a list according to their popularity,then pages 0, 10, 20, are dynamic, rest are static. Becauseof this selection mechanism, we only allow bimodal ratio to change inthe unit of 10%. <P>In order to distribute requests to different requestors in thesimulator, PagePool/ProxyTrace maps the client ID in the traces torequestors in the simulator using a modulo operation. <P>PagePool/ProxyTrace has the following major OTcl methods:<P><BR><BR><P>An example of using PagePool/ProxyTrace is available at /tcl/ex/simple-webcache-trace.tcl. <P><HR><!--Navigation Panel--><A NAME="tex2html9208" HREF="node508.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node508.html"><IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="file:/usr/share/latex2html/icons/next.png"></A> <A NAME="tex2html9202" HREF="node504.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node504.html"><IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="file:/usr/share/latex2html/icons/up.png"></A> <A NAME="tex2html9196" HREF="node506.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node506.html"><IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="file:/usr/share/latex2html/icons/prev.png"></A> <A NAME="tex2html9204" HREF="node1.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node1.html"><IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="file:/usr/share/latex2html/icons/contents.png"></A> <A NAME="tex2html9206" HREF="node590.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node590.html"><IMG WIDTH="43" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="index" SRC="file:/usr/share/latex2html/icons/index.png"></A> <BR><B> Next:</B> <A NAME="tex2html9209" HREF="node508.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node508.html">36.4.4 PagePool/Client</A><B> Up:</B> <A NAME="tex2html9203" HREF="node504.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node504.html">36.4 Page pools</A><B> Previous:</B> <A NAME="tex2html9197" HREF="node506.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node506.html">36.4.2 PagePool/CompMath</A>   <B> <A NAME="tex2html9205" HREF="node1.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node1.html">Contents</A></B>   <B> <A NAME="tex2html9207" HREF="node590.html" tppabs="http://www.isi.edu/nsnam/ns/doc/node590.html">Index</A></B> <!--End of Navigation Panel--><ADDRESS>2003-09-23</ADDRESS></BODY></HTML>⌨️ 快捷键说明
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