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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Hello<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Varnish is a key part of a new set of apps we are building -
the ESI feature in particular is something we want to take advantage of
extensively.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Where does Varnish typically reside in the network
architecture? I would imagine in a scenario in which we would be using ESI, we
would want Varnish in front of the application load balancers. In this way, Varnish
would be the primary page assembler. We would likely run an HA setup for fault
tolerance.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>We were also considering if Varnish could be used much
farther downstream – in between the load balancer and the application. We
thought is might provide for more fault tolerance, but it seems the disadvantage
would be that there would be a separate cached copy in each redundant varnish
instance, and with ESI secondary requests would be made back out to the same
web server potentially, setting up a feed back loop that could cause problems.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Thanks for your responses in advance.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>August<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Tahoma><span style='font-size:8.0pt;
font-family:Tahoma'>August Gresens<br>
<font color=black><span style='color:black'>Director of Technology, eScholastic</span></font></span></font><font
color=black><span style='color:black'><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 color=black face=Tahoma><span style='font-size:
8.0pt;font-family:Tahoma;color:black'>Scholastic Inc.<br>
557 Broadway, <st1:place w:st="on"><st1:City w:st="on">NY</st1:City>, <st1:State
w:st="on">NY</st1:State> <st1:PostalCode w:st="on">10012</st1:PostalCode></st1:place></span></font><font
color=black><span style='color:black'><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 color=black face=Tahoma><span style='font-size:
8.0pt;font-family:Tahoma;color:black'>Email :: <a
href="mailto:agresens@scholastic.com"><font color=black><span style='color:
black'>agresens@scholastic.com</span></font></a><br>
Phone :: 917 363 3662</span></font><font color=black><span
style='color:black'><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
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