Now that I tuned varnish a bit it's recommended to keep an eye on some stats. I made this little page so I could see the output of a few commands from the web panel without having to login.
<?php
if ( !isset( $include_path ) )
{
echo "invalid access";
exit( );
}
$vstat = shell_exec("varnishstat -1 | head -n 6");
$vhits = shell_exec("varnishtop -1 -i rxurl | head -n 10");
$vmiss = shell_exec("varnishtop -1 -i txurl | head -n 10");
$vnuke = shell_exec("varnishstat -1 | grep nuke ");
$vmem = shell_exec("ps aux | grep 'varnish' | awk '{print $6/1024 \" MB\";}'");
echo "<h3>Varnish Statistics</h3><br><br>";
echo "<h3>Varnishstat</h3><br><pre>".$vstat."</pre><br><br>";
echo "<h3>Top 10 Hits</h3><br><pre>".$vhits."</pre><br><br>";
echo "<h3>Top 10 Misses</h3><br><pre>".$vmiss."</pre><br><br>";
echo "<h3>Varnish Nukes</h3><br><pre>".$vnuke."</pre><br><br>";
echo "<h3>Varnish Memory</h3><br><pre>".$vmem."</pre><br><br>";
?>