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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='color:#1F497D'>I tried using a prefetch trigger at 90% instead of 10% (intentionally inefficient) and a cache-min-ttl of 5400 so that an hourly scan is guaranteed to find a cached entry from the last scan and will also reset it’s TTL back to 5400 by forcing a new iteration.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>If I do a new namebench run, I still get a 150ms+ avg response time and I see several responses that have a TTL of 5400 meaning they were cachemisses. <o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><table class=MsoNormalTable border=0 cellspacing=0 cellpadding=0 width=2042 style='width:1225.35pt;margin-left:-.75pt;border-collapse:collapse'><tr style='height:.2in'><td width=248 nowrap valign=bottom style='width:149.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal><span style='color:black'>blog.sina.com.cn.<o:p></o:p></span></p></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal><span style='color:black'>A<o:p></o:p></span></p></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal align=right style='text-align:right'><span style='color:black'>814.8959<o:p></o:p></span></p></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal align=right style='text-align:right'><span style='color:black'>5400<o:p></o:p></span></p></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal align=right style='text-align:right'><span style='color:black'>2<o:p></o:p></span></p></td><td width=1179 nowrap colspan=4 valign=bottom style='width:707.5pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal><span style='color:black'>blogx.sina.com.cn. -> 218.30.115.254<o:p></o:p></span></p></td><td width=295 nowrap valign=bottom style='width:176.85pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td></tr><tr style='height:.2in'><td width=248 nowrap valign=bottom style='width:149.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.9pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.9pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.85pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.85pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.85pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td></tr><tr style='height:.2in'><td width=248 nowrap valign=bottom style='width:149.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal><span style='color:black'>www.utorrent.com.<o:p></o:p></span></p></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal><span style='color:black'>A<o:p></o:p></span></p></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal align=right style='text-align:right'><span style='color:black'>203.908<o:p></o:p></span></p></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal align=right style='text-align:right'><span style='color:black'>5400<o:p></o:p></span></p></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal align=right style='text-align:right'><span style='color:black'>1<o:p></o:p></span></p></td><td width=590 nowrap colspan=2 valign=bottom style='width:353.8pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal><span style='color:black'>67.215.233.130<o:p></o:p></span></p></td><td width=295 nowrap valign=bottom style='width:176.85pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.85pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.85pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td></tr><tr style='height:.2in'><td width=248 nowrap valign=bottom style='width:149.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.9pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.9pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.85pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.85pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.85pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td></tr><tr style='height:.2in'><td width=248 nowrap valign=bottom style='width:149.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal><span style='color:black'>in.youtube.com.<o:p></o:p></span></p></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal><span style='color:black'>A<o:p></o:p></span></p></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal align=right style='text-align:right'><span style='color:black'>29.46731<o:p></o:p></span></p></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal align=right style='text-align:right'><span style='color:black'>2982<o:p></o:p></span></p></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal align=right style='text-align:right'><span style='color:black'>2<o:p></o:p></span></p></td><td width=1474 nowrap colspan=5 valign=bottom style='width:884.35pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal><span style='color:black'>youtube-ui.l.google.com. -> 74.125.224.46, 74.125.224.32, 74.125.224.33, 74.125.224.34, 74.125.224.35, 74.125.224.36, 74.125.224.37, 74.125.224.38, 74.125.224.39, 74.125.224.40, 74.125.224.41<o:p></o:p></span></p></td></tr><tr style='height:.2in'><td width=248 nowrap valign=bottom style='width:149.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.9pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.9pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.85pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.85pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.85pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td></tr><tr style='height:.2in'><td width=248 nowrap valign=bottom style='width:149.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal><span style='color:black'>search.mywebsearch.com.<o:p></o:p></span></p></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal><span style='color:black'>A<o:p></o:p></span></p></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal align=right style='text-align:right'><span style='color:black'>72.6796<o:p></o:p></span></p></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal align=right style='text-align:right'><span style='color:black'>2985<o:p></o:p></span></p></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal align=right style='text-align:right'><span style='color:black'>2<o:p></o:p></span></p></td><td width=1474 nowrap colspan=5 valign=bottom style='width:884.35pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal><span style='color:black'>www154.mywebsearch.com. -> 74.113.233.48<o:p></o:p></span></p></td></tr><tr style='height:.2in'><td width=248 nowrap valign=bottom style='width:149.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.9pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.9pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.85pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.85pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.85pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td></tr><tr style='height:.2in'><td width=248 nowrap valign=bottom style='width:149.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal><span style='color:black'>wenwen.soso.com.<o:p></o:p></span></p></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal><span style='color:black'>A<o:p></o:p></span></p></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal align=right style='text-align:right'><span style='color:black'>296.7475<o:p></o:p></span></p></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal align=right style='text-align:right'><span style='color:black'>5236<o:p></o:p></span></p></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal align=right style='text-align:right'><span style='color:black'>1<o:p></o:p></span></p></td><td width=590 nowrap colspan=2 valign=bottom style='width:353.8pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal><span style='color:black'>202.55.10.153<o:p></o:p></span></p></td><td width=295 nowrap valign=bottom style='width:176.85pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.85pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.85pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td></tr><tr style='height:.2in'><td width=248 nowrap valign=bottom style='width:149.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.9pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.9pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.85pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.85pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.85pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td></tr><tr style='height:.2in'><td width=248 nowrap valign=bottom style='width:149.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal><span style='color:black'>www.uploading.com.<o:p></o:p></span></p></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal><span style='color:black'>A<o:p></o:p></span></p></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal align=right style='text-align:right'><span style='color:black'>26.0509<o:p></o:p></span></p></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal align=right style='text-align:right'><span style='color:black'>3007<o:p></o:p></span></p></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal align=right style='text-align:right'><span style='color:black'>1<o:p></o:p></span></p></td><td width=590 nowrap colspan=2 valign=bottom style='width:353.8pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal><span style='color:black'>195.191.207.40<o:p></o:p></span></p></td><td width=295 nowrap valign=bottom style='width:176.85pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.85pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.85pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td></tr><tr style='height:.2in'><td width=248 nowrap valign=bottom style='width:149.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.9pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.9pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.85pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.85pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td><td width=295 nowrap valign=bottom style='width:176.85pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'></td></tr><tr style='height:.2in'><td width=248 nowrap valign=bottom style='width:149.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal><span style='color:black'>www.ebay.com.<o:p></o:p></span></p></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal><span style='color:black'>A<o:p></o:p></span></p></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal align=right style='text-align:right'><span style='color:black'>31.4418<o:p></o:p></span></p></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal align=right style='text-align:right'><span style='color:black'>5400<o:p></o:p></span></p></td><td width=80 nowrap valign=bottom style='width:48.0pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal align=right style='text-align:right'><span style='color:black'>1<o:p></o:p></span></p></td><td width=1474 nowrap colspan=5 valign=bottom style='width:884.35pt;padding:0in 5.4pt 0in 5.4pt;height:.2in'><p class=MsoNormal><span style='color:black'>66.135.200.161, 66.135.200.181, 66.135.210.61, 66.135.210.181, 66.211.181.161, 66.211.181.181<o:p></o:p></span></p></td></tr></table><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>So this is appearing like unexpected behavior to me: If <a href="http://www.utorrent.com">www.utorrent.com</a> was scanned less than an hour ago and was supposed to be cached for 5400 seconds, why would a random scan like the one above find it flushed out of the cache (5400 TTL) and requiring an iteration (203.9 msecs response time)?<o:p></o:p></span></p><p class=MsoNormal><a name="_MailEndCompose"><span style='color:#1F497D'><o:p> </o:p></span></a></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> 1phon3apps@googlegroups.com [mailto:1phon3apps@googlegroups.com] <b>On Behalf Of </b>vinay3@justemail.net<br><b>Sent:</b> Friday, July 06, 2012 11:24 PM<br><b>To:</b> unbound-users@unbound.net<br><b>Subject:</b> Improve avg response times<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I am using an amazon large EC2 instance (4ECUs, 2 cores) for my unbound configured as below. I am seeing a 150ms+ average response time as reported by namebench Alexa 2K result. In order to reduce my lookup times, I am running an hourly scan of these 35K sites (from namebench dat files) in order to give my clients a cached response whenever possible. On average, my cachemiss rate is 6% as shown below. My cache-ttl-min is 1 hour so these entries should be cached at all times. The cachemisses I am guessing are from sites my pythonmod looks up and responds to in a special way:<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>6.5Mbytes of free RAM<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>total.num.cachehits=3185<o:p></o:p></p><p class=MsoNormal>total.num.cachemiss=188<o:p></o:p></p><p class=MsoNormal>mem.cache.rrset=8319405<o:p></o:p></p><p class=MsoNormal>mem.cache.message=8729827<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>(forked configuration)<o:p></o:p></p><p class=MsoNormal>server:<o:p></o:p></p><p class=MsoNormal> #disable chroot as it caused several issues with python's PYTHONHOME vars<o:p></o:p></p><p class=MsoNormal> chroot: ""<o:p></o:p></p><p class=MsoNormal> verbosity: 0<o:p></o:p></p><p class=MsoNormal> # set to num of cores or cpus<o:p></o:p></p><p class=MsoNormal><b> num-threads: 2<o:p></o:p></b></p><p class=MsoNormal> ##slabs <o:p></o:p></p><p class=MsoNormal> rrset-cache-slabs: 1<o:p></o:p></p><p class=MsoNormal> infra-cache-slabs: 1<o:p></o:p></p><p class=MsoNormal> key-cache-slabs: 1<o:p></o:p></p><p class=MsoNormal> msg-cache-slabs: 1<o:p></o:p></p><p class=MsoNormal> ##cache sizes<o:p></o:p></p><p class=MsoNormal> msg-cache-size: 250m<o:p></o:p></p><p class=MsoNormal> #2X msg-cache-size<o:p></o:p></p><p class=MsoNormal> rrset-cache-size: 500m<o:p></o:p></p><p class=MsoNormal> outgoing-range: 950<o:p></o:p></p><p class=MsoNormal> #2X outgoing range<o:p></o:p></p><p class=MsoNormal> num-queries-per-thread: 512<o:p></o:p></p><p class=MsoNormal> # sudo sysctl -w net.core.rmem_max=8388608<o:p></o:p></p><p class=MsoNormal> so-rcvbuf: 8m<o:p></o:p></p><p class=MsoNormal> interface: 0.0.0.0<o:p></o:p></p><p class=MsoNormal> interface: ::0<o:p></o:p></p><p class=MsoNormal> port: 53<o:p></o:p></p><p class=MsoNormal> access-control: 0.0.0.0/0 allow<o:p></o:p></p><p class=MsoNormal> module-config: "python iterator"<o:p></o:p></p><p class=MsoNormal><b> prefetch: yes<o:p></o:p></b></p><p class=MsoNormal><b> cache-min-ttl: 3600<o:p></o:p></b></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>python:<o:p></o:p></p><p class=MsoNormal> python-script: "XYZ"<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>remote-control:<o:p></o:p></p><p class=MsoNormal> control-enable: yes<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>forward-zone:<o:p></o:p></p><p class=MsoNormal> name: "."<o:p></o:p></p><p class=MsoNormal> forward-addr: XYZ<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Question:<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Even with this setup, I am seeing most of the domains return a TTL of 3600 at the start of a random namebench which means they were iterated/recursed over instead of looked up from cache. This is causing a 150ms+ average response times for these 35K sites. It’s the exact same 35K sites being scanned by namebench – why aren’t these looked up from the cache instead of being iterated over? Are these sites not cached for a full 3600 seconds? <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>With prefetch, cache-min-ttl of 1hour, why isn’t an hourly scan of these 35K sites populating my cache and giving me a <50ms response time on average?<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>With the same setup, if I take 500 sites and run namebench back to back for these fixed 500 sites, my average response time starts approaching 40-50ms which is where I am trying to be with the 35K sites. <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Where am I going wrong and how can debug and fix this issue?<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Vinay.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>