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</o:shapelayout></xml><![endif]--></head><body lang=EN-IE link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Great, thanks very much!<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>-Connor</span><span style='font-size:10.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> Stig Bakken [mailto:stig@zedge.net] <br><b>Sent:</b> 02 November 2011 10:15<br><b>To:</b> Connor Walls<br><b>Cc:</b> varnish-misc@varnish-cache.org<br><b>Subject:</b> Re: Question about varnishstat and hitrate<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Varnish's cache hit rate is a percentage of hits among requests that went through vcl_lookup, not all requests.<br><br> - Stig<o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>On Wed, Nov 2, 2011 at 10:53 AM, Connor Walls <<a href="mailto:connor.walls@skillpages.com">connor.walls@skillpages.com</a>> wrote:<o:p></o:p></p><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:11.0pt;color:#1F497D'>Hi,</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:11.0pt;color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:11.0pt;color:#1F497D'>I had a question about the numbers generated in varnishstat. Looking at the current hitrate average for one of our boxes is giving an average of 0.4833 for the last 1000 requests, and the hitrate is in and around this number on all of our varnish boxes. We are also recording the output of varnishlog to a file, including a “X-Cache” header, as per this article: <a href="https://www.varnish-cache.org/trac/wiki/VCLExampleHitMissHeader" target="_blank">https://www.varnish-cache.org/trac/wiki/VCLExampleHitMissHeader</a>. Now, what I’m curious about is whenever I look at the responses that have been logged, <5% of them are being served from the cache, which is at odds with the 48% that varnishstat is reporting. Is the hitrate average only taking into account pages that are passed, and not pages that are fetched? Why is there such a discrepancy between the two values?</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:11.0pt;color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:11.0pt;color:#1F497D'>Here’s a sample output from varnishstat, if it helps explain things better.</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:11.0pt;color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'>4+18:04:37 domU-12-31-39-10-74-A8</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'>Hitrate ratio: 10 100 1000</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'>Hitrate avg: 0.3646 0.4249 0.4833</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 1528600 3.96 3.72 Client connections accepted</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 10346326 23.77 25.19 Client requests received</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 5244804 0.99 12.77 Cache hits</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 9509 0.00 0.02 Cache hits for pass</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 147772 0.00 0.36 Cache misses</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 22490 0.00 0.05 Backend conn. success</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 4731723 21.79 11.52 Backend conn. reuses</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 12459 0.00 0.03 Backend conn. was closed</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 4744236 19.81 11.55 Backend conn. recycles</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 9505 0.00 0.02 Fetch head</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 4727908 20.80 11.51 Fetch with Length</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 1751 0.00 0.00 Fetch chunked</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 422 . . N struct sess_mem</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 96 . . N struct sess</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 4104 . . N struct object</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 4148 . . N struct objectcore</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 4115 . . N struct objecthead</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 48 . . N struct vbe_conn</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 53 . . N worker threads</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 7788 0.00 0.02 N worker threads created</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 0 0.00 0.00 N queued work requests</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 32999 0.00 0.08 N overflowed work requests</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 1 . . N backends</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 136098 . . N expired objects</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 397731 . . N LRU moved objects</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 8861590 17.82 21.58 Objects sent with write</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 1528600 3.96 3.72 Total Sessions</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 10346326 23.77 25.19 Total Requests</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 4600511 20.80 11.20 Total pass</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 4744331 20.80 11.55 Total fetch</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> <a href="tel:5613543692" target="_blank">5613543692</a> 14549.86 13669.00 Total header bytes</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'>50230527274 64650.96 122311.52 Total body bytes</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 398864 1.98 0.97 Session Closed</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 1 0.00 0.00 Session Pipeline</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 9989106 21.79 24.32 Session Linger</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 4717398 17.82 11.49 Session herd</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 731094771 2065.68 1780.22 SHM records</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 29558086 95.06 71.97 SHM writes</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 14131 0.00 0.03 SHM MTX contention</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 353 0.00 0.00 SHM cycles through buffer</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 3518804 16.83 8.57 SMA allocator requests</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 8184 . . SMA outstanding allocations</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 46354320 . . SMA outstanding bytes</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'>12051521527 . . SMA bytes allocated</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'>12005167207 . . SMA bytes free</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 357190 1.98 0.87 SMS allocator requests</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 0 . . SMS outstanding allocations</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 0 . . SMS outstanding bytes</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 135529138 . . SMS bytes allocated</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 135529138 . . SMS bytes freed</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 4744578 20.80 11.55 Backend requests made</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 1 0.00 0.00 N vcl total</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 1 0.00 0.00 N vcl available</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 240460 . . N total active purges</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 353239 1.98 0.86 N new purges added</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 112779 0.99 0.27 N old purges deleted</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 510753 0.99 1.24 N objects tested</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 32284561 412.94 78.61 N regexps tested against</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;margin-left:36.0pt'><span style='font-size:10.0pt;font-family:Consolas'> 155686 0.99 0.38 N duplicate purges removed</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:11.0pt;color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:11.0pt;color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:11.0pt;color:#1F497D'>Thanks for any help,</span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='font-size:11.0pt;color:#1F497D'>Connor Walls</span><span style='font-size:10.0pt;color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p></div></div><p class=MsoNormal><br>_______________________________________________<br>varnish-misc mailing list<br><a href="mailto:varnish-misc@varnish-cache.org">varnish-misc@varnish-cache.org</a><br><a href="https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc" target="_blank">https://www.varnish-cache.org/lists/mailman/listinfo/varnish-misc</a><o:p></o:p></p></div><p class=MsoNormal><br><br clear=all><o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p></div><p class=MsoNormal>-- <br>Stig Bakken<br>CTO, Zedge.net - free your phone!<o:p></o:p></p></div></div></body></html>