<p>Try caused recursion / non authorative.</p>
<p><blockquote type="cite">On Feb 23, 2010 3:47 PM, "Timothy Holtzen" <<a href="mailto:tah@nebrwesleyan.edu">tah@nebrwesleyan.edu</a>> wrote:<br><br>I have seen references out there about cache hit rates of 50-70% being<br>
normal. However I'm confused as to how to measure/calculate hit ratio?<br>
I can't seem to find any good references on how to find it. The only<br>
thing I've been able to find is to do<br>
<br>
("responses sent") - ("queries caused recursion")<br>
<br>
but this would include queries for local authoritative zones. In our<br>
particular case if I divide by the total number of queries I end up with<br>
a number around 66%. Is this the correct way? In our particular case I<br>
suspect that the majority of those responses are for local authoritative<br>
zones. Wouldn't a more accurate way to measure cache performance be to<br>
take<br>
<br>
("non authoritative answer")-("queries caused recursion")/Total Queries?<br>
<br>
In our case calculating this way would yield a number closer to 13%<br>
which looks low when compared to the "normal" range listed above. How<br>
are others calculating hit rate/ratio and what do you tend to see as<br>
"normal"? Obviously normal can vary wildly depending on configuration<br>
and what kind of queries a system receives. I'm just trying to get a<br>
handle on how our cache is performing and what I should expect. Cache<br>
hit rate seems to be an important metric when considering overall DNS<br>
performance.<br>
<br>
--<br>
Timothy A. Holtzen<br>
Campus Network Administrator<br>
Nebraska Wesleyan University<br>
<br>
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</blockquote></p>