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Miscellaneous Code

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DNSCache Stats

I graph my dnscache movement with MRTG. My /service/dnscache/log/run file contains:

exec setuidgid logging multilog t s10485760 n3 \
	'-* cached *' '-* rr *' '-* tx *' /var/log/dnscache \
	'-*' '+* stats *' =/var/log/dnscache/stats.log

This puts rotates three 1MB log files that contain no RR or TX records (my preference). The last line is the important one; it puts the most recent 'stats' line in the stats.log file. This is used by the script below:

exec head -n1 /var/log/dnscache/stats.log \
	| awk '{ print $3"\n"$4"\n0\n0" }'

This script (I have it as /usr/bin/mrtg-dnscache.sh) outputs the query count and byte count in the way MRTG needs them for use with the following snippet from my mrtg.cfg:

Target[dnscache]: `/usr/bin/mrtg-dnscache.sh`
Title[dnscache]: dnscache movement
PageTop[dnscache]: <H1>dnscache</H1>
ShortLegend[dnscache]: Bps
MaxBytes[dnscache]: 10000000
YLegend[dnscache]: Bytes / Queries per second
Legend1[dnscache]: Queries per second
Legend2[dnscache]: Bytes per second
Legend3[dnscache]: Max Queries/sec
Legend4[dnscache]: Max Bytes/sec
LegendI[dnscache]: Queries/sec 
LegendO[dnscache]: Bytes/sec 
Options[dnscache]: growright,noinfo
Withpeak[dnscache]: dm

With the above, you should get a nice graph showing how much data and how many queries are passing through your dnscache installation like this:
Sample MRTG output