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I have some custom munin graphs that measure an aspect of our sales in our webapp. So I measure "Number of sales so far today". The graph goes up and then reset to 0 at midnight. This is what I want. It works well for the "by day", 5 minute one. Munin by default makes 3 extra graphs showing a longer term view, it has a "by week", "by month" and "by year" view which is based (AFAIK) on the combined data.

However the default seems to be an average of the values, so the total number of sales for a day is an average. I'd much much rather if the combined weekly/monthly/yearly data is based on the maximum/largest for that period. So rather than averaging, it'll 'maximise'?

I'd prefer if this can be done without losing our existing data, however I'm willing to lose the existing data/graphs if that's what's needed.

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I too would like to have a better solution to this. Currently I use an additional 'daily max' plugin for those type of metrics, which just spits out the maximum value from the day before. This makes the week/month/year graphs meaningful, but it's a bit of a hack, requires your previous max value to be cached somewhere etc. – The Almighty Bob Dec 18 '13 at 13:24

I would love to know this answer too.

I suspect it would be useful to review what RRDTool can do (this looks possibly useful: ) and then hack munin? Or perhaps the CDEF function will let you do this: has some useful info and a link to a tutorial.

You could also try asking your question on the munin-users mailing list. I looked through the plugin exchange and didn't see anything that seemed appropriate.

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I might be wrong, but isn't then Munin/RRDtool the wrong tool for your needs? As far as I know RRDtool is exactly meant to keep fewer data samples the further away the date is. (sorry no native english speaker, hope you understand what I mean).

To clarify, even if you could select the maximal value, you might not be sure that this was the absolute value, as not all data samples were kept in the rrd files.

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