Ben wrote: > it generates blank graph. > > > Where i did mistake, please provide your feedback.
Usual problem is that you haven't supplied enough data - either for long enough or frequently enough to 'fill' any buckets. In your case, you've used 120s (2min) buckets, so you need to provide data that will span a 2 minute period which starts/ends on an integer multiple of 2 minutes since unix epoch (midnight 1st Jan 1970) - which means periods from 0 to 2 minutes past the hour, 2 to 4 minutes past, and so on. However, you've specified a heartbeat of 0, which means that 0 seconds after each update, the data is deemed to be unknown - you should be able to see the problem there. The heartbeat is normally set to somewhat longer than your normal update intervals so that a variation in update times won't cause lost data - how long is dependent on your particular situation. > One confusion from me : RRA stands for Round Robin Archive, so when >we should use MAX/MIN/AVERAGE/LAST with RRA? Please provide some example. The consolidations do what they say. When the primary data points are consolidated, the specified function is applied. In your test case, you've used 1 primary point per consolidated point so there is no difference (they are null operations). However it's more normal to consolidate multiple primary points into one longer consolidated point - eg consolidating 12off 5 minutes periods into 1off 60minute (1hour) period. Take the following values : 1, 2, 3, 4, 10 If you consolidate them to one data point then : Average gives you 4 (1 + 2 + 3 + 4 + 10 = 20, 20/5 = 4) Minimum gives you 1 - the smallest of all the values Maximum gives you 10 - the largest of all the values Last will give you 10 - the last value Note that RRA relates to how the data is stored, not to how it is calculated. If you are storing (say) 100 samples, then you'd have 100 buckets. You'd put a value in bucket 0, then bucket 1, then bucket 2, and so on until all buckets are filled. Then after filling bucket 99 you loop back and overwrite bucket 0, then 1, and so on. The data size is fixed, and there is no overhead in extending the file, clearing old data, etc, etc. All it needs is a data structure to store the data, and some pointers to keep track of where you are at any point. There are some good tutorials at http://www.vandenbogaerdt.nl/rrdtool/ In particular, see the one on consolidation and normalisation. -- Simon Hobson Visit http://www.magpiesnestpublishing.co.uk/ for books by acclaimed author Gladys Hobson. Novels - poetry - short stories - ideal as Christmas stocking fillers. Some available as e-books. _______________________________________________ rrd-users mailing list [email protected] https://lists.oetiker.ch/cgi-bin/listinfo/rrd-users
