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[Question #158830]: MAX_CREATES_PER_MINUTE discarding metrics

 

New question #158830 on Graphite:
https://answers.launchpad.net/graphite/+question/158830

I was performance testing Graphite when I discovered that only a small number of the metrics I was sending to Graphite were ever being written to disk.  I found this bit of relevant code in writer.py:

elif createCount >= settings.MAX_CREATES_PER_MINUTE:
        # dropping queued up datapoints for new metrics prevents filling up the entire cache
        # when a bunch of new metrics are received.
        try:
          MetricCache.pop(metric)
        except KeyError:
          pass

So am I correct that Graphite discards metrics in the queue once it hits MAX_CREATES_PER_MINUTE?  I was very surprised to see this behavior.  The comments in carbon.conf don't mention that setting this low will lose data, I thought it would just take longer to create new whisper files.  Is there a way to make graphite non-lossy other than setting this very high?  We've had performance problems and so I was hoping to slow disk writes in order to increase Graphite's ability to receive metrics quickly, but it appears this is not the way to do that.  Can anyone verify I'm understanding this right?

Thanks!

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