Question #83274 on Graphite changed: https://answers.launchpad.net/graphite/+question/83274
chrismd posted a new comment: Glad to help Steve but I'd like to offer a tiny bit more advice if thats alright. 20 minutes is obviously way too long for a request like this to take, and I don't even know the specifics, it just *sounds* bad! So I'll offer up some thoughts on what might be causing this. So if you have 3,048 different metrics involved in your request, then yes that will correspond to 3,048 different whisper files. If your data is stored with minutely precision and you're using from=-1d then you are extracting 1,440 data points per metric (one for each minute in the past 24 hours). Each data point is 12 bytes on disk, so your entire request requires graphite to read approximately 50 megs of data off the disk (12 bytes * 1440 * 3048). That's not a huge amount but keep in mind that since it is spread across 3,048 different files your disk will be doing a lot of seeking so that may be the cause of the problem. Again this estimate assumes your data is stored with minutely precision which may not be the case, but in any case I think the following recommendation may help. I assume this type of request is a common thing you will need to do (otherwise waiting 20 minutes probably wouldn't be a big deal). As a general rule of thumb I try to optimize the data I send to graphite for its common use cases. For example, a long time ago I had about 100 or so performance metrics that I almost always viewed in a single aggregate graph and seldom in isolation. So to make my big graph render quicker I started pre-calculating the aggregate values it displayed and sent those directly to graphite in addition to the individual metrics. This meant that when I requested the big aggregate graph only a single database file was involved. Granted this particular technique may not apply in your use case, but I would bet that some variant of it could help. 3,048 different metrics (multipled by however many datapoints you store for each per day) is a lot of data points so I assume you are doing some sort of post-processing on this data to summarize it after you retrieve it. My recommendation would be to try and think of a way to send some sort of pre-calculated values into graphite that would make your computation involve less data points later on. I hope that helps. -- You received this question notification because you are a member of graphite-dev, which is an answer contact for Graphite. _______________________________________________ Mailing list: https://launchpad.net/~graphite-dev Post to : [email protected] Unsubscribe : https://launchpad.net/~graphite-dev More help : https://help.launchpad.net/ListHelp
