# what is sum of ceilometer instance meter?

I am using Newton version Openstack Ceilometer without gnocchi. I query some statistics of instance meter from the Ceilometer like below, it returns all the aggregated data like avg, min, max, **sum**:

```
Statistics {u'count': 6, u'duration_start': u'2017-06-07T01:03:37.383127', u'min': 1.0, u'max': 1.0, u'duration_end': u'2017-06-07T01:53:37.086380', u'period': 0, u'groupby': {u'resource_id': u'288edd7d-bbc4-4165-bdf0-ca36837d6b2d'}, u'period_end': u'2017-06-07T01:53:37.086380', u'duration': 2999.703253, u'period_start': u'2017-06-07T01:03:37.383127', u'avg': 1.0, u'sum': 6.0, u'unit': u'instance'}
```

are these aggregation data correct?
what does the **sum** means here? how does it make sense ?

or

different meters use different aggregation method?

You have 6 samples, on average an instance per sample. It looks like the sum is just - the sum of it. I would think this is done no matter what meter you look at.

Does it make sense? At first I thought no, but you could bill your clients based on that sum, for example.

Great, thanks for your answer, I see it now. Can I ask another question about billing, I am looking at billing project (cloudkitty), I got a question about cloudkitty as well. Probably I need to open another question https://ask.openstack.org/en/question...

I am not the righ person to help with billing. Good that you created another thread.