[tor-bugs] #13274 [Globe]: mean uptime (monthly) versus mean uptime (weekly) -one has too big rounding errors

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#13274: mean uptime (monthly) versus mean uptime (weekly) -one has too big rounding
errors
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     Reporter:  toralf  |      Owner:  rndm
         Type:  defect  |     Status:  new
     Priority:  minor   |  Milestone:
    Component:  Globe   |    Version:
   Resolution:          |   Keywords:
Actual Points:          |  Parent ID:
       Points:          |
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Comment (by karsten):

 Yup, this is a bug in Globe.  When it calculates mean uptime it doesn't
 distinguish between 0 ("node is down") and null ("no data about uptime or
 downtime").  Here's what Onionoo returns for this relay's uptime in the
 past week:

 {{{
 "first": "2014-09-22 09:30:00",
 "last": "2014-09-29 09:30:00",
 "interval": 3600,
 "factor": 0.001001001001001001,
 "count": 169,
 "values": [
     999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999,
     999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999,
     999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999,
     999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999,
     999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999,
     999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999,
     999, 999, 999, 999, 999, 999, 999, null, 999, 999, 999, 999, 999,
     999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999,
     999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999,
     999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999,
     999, 999, 999, 999, 999, null, 999, 999, 999, 999, 999, 999, 999,
     999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999,
     999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999, 999
 ]
 }}}

 Globe tells me mean uptime is 98.82%.  That's 167 times value 999 times
 factor 0.001001001001001001 divided by '''169''' values.

 What it should calculate is 167 times value 999 times factor
 0.001001001001001001 divided by '''167''' values, which is 100%.

 By the way, there's a related bug in the graphs which shouldn't drop to
 zero in case of null values but which should stop drawing the line and
 resume drawing at the next non-null value.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/13274#comment:1>
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