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From Chris Lohfink <clohf...@blackbirdit.com>
Subject Re: What does the "rate" signify for latency in the JMX Metrics?
Date Thu, 15 May 2014 20:36:33 GMT
> What does the rate signify in this context?  For example, given the OneMinuteRate of 
675.7673129014964 and the unit of "seconds"--what is this measuring?

means that there were 675 write requests per second over the last one minute. 

As Other Chris (tm) mentioned this is exp decaying reservoir.

         Uses an exponentially decaying sample of 1028 elements, which offers a 99.9% confidence
         level with a 5% margin of error assuming a normal distribution, and an alpha factor
of 0.015
 	 which heavily biases the sample to the past 5 minutes of measurements.

http://dimacs.rutgers.edu/~graham/pubs/papers/fwddecay.pdf

---
Chris Lohfink

On May 7, 2014, at 1:00 PM, Chris Burroughs <chris.burroughs@gmail.com> wrote:

> They are exponential decaying moving averages (like Unix load averages) of the number
of events per unit of time.
> 
> http://wiki.apache.org/cassandra/Metrics might help
> 
> On 04/17/2014 06:06 PM, Redmumba wrote:
>> Good afternoon,
>> 
>> I'm attempting to integrate the metrics generated via JMX into our internal
>> framework; however, the information for several of the metrics includes a
>> One/Five/Fifteen-minute "rate", with the RateUnit in "SECONDS".  For
>> example:
>> 
>> $>get -b
>>> org.apache.cassandra.metrics:name=Latency,scope=Write,type=ClientRequest *
>>> #mbean =
>>> org.apache.cassandra.metrics:name=Latency,scope=Write,type=ClientRequest:
>>> LatencyUnit = MICROSECONDS;
>>> 
>>> EventType = calls;
>>> 
>>> RateUnit = SECONDS;
>>> 
>>> MeanRate = 383.6944837362387;
>>> 
>>> FifteenMinuteRate = 868.8420188648543;
>>> 
>>> FiveMinuteRate = 817.5239450236011;
>>> 
>>> OneMinuteRate = 675.7673129014964;
>>> 
>>> Max = 498867.0;
>>> 
>>> Count = 31257426;
>>> 
>>> Min = 52.0;
>>> 
>>> 50thPercentile = 926.0;
>>> 
>>> Mean = 1063.114029159023;
>>> 
>>> StdDev = 1638.1542477604232;
>>> 
>>> 75thPercentile = 1064.75;
>>> 
>>> 95thPercentile = 1304.55;
>>> 
>>> 98thPercentile = 1504.3999999999992;
>>> 
>>> 99thPercentile = 2307.3500000000104;
>>> 
>>> 999thPercentile = 10491.850000000002;
>>> 
>> 
>> What does the rate signify in this context?  For example, given the
>> OneMinuteRate of  675.7673129014964 and the unit of "seconds"--what is this
>> measuring?  Is this the rate of which metrics are submitted? i.e., there
>> were an average of (676 * 60 seconds) metrics submitted over the last
>> minute?
>> 
>> Thanks!
>> 
> 


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