understanding solr metrics

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understanding solr metrics

akhil dutt
Hi,
I'm trying to understand solr metrics and was looking at request/response
dispatch rate. I want to understand what meanRate signify. As per below
values, am I to suppose that  each request takes 300 seconds (1/ meanRate )?


org.eclipse.jetty.server.handler.DefaultHandler.dispatches:
{

   - count: 628,
   - meanRate: 0.003289067572916428,
   - 1minRate: 0.000005987072200468513,
   - 5minRate: 0.0011878359052365337,
   - 15minRate: 0.001259541736414636,
   - min_ms: 0,
   - max_ms: 755,
   - mean_ms: 43.5,
   - median_ms: 6,
   - stddev_ms: 40.5,
   - p75_ms: 84,
   - p95_ms: 84,
   - p99_ms: 84,
   - p999_ms: 84

},

Thanks,
Akhil
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Re: understanding solr metrics

Jason Gerlowski
Hi Akhil,

I'm not an expert on these metrics, but the way I've been reading them:

"meanRate" is a measure of how many requests come in per some unit of
time.  It has nothing to do with how long individual requests take.

"mean_ms" is the average time taken by requests (in milliseconds).

Hope that helps,

Jason

On Thu, Jan 2, 2020 at 9:13 AM akhil dutt <[hidden email]> wrote:

>
> Hi,
> I'm trying to understand solr metrics and was looking at request/response
> dispatch rate. I want to understand what meanRate signify. As per below
> values, am I to suppose that  each request takes 300 seconds (1/ meanRate )?
>
>
> org.eclipse.jetty.server.handler.DefaultHandler.dispatches:
> {
>
>    - count: 628,
>    - meanRate: 0.003289067572916428,
>    - 1minRate: 0.000005987072200468513,
>    - 5minRate: 0.0011878359052365337,
>    - 15minRate: 0.001259541736414636,
>    - min_ms: 0,
>    - max_ms: 755,
>    - mean_ms: 43.5,
>    - median_ms: 6,
>    - stddev_ms: 40.5,
>    - p75_ms: 84,
>    - p95_ms: 84,
>    - p99_ms: 84,
>    - p999_ms: 84
>
> },
>
> Thanks,
> Akhil
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Re: understanding solr metrics

Edward Ribeiro
Just adding some tidbits of info to Jason's answer: meanRate measures the
mean rate of event (requests) since the timer got created. See:
https://metrics.dropwizard.io/3.1.0/apidocs/com/codahale/metrics/Timer.html#getMeanRate--

Particularly, I don't think this metric is all that meaningful for
monitoring purposes. The others are much more useful, specially the p75,
p95, p_99 and p_9999 percentiles. The p95_ms, for example, states that 95%
of the requests took 84ms or less to complete. max_ms states that one or
more requests took up to 755 ms (outliers caused by network problems,
maybe, or slow queries that need to be investigated), but on average the
requests were completed upon 45 ms (with a standard deviation of 6, that is
an acceptable measure).

Best,
Edward


On Thu, Jan 2, 2020 at 11:42 AM Jason Gerlowski <[hidden email]>
wrote:

> Hi Akhil,
>
> I'm not an expert on these metrics, but the way I've been reading them:
>
> "meanRate" is a measure of how many requests come in per some unit of
> time.  It has nothing to do with how long individual requests take.
>
> "mean_ms" is the average time taken by requests (in milliseconds).
>
> Hope that helps,
>
> Jason
>
> On Thu, Jan 2, 2020 at 9:13 AM akhil dutt <[hidden email]> wrote:
> >
> > Hi,
> > I'm trying to understand solr metrics and was looking at request/response
> > dispatch rate. I want to understand what meanRate signify. As per below
> > values, am I to suppose that  each request takes 300 seconds (1/
> meanRate )?
> >
> >
> > org.eclipse.jetty.server.handler.DefaultHandler.dispatches:
> > {
> >
> >    - count: 628,
> >    - meanRate: 0.003289067572916428,
> >    - 1minRate: 0.000005987072200468513,
> >    - 5minRate: 0.0011878359052365337,
> >    - 15minRate: 0.001259541736414636,
> >    - min_ms: 0,
> >    - max_ms: 755,
> >    - mean_ms: 43.5,
> >    - median_ms: 6,
> >    - stddev_ms: 40.5,
> >    - p75_ms: 84,
> >    - p95_ms: 84,
> >    - p99_ms: 84,
> >    - p999_ms: 84
> >
> > },
> >
> > Thanks,
> > Akhil
>