Histogram has count data but not sum

[Manish G]

Hi All,

I have added histogram to code following here.

But I observe that on prometheus board I get only count metrics, not sum. Metrics itself is missing.

I have used classes:

com.codahale.metrics.Histogram
org.apache.flink.dropwizard.metrics.DropwizardHistogramWrapper

What do I miss here?

[Chesnay Schepler]

What exactly do you mean with "count metrics" and "sum"?

Given a Histogram H, you should see:

- one time series named <scope>H_count

- one time series named <scope>H, with various labels for the different quantiles.

What do you see in Prometheus, and what do you consider to be missing?

On 1/13/2021 4:10 PM, Manish G wrote:

Hi All,

I have added histogram to code following here.

But I observe that on prometheus board I get only count metrics, not sum. Metrics itself is missing.

I have used classes:

com.codahale.metrics.Histogram
org.apache.flink.dropwizard.metrics.DropwizardHistogramWrapper

What do I miss here?

[Manish G]

So I an following this link too, to calculate average request duration. As per this page, histogram metrics has _count, _sum data. Though it is prometheus histogram, I expected flink histogram too would provide me same.

On Wed, Jan 13, 2021 at 8:50 PM Chesnay Schepler <[hidden email]> wrote:

What exactly do you mean with "count metrics" and "sum"?

Given a Histogram H, you should see:

- one time series named <scope>H_count

- one time series named <scope>H, with various labels for the different quantiles.

What do you see in Prometheus, and what do you consider to be missing?

On 1/13/2021 4:10 PM, Manish G wrote:

Hi All,

I have added histogram to code following here.

But I observe that on prometheus board I get only count metrics, not sum. Metrics itself is missing.

I have used classes:

com.codahale.metrics.Histogram
org.apache.flink.dropwizard.metrics.DropwizardHistogramWrapper

What do I miss here?

[Chesnay Schepler]

Flink Histograms are exposed as Summaries, since the quantiles are computed on the client-side (i.e., Flink side)

Flink Histograms cannot provide _sum data because we simply do not compute it, IIRC because Dropwizard Histograms also don't compute a sum and they are the only implementations to exist.

On 1/13/2021 4:24 PM, Manish G wrote:

So I an following this link too, to calculate average request duration. As per this page, histogram metrics has _count, _sum data. Though it is prometheus histogram, I expected flink histogram too would provide me same.

On Wed, Jan 13, 2021 at 8:50 PM Chesnay Schepler <[hidden email]> wrote:

What exactly do you mean with "count metrics" and "sum"?

Given a Histogram H, you should see:

- one time series named <scope>H_count

- one time series named <scope>H, with various labels for the different quantiles.

What do you see in Prometheus, and what do you consider to be missing?

On 1/13/2021 4:10 PM, Manish G wrote:

Hi All,

I have added histogram to code following here.

But I observe that on prometheus board I get only count metrics, not sum. Metrics itself is missing.

I have used classes:

com.codahale.metrics.Histogram
org.apache.flink.dropwizard.metrics.DropwizardHistogramWrapper

What do I miss here?