what's the meaning of latency indicator reported by flink metrics through prometheus?

[varuy322]

Hi there,

I have integrated kafka with flink1.5, also with the help of prometheus and
Granada to display metrics of flink 1.5,
now i get three indicator about latency as below:
1)flink_taskmanager_job_latency_source_id_source_subtask_index_operator_id_operator_subtask_index_latency(short
for latency)
2)flink_taskmanager_job_latency_source_id_source_subtask_index_operator_id_operator_subtask_index_latency_count(short
for latency_count)
3)flink_taskmanager_job_latency_source_id_source_subtask_index_operator_id_operator_subtask_index_latency_sum(short
for latency_sum)

it seems 1) to be the latency value of one real subtask,
for 2),latency_count always equal to one const, in my example the value is
128,
for 3),latency_sum always equal to zero.

could you tell me what's the meaning of 2) and 3)?

Best regards & Thanks.
Rui, Wang

<http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/file/t1661/latency_metric.png>



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[Chesnay Schepler]

1) correct
2) is the number of measurements; due to the random distribution of
latency markers this value can be surprisingly low depending on the
latency marker interval
3) I don't know, but it isn't exposed by Flink.

On 08.10.2018 10:17, varuy322 wrote:

> Hi there,
>
> I have integrated kafka with flink1.5, also with the help of prometheus and
> Granada to display metrics of flink 1.5,
> now i get three indicator about latency as below:
> 1)flink_taskmanager_job_latency_source_id_source_subtask_index_operator_id_operator_subtask_index_latency(short
> for latency)
> 2)flink_taskmanager_job_latency_source_id_source_subtask_index_operator_id_operator_subtask_index_latency_count(short
> for latency_count)
> 3)flink_taskmanager_job_latency_source_id_source_subtask_index_operator_id_operator_subtask_index_latency_sum(short
> for latency_sum)
>
> it seems 1) to be the latency value of one real subtask,
> for 2),latency_count always equal to one const, in my example the value is
> 128,
> for 3),latency_sum always equal to zero.
>
> could you tell me what's the meaning of 2) and 3)?
>
> Best regards & Thanks.
> Rui, Wang
>
> <http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/file/t1661/latency_metric.png>
>
>
>
> -----
> stay hungry, stay foolish.
> --
> Sent from: http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/
>