dashboard: in-built variable for rate interval

In Grafana 7.2 `$__rate_interval` for Prometheus rate() metrics was
introduced [1]. This patch replaces user-specified `$rate_time_range`
variable with in-built `$__rate_interval`.

Since `$__rate_interval` should be enough to cover all rate cases, this
patch also removes all code traces of rate time range configuration.

1. https://grafana.com/blog/2020/09/28/new-in-grafana-7.2-__rate_interval-for-prometheus-rate-queries-that-just-work/

Closes #127

Author: DifferentialOrange

CHANGELOG.md

@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## Changed
 - Set default Prometheus job to `tarantool`
 - Set default InfluxDB measurement to `tarantool_http`
+- Use in-built `$__rate_interval` instead of user-defined `$rate_time_range`
 
 
 ## [1.3.0] - 2022-06-29

Makefile

@@ -1,5 +1,4 @@
 JOB ?= tarantool
-RATE_TIME_RANGE ?= 2m
 POLICY ?= autogen
 MEASUREMENT ?= tarantool_http
 OUTPUT_STATIC_DASHBOARD ?= dashboard.json
@@ -17,11 +16,9 @@ ifndef DATASOURCE
 		false
 endif
 	# JOB is optional, default is "tarantool"
-	# RATE_TIME_RANGE is optional, default is "2m"
 	jsonnet -J ./vendor -J . \
 		--ext-str DATASOURCE=${DATASOURCE} \
 		--ext-str JOB=${JOB} \
-		--ext-str RATE_TIME_RANGE=${RATE_TIME_RANGE} \
 		dashboard/build/prometheus/${DASHBOARD_BUILD_SOURCE} -o ${OUTPUT_STATIC_DASHBOARD}
 
 .PHONY: build-static-prometheus

README.md

@@ -51,8 +51,7 @@ Refer to dashboard [documentation page](https://www.tarantool.io/en/doc/latest/b
 
     You need to set the following variables for Prometheus datasource:
 
-    - `Job`,
-    - `Rate time range` (default valie is `2m`).
+    - `Job`.
 
     Datasource variables can be obtained from your datasource configuration.
     Variables for example monitoring cluster are described in [Monitoring cluster](#monitoring-cluster) section.
@@ -81,8 +80,7 @@ To set up an InfluxDB dashboard for monitoring example app, use the following va
 
 To set up an Prometheus dashboard for monitoring example app, use the following variables:
 
-- `Job`: `tarantool`;
-- `Rate time range`: `2m`.
+- `Job`: `tarantool`.
 
 ### Monitoring local app
 
@@ -128,7 +126,6 @@ Following targets are available:
 Variables for Prometheus targets:
 - `DATASOURCE`: name of a Prometheus data source;
 - `JOB` (optional, default `tarantool`): name of a Prometheus job collecting your application metrics;
-- `RATE_TIME_RANGE` (optional, default `2m`): rps computation rate time range;
 - `OUTPUT_STATIC_DASHBOARD` (optional, default `dashboard.json`): compiled dashboard file.
 
 Variables for InfluxDB targets:
@@ -277,7 +274,6 @@ You can add your own custom panels to the bottom of the template dashboard.
       datasource_type, # Target datasource type. Use grafana-dashboard/dashboard/variable.libsonnet to fill this value
       metric_name, # Target metric name to select
       job, # (Prometheus only) Prometheus metrics job. If you use default input variables, use grafana-dashboard/dashboard/variable.libsonnet to fill this value
-      rate_time_range, # (Prometheus only) Prometheus rps computation rate time range. If you use default input variables, use grafana-dashboard/dashboard/variable.libsonnet to fill this value
       policy, # (InfluxDB only) InfluxDB metrics policy. If you use default input variables, use grafana-dashboard/dashboard/variable.libsonnet to fill this value
       measurement, # (InfluxDB only) InfluxDB metrics measurement. If you use default input variables, use grafana-dashboard/dashboard/variable.libsonnet to fill this value
     )
@@ -292,7 +288,6 @@ You can add your own custom panels to the bottom of the template dashboard.
     ```jsonnet
     datasource=variable.datasource.prometheus,
     job=variable.prometheus.job,
-    rate_time_range=variable.prometheus.rate_time_range
     ```
     in your targets.
     
@@ -347,7 +342,6 @@ You can add your own custom panels to the bottom of the template dashboard.
       datasource_type=variable.datasource_type.prometheus,
       metric_name='my_component_load_metric_count',
       job=variable.prometheus.job,
-      rate_time_range=variable.prometheus.rate_time_range,
     ))
     ```
     Corresponding InfluxDB panels could be built with

dashboard/build/prometheus/dashboard.libsonnet

@@ -6,7 +6,6 @@ local variable = import 'dashboard/variable.libsonnet';
 dashboard_raw(
   datasource=variable.datasource.prometheus,
   job=variable.prometheus.job,
-  rate_time_range=variable.prometheus.rate_time_range
 ).addInput(
   name='DS_PROMETHEUS',
   label='Prometheus',
@@ -20,12 +19,6 @@ dashboard_raw(
   type='constant',
   value='tarantool',
   description='Prometheus Tarantool metrics job'
-).addInput(
-  name='PROMETHEUS_RATE_TIME_RANGE',
-  label='Rate time range',
-  type='constant',
-  value='2m',
-  description='Time range for computing rps graphs with rate(). At the very minimum it should be two times the scrape interval.'
 ).addTemplate(
   grafana.template.custom(
     name='job',
@@ -34,12 +27,4 @@ dashboard_raw(
     hide='variable',
     label='Prometheus job',
   )
-).addTemplate(
-  grafana.template.custom(
-    name='rate_time_range',
-    query='${PROMETHEUS_RATE_TIME_RANGE}',
-    current='${PROMETHEUS_RATE_TIME_RANGE}',
-    hide='variable',
-    label='rate() time range',
-  )
 )

dashboard/build/prometheus/dashboard_raw.libsonnet

@@ -4,7 +4,7 @@ local dashboard = import 'dashboard/dashboard.libsonnet';
 local section = import 'dashboard/section.libsonnet';
 local variable = import 'dashboard/variable.libsonnet';
 
-function(datasource, job, rate_time_range) dashboard.new(
+function(datasource, job) dashboard.new(
   grafana.dashboard.new(
     title='Tarantool dashboard',
     description='Dashboard for Tarantool application and database server monitoring, based on grafonnet library.',
@@ -55,83 +55,71 @@ function(datasource, job, rate_time_range) dashboard.new(
     datasource_type=variable.datasource_type.prometheus,
     datasource=datasource,
     job=job,
-    rate_time_range=rate_time_range,
   )
 ).addPanels(
   section.http(
     datasource_type=variable.datasource_type.prometheus,
     datasource=datasource,
     job=job,
-    rate_time_range=rate_time_range,
   )
 ).addPanels(
   section.net(
     datasource_type=variable.datasource_type.prometheus,
     datasource=datasource,
     job=job,
-    rate_time_range=rate_time_range,
   )
 ).addPanels(
   section.slab(
     datasource_type=variable.datasource_type.prometheus,
     datasource=datasource,
     job=job,
-    rate_time_range=rate_time_range,
   )
 ).addPanels(
   section.space(
     datasource_type=variable.datasource_type.prometheus,
     datasource=datasource,
     job=job,
-    rate_time_range=rate_time_range,
   )
 ).addPanels(
   section.vinyl(
     datasource_type=variable.datasource_type.prometheus,
     datasource=datasource,
     job=job,
-    rate_time_range=rate_time_range,
   )
 ).addPanels(
   section.cpu(
     datasource_type=variable.datasource_type.prometheus,
     datasource=datasource,
     job=job,
-    rate_time_range=rate_time_range,
   )
 ).addPanels(
   section.runtime(
     datasource_type=variable.datasource_type.prometheus,
     datasource=datasource,
     job=job,
-    rate_time_range=rate_time_range,
   )
 ).addPanels(
   section.luajit(
     datasource_type=variable.datasource_type.prometheus,
     datasource=datasource,
     job=job,
-    rate_time_range=rate_time_range,
   )
 ).addPanels(
   section.operations(
     datasource_type=variable.datasource_type.prometheus,
     datasource=datasource,
     job=job,
-    rate_time_range=rate_time_range,
   )
 ).addPanels(
   section.crud(
     datasource_type=variable.datasource_type.prometheus,
     datasource=datasource,
     job=job,
-    rate_time_range=rate_time_range,
   )
 ).addPanels(
   section.expirationd(
     datasource_type=variable.datasource_type.prometheus,
     datasource=datasource,
     job=job,
-    rate_time_range=rate_time_range,
   )
 )

dashboard/build/prometheus/dashboard_static.jsonnet

@@ -3,5 +3,4 @@ local dashboard_raw = import 'dashboard/build/prometheus/dashboard_raw.libsonnet
 dashboard_raw(
   datasource=std.extVar('DATASOURCE'),
   job=std.extVar('JOB'),
-  rate_time_range=std.extVar('RATE_TIME_RANGE'),
 ).build()

dashboard/build/prometheus/tdg_dashboard.libsonnet

@@ -6,7 +6,6 @@ local variable = import 'dashboard/variable.libsonnet';
 tdg_dashboard_raw(
   datasource=variable.datasource.prometheus,
   job=variable.prometheus.job,
-  rate_time_range=variable.prometheus.rate_time_range
 ).addInput(
   name='DS_PROMETHEUS',
   label='Prometheus',
@@ -20,12 +19,6 @@ tdg_dashboard_raw(
   type='constant',
   value='tarantool',
   description='Prometheus Tarantool metrics job'
-).addInput(
-  name='PROMETHEUS_RATE_TIME_RANGE',
-  label='Rate time range',
-  type='constant',
-  value='2m',
-  description='Time range for computing rps graphs with rate(). At the very minimum it should be two times the scrape interval.'
 ).addTemplate(
   grafana.template.custom(
     name='job',
@@ -34,12 +27,4 @@ tdg_dashboard_raw(
     hide='variable',
     label='Prometheus job',
   )
-).addTemplate(
-  grafana.template.custom(
-    name='rate_time_range',
-    query='${PROMETHEUS_RATE_TIME_RANGE}',
-    current='${PROMETHEUS_RATE_TIME_RANGE}',
-    hide='variable',
-    label='rate() time range',
-  )
 )