From 15dc30edf67dff8d6f83516988eb7b7d80feba04 Mon Sep 17 00:00:00 2001
From: Mitsuhiro Tanda <mitsuhiro.tanda@gmail.com>
Date: Fri, 13 Nov 2015 21:45:15 +0900
Subject: [PATCH 1/2] if there isn't enough datapoint, add null data point

---
 .../datasource/prometheus/datasource.js       | 37 ++++++++++++-------
 1 file changed, 23 insertions(+), 14 deletions(-)

diff --git a/public/app/plugins/datasource/prometheus/datasource.js b/public/app/plugins/datasource/prometheus/datasource.js
index c86fa2806d3..7e45c10246c 100644
--- a/public/app/plugins/datasource/prometheus/datasource.js
+++ b/public/app/plugins/datasource/prometheus/datasource.js
@@ -48,6 +48,7 @@ function (angular, _, moment, dateMath) {
       var end = getPrometheusTime(options.range.to, true);
 
       var queries = [];
+      options = _.clone(options);
       _.each(options.targets, _.bind(function(target) {
         if (!target.expr || target.hide) {
           return;
@@ -58,7 +59,13 @@ function (angular, _, moment, dateMath) {
 
         var interval = target.interval || options.interval;
         var intervalFactor = target.intervalFactor || 1;
-        query.step = this.calculateInterval(interval, intervalFactor);
+        target.step = query.step = this.calculateInterval(interval, intervalFactor);
+        var range = Math.ceil(end - start);
+        // Prometheus drop query if range/step > 11000
+        // calibrate step if it is too big
+        if (query.step !== 0 && range / query.step > 11000) {
+          target.step = query.step = Math.ceil(range / 11000);
+        }
 
         queries.push(query);
       }, this));
@@ -96,17 +103,7 @@ function (angular, _, moment, dateMath) {
     };
 
     PrometheusDatasource.prototype.performTimeSeriesQuery = function(query, start, end) {
-      var url = '/api/v1/query_range?query=' + encodeURIComponent(query.expr) + '&start=' + start + '&end=' + end;
-
-      var step = query.step;
-      var range = Math.ceil(end - start);
-      // Prometheus drop query if range/step > 11000
-      // calibrate step if it is too big
-      if (step !== 0 && range / step > 11000) {
-        step = Math.ceil(range / 11000);
-      }
-      url += '&step=' + step;
-
+      var url = '/api/v1/query_range?query=' + encodeURIComponent(query.expr) + '&start=' + start + '&end=' + end + '&step=' + query.step;
       return this._request('GET', url);
     };
 
@@ -221,8 +218,20 @@ function (angular, _, moment, dateMath) {
 
       metricLabel = createMetricLabel(md.metric, options);
 
-      dps = _.map(md.values, function(value) {
-        return [parseFloat(value[1]), value[0] * 1000];
+      var stepMs = parseInt(options.step.slice(0, -1)) * 1000;
+      var lastTimestamp = null;
+      _.each(md.values, function(value) {
+        var dp_value = parseFloat(value[1]);
+        if (_.isNaN(dp_value)) {
+          dp_value = null;
+        }
+
+        var timestamp = value[0] * 1000;
+        if (lastTimestamp && (timestamp - lastTimestamp) > stepMs) {
+          dps.push([null, lastTimestamp + stepMs]);
+        }
+        lastTimestamp = timestamp;
+        dps.push([dp_value, timestamp]);
       });
 
       return { target: metricLabel, datapoints: dps };

From a1fcd3c5b6247db96e10e3d138aea794ba945eb2 Mon Sep 17 00:00:00 2001
From: Mitsuhiro Tanda <mitsuhiro.tanda@gmail.com>
Date: Fri, 20 Nov 2015 15:33:52 +0900
Subject: [PATCH 2/2] import fix step calibration

---
 public/app/plugins/datasource/prometheus/datasource.js        | 4 ++--
 .../plugins/datasource/prometheus/specs/datasource_specs.ts   | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/public/app/plugins/datasource/prometheus/datasource.js b/public/app/plugins/datasource/prometheus/datasource.js
index 7e45c10246c..2c9279cee96 100644
--- a/public/app/plugins/datasource/prometheus/datasource.js
+++ b/public/app/plugins/datasource/prometheus/datasource.js
@@ -209,7 +209,7 @@ function (angular, _, moment, dateMath) {
         sec = 1;
       }
 
-      return Math.ceil(sec * intervalFactor) + 's';
+      return Math.ceil(sec * intervalFactor);
     };
 
     function transformMetricData(md, options) {
@@ -218,7 +218,7 @@ function (angular, _, moment, dateMath) {
 
       metricLabel = createMetricLabel(md.metric, options);
 
-      var stepMs = parseInt(options.step.slice(0, -1)) * 1000;
+      var stepMs = parseInt(options.step) * 1000;
       var lastTimestamp = null;
       _.each(md.values, function(value) {
         var dp_value = parseFloat(value[1]);
diff --git a/public/app/plugins/datasource/prometheus/specs/datasource_specs.ts b/public/app/plugins/datasource/prometheus/specs/datasource_specs.ts
index 2ac4992edef..58034d09cac 100644
--- a/public/app/plugins/datasource/prometheus/specs/datasource_specs.ts
+++ b/public/app/plugins/datasource/prometheus/specs/datasource_specs.ts
@@ -19,7 +19,7 @@ describe('PrometheusDatasource', function() {
     var results;
     var urlExpected = 'proxied/api/v1/query_range?query=' +
                       encodeURIComponent('test{job="testjob"}') +
-                      '&start=1443438675&end=1443460275&step=60s';
+                      '&start=1443438675&end=1443460275&step=60';
     var query = {
       range: { from: moment(1443438674760), to: moment(1443460274760) },
       targets: [{ expr: 'test{job="testjob"}' }],