From 8f139d0322c86fd146217447e53c85b8b2921831 Mon Sep 17 00:00:00 2001
From: Alexander Zobnin <alexanderzobnin@gmail.com>
Date: Tue, 30 Jul 2019 18:52:32 +0300
Subject: [PATCH] SLA over time: make intervals based on panel intervalMs, #728

---
 src/datasource-zabbix/constants.js            |  3 ++
 .../zabbix_api/zabbixAPIConnector.js          | 54 ++++++++++++-------
 src/datasource-zabbix/zabbix/zabbix.js        |  2 +-
 3 files changed, 38 insertions(+), 21 deletions(-)

diff --git a/src/datasource-zabbix/constants.js b/src/datasource-zabbix/constants.js
index 3c8de51..af3c8d1 100644
--- a/src/datasource-zabbix/constants.js
+++ b/src/datasource-zabbix/constants.js
@@ -34,3 +34,6 @@ export const TRIGGER_SEVERITY = [
   {val: 4, text: 'High'},
   {val: 5, text: 'Disaster'}
 ];
+
+/** Minimum interval for SLA over time (1 hour) */
+export const MIN_SLA_INTERVAL = 3600;
diff --git a/src/datasource-zabbix/zabbix/connectors/zabbix_api/zabbixAPIConnector.js b/src/datasource-zabbix/zabbix/connectors/zabbix_api/zabbixAPIConnector.js
index 6fd7931..f3a9a9b 100644
--- a/src/datasource-zabbix/zabbix/connectors/zabbix_api/zabbixAPIConnector.js
+++ b/src/datasource-zabbix/zabbix/connectors/zabbix_api/zabbixAPIConnector.js
@@ -1,7 +1,8 @@
 import _ from 'lodash';
+import kbn from 'grafana/app/core/utils/kbn';
 import * as utils from '../../../utils';
 import { ZabbixAPICore } from './zabbixAPICore';
-import { ZBX_ACK_ACTION_NONE, ZBX_ACK_ACTION_ACK, ZBX_ACK_ACTION_ADD_MESSAGE } from '../../../constants';
+import { ZBX_ACK_ACTION_NONE, ZBX_ACK_ACTION_ACK, ZBX_ACK_ACTION_ADD_MESSAGE, MIN_SLA_INTERVAL } from '../../../constants';
 
 /**
  * Zabbix API Wrapper.
@@ -316,25 +317,11 @@ export class ZabbixAPIConnector {
     return this.request('service.get', params);
   }
 
-  getSLA(serviceids, timeRange) {
-    let defaultRange = 86400;
-    let i;
-    let getIntervals = [];
-    let [timeFrom, timeTo] = timeRange;
-
-    for (i = timeFrom; i <= timeTo; i = i + defaultRange) {
-      if (timeTo < (i + defaultRange)) {
-        if (timeTo !== i) {
-          getIntervals.push({from : i, to : timeTo});
-        }
-      } else {
-        getIntervals.push({from : i, to : (i + defaultRange)});
-      }
-    }
-
-    var params = {
-      serviceids: serviceids,
-      intervals: getIntervals
+  getSLA(serviceids, timeRange, options) {
+    const intervals = buildSLAIntervals(timeRange, options.intervalMs);
+    const params = {
+      serviceids,
+      intervals
     };
     return this.request('service.getsla', params);
   }
@@ -536,3 +523,30 @@ function isNotAuthorized(message) {
     message === "Not authorized."
   );
 }
+
+function getSLAInterval(intervalMs) {
+  // Too many intervals may cause significant load on the database, so decrease number of resulting points
+  const resolutionRatio = 100;
+  const interval = kbn.round_interval(intervalMs * resolutionRatio) / 1000;
+  return Math.max(interval, MIN_SLA_INTERVAL);
+}
+
+function buildSLAIntervals(timeRange, intervalMs) {
+  let [timeFrom, timeTo] = timeRange;
+  const slaInterval = getSLAInterval(intervalMs);
+  const intervals = [];
+
+  // Align time range with calculated interval
+  timeFrom = Math.floor(timeFrom / slaInterval) * slaInterval;
+  timeTo = Math.ceil(timeTo / slaInterval) * slaInterval;
+
+  for (let i = timeFrom; i <= timeTo - slaInterval; i += slaInterval) {
+    intervals.push({
+      from : i,
+      to : (i + slaInterval)
+    });
+
+  }
+
+  return intervals;
+}
diff --git a/src/datasource-zabbix/zabbix/zabbix.js b/src/datasource-zabbix/zabbix/zabbix.js
index 35bb96a..74139a4 100644
--- a/src/datasource-zabbix/zabbix/zabbix.js
+++ b/src/datasource-zabbix/zabbix/zabbix.js
@@ -363,7 +363,7 @@ export class Zabbix {
       itServices = _.filter(itServices, {'serviceid': target.itservice.serviceid});
     }
     let itServiceIds = _.map(itServices, 'serviceid');
-    return this.zabbixAPI.getSLA(itServiceIds, timeRange)
+    return this.zabbixAPI.getSLA(itServiceIds, timeRange, options)
     .then(slaResponse => {
       return _.map(itServiceIds, serviceid => {
         let itservice = _.find(itServices, {'serviceid': serviceid});