From 79d9ff802f65629dcea01f7343c2f106b0cffcf2 Mon Sep 17 00:00:00 2001
From: Mayur Kale <mayurkale@google.com>
Date: Mon, 26 Aug 2019 15:03:16 -0700
Subject: [PATCH] Fix: add batch limit for stackdriver exporter

---
 .../src/stackdriver-monitoring-utils.ts       |  9 ++++++
 .../src/stackdriver-monitoring.ts             | 14 ++++++++
 .../test/test-stackdriver-monitoring-utils.ts | 32 +++++++++++++++++++
 3 files changed, 55 insertions(+)

diff --git a/packages/opencensus-exporter-stackdriver/src/stackdriver-monitoring-utils.ts b/packages/opencensus-exporter-stackdriver/src/stackdriver-monitoring-utils.ts
index 277783626..22cf3a86c 100644
--- a/packages/opencensus-exporter-stackdriver/src/stackdriver-monitoring-utils.ts
+++ b/packages/opencensus-exporter-stackdriver/src/stackdriver-monitoring-utils.ts
@@ -108,6 +108,15 @@ export function createTimeSeriesList(
   return timeSeriesList;
 }
 
+/** Returns an array with arrays of the given size. */
+export function partitionList(list: TimeSeries[], chunkSize: number) {
+  const results = [];
+  while (list.length) {
+    results.push(list.splice(0, chunkSize));
+  }
+  return results;
+}
+
 /** Creates Metric type. */
 function createMetricType(name: string, metricPrefix: string): string {
   return path.join(metricPrefix, name);
diff --git a/packages/opencensus-exporter-stackdriver/src/stackdriver-monitoring.ts b/packages/opencensus-exporter-stackdriver/src/stackdriver-monitoring.ts
index e1a914673..b2cb91096 100644
--- a/packages/opencensus-exporter-stackdriver/src/stackdriver-monitoring.ts
+++ b/packages/opencensus-exporter-stackdriver/src/stackdriver-monitoring.ts
@@ -34,6 +34,7 @@ import { getDefaultResource } from './common-utils';
 import {
   createMetricDescriptorData,
   createTimeSeriesList,
+  partitionList,
 } from './stackdriver-monitoring-utils';
 import {
   MonitoredResource,
@@ -49,6 +50,10 @@ const OC_HEADER = {
   'x-opencensus-outgoing-request': 0x1,
 };
 
+// Stackdriver Monitoring v3 only accepts up to 200 TimeSeries per
+// CreateTimeSeries call.
+const MAX_BATCH_EXPORT_SIZE = 200;
+
 google.options({ headers: OC_HEADER });
 const monitoring = google.monitoring('v3');
 let auth = globalAuth;
@@ -184,6 +189,15 @@ export class StackdriverStatsExporter implements StatsEventListener {
       return Promise.resolve();
     }
 
+    for (const batchedTimeSeries of partitionList(
+      timeSeries,
+      MAX_BATCH_EXPORT_SIZE
+    )) {
+      this._createTimeSeries(batchedTimeSeries);
+    }
+  }
+
+  private async _createTimeSeries(timeSeries: TimeSeries[]) {
     return this.authorize().then(authClient => {
       const request = {
         name: `projects/${this.projectId}`,
diff --git a/packages/opencensus-exporter-stackdriver/test/test-stackdriver-monitoring-utils.ts b/packages/opencensus-exporter-stackdriver/test/test-stackdriver-monitoring-utils.ts
index 8feae4e88..202d05f7d 100644
--- a/packages/opencensus-exporter-stackdriver/test/test-stackdriver-monitoring-utils.ts
+++ b/packages/opencensus-exporter-stackdriver/test/test-stackdriver-monitoring-utils.ts
@@ -32,12 +32,14 @@ import {
   createTimeSeriesList,
   OPENCENSUS_TASK_VALUE_DEFAULT,
   TEST_ONLY,
+  partitionList,
 } from '../src/stackdriver-monitoring-utils';
 import {
   Distribution,
   MetricDescriptor,
   MetricKind,
   ValueType,
+  TimeSeries,
 } from '../src/types';
 import * as nocks from './nocks';
 
@@ -616,4 +618,34 @@ describe('Stackdriver Stats Exporter Utils', () => {
       });
     });
   });
+
+  describe('partitionList()', () => {
+    const timeSeriesList: TimeSeries[] = [];
+    for (let i = 0; i < 205; i++) {
+      timeSeriesList.push({
+        metric: {
+          type: 'custom.googleapis.com/opencensus/metric-name-' + i,
+          labels: {},
+        },
+        resource: { type: 'global', labels: {} },
+        metricKind: MetricKind.GAUGE,
+        valueType: ValueType.INT64,
+        points: [
+          {
+            interval: { endTime: '2019-01-09T01:52:55.00000001Z' },
+            value: {
+              int64Value: i,
+            },
+          },
+        ],
+      });
+    }
+
+    it('should return a partition lists', () => {
+      const list = partitionList(timeSeriesList, 200);
+      assert.strictEqual(list.length, 2);
+      assert.strictEqual(list[0].length, 200);
+      assert.strictEqual(list[1].length, 5);
+    });
+  });
 });