feat(exporter-jaeger): add forceFlush and timeout options (open-telemetry#301)

Author: mayurkale22

packages/opentelemetry-exporter-jaeger/src/jaeger.ts

@@ -31,10 +31,16 @@ export class JaegerExporter implements SpanExporter {
   private readonly _logger: types.Logger;
   private readonly _process: jaegerTypes.ThriftProcess;
   private readonly _sender: typeof jaegerTypes.UDPSender;
+  private readonly _forceFlush: boolean = true;
+  private readonly _flushTimeout: number;
 
   constructor(config: jaegerTypes.ExporterConfig) {
     this._logger = config.logger || new NoopLogger();
     const tags: jaegerTypes.Tag[] = config.tags || [];
+    if (config.forceFlush !== undefined) {
+      this._forceFlush = config.forceFlush;
+    }
+    this._flushTimeout = config.flushTimeout || 2000;
 
     this._sender = new jaegerTypes.UDPSender(config);
     this._process = {
@@ -55,15 +61,18 @@ export class JaegerExporter implements SpanExporter {
 
   /** Shutdown exporter. */
   shutdown(): void {
+    if (!this._forceFlush) return;
+    // Make an optimistic flush.
     this._sender.flush((numSpans: number, err?: string) => {
       if (err) {
         this._logger.error(`failed to flush span: ${err}`);
       }
     });
-    // Sleeping 2 seconds before closing the sender's connection to ensure all spans are flushed.
+    // Sleeping x seconds before closing the sender's connection to ensure
+    // all spans are flushed.
     setTimeout(() => {
       this._sender.close();
-    }, 2000);
+    }, this._flushTimeout);
   }
 
   /** Transform spans and sends to Jaeger service. */

packages/opentelemetry-exporter-jaeger/src/types.ts

@@ -26,6 +26,8 @@ export interface ExporterConfig {
   host?: string; // default: 'localhost'
   port?: number; // default: 6832
   maxPacketSize?: number; // default: 65000
+  forceFlush?: boolean; // default: true
+  flushTimeout?: number; // default: 2000
 }
 
 // Below require is needed as jaeger-client types does not expose the thrift,

packages/opentelemetry-exporter-jaeger/test/jaeger.test.ts

@@ -50,6 +50,41 @@ describe('JaegerExporter', () => {
       assert.strictEqual(process.tags[0].vType, 'STRING');
       assert.strictEqual(process.tags[0].vStr, '0.0.1');
     });
+
+    it('should construct an exporter with forceFlush and flushTimeout', () => {
+      const exporter = new JaegerExporter({
+        serviceName: 'opentelemetry',
+        forceFlush: true,
+        flushTimeout: 5000,
+      });
+      assert.ok(typeof exporter.export === 'function');
+      assert.ok(typeof exporter.shutdown === 'function');
+
+      assert.ok(exporter['_forceFlush']);
+      assert.strictEqual(exporter['_flushTimeout'], 5000);
+    });
+
+    it('should construct an exporter without forceFlush and flushTimeout', () => {
+      const exporter = new JaegerExporter({
+        serviceName: 'opentelemetry',
+      });
+      assert.ok(typeof exporter.export === 'function');
+      assert.ok(typeof exporter.shutdown === 'function');
+
+      assert.ok(exporter['_forceFlush']);
+      assert.strictEqual(exporter['_flushTimeout'], 2000);
+    });
+
+    it('should construct an exporter with forceFlush = false', () => {
+      const exporter = new JaegerExporter({
+        serviceName: 'opentelemetry',
+        forceFlush: false,
+      });
+      assert.ok(typeof exporter.export === 'function');
+      assert.ok(typeof exporter.shutdown === 'function');
+
+      assert.ok(!exporter['_forceFlush']);
+    });
   });
 
   describe('export', () => {