feat(lambda-event-sources): batching window for sqs event source

packages/@aws-cdk/aws-lambda-event-sources/README.md

@@ -65,6 +65,7 @@ const queue = new sqs.Queue(this, 'MyQueue', {
 
 lambda.addEventSource(new SqsEventSource(queue, {
   batchSize: 10, // default
+  maxBatchingWindow: Duration.minutes(5),
 }));
 ```
 

packages/@aws-cdk/aws-lambda-event-sources/lib/sqs.ts

@@ -1,6 +1,6 @@
 import * as lambda from '@aws-cdk/aws-lambda';
 import * as sqs from '@aws-cdk/aws-sqs';
-import { Names } from '@aws-cdk/core';
+import { Duration, Names, Token } from '@aws-cdk/core';
 
 export interface SqsEventSourceProps {
   /**
@@ -14,6 +14,16 @@ export interface SqsEventSourceProps {
    */
   readonly batchSize?: number;
 
+  /**
+   * The maximum amount of time to gather records before invoking the function.
+   * Maximum of Duration.minutes(5)
+   *
+   * Valid Range: Minimum value of 0 minutes. Maximum value of 5 minutes.
+   *
+   * @default Duration.seconds(0)
+   */
+  readonly maxBatchingWindow?: Duration;
+
   /**
    * If the SQS event source mapping should be enabled.
    *
@@ -29,14 +39,30 @@ export class SqsEventSource implements lambda.IEventSource {
   private _eventSourceMappingId?: string = undefined;
 
   constructor(readonly queue: sqs.IQueue, private readonly props: SqsEventSourceProps = { }) {
-    if (this.props.batchSize !== undefined && (this.props.batchSize < 1 || this.props.batchSize > 10)) {
-      throw new Error(`Maximum batch size must be between 1 and 10 inclusive (given ${this.props.batchSize})`);
+    const maxBatchingWindow = this.props.maxBatchingWindow;
+    if (maxBatchingWindow !== undefined) {
+      if (queue.fifo) {
+        throw new Error('Batching window is not supported for FIFO queues');
+      }
+      if (maxBatchingWindow.toSeconds() < 0 || maxBatchingWindow.toSeconds() > 300) {
+        throw new Error(`Maximum batching window must be between 0 and 300 seconds (given ${maxBatchingWindow.toSeconds()})`);
+      }
+    }
+
+    if (this.props.batchSize !== undefined && !Token.isUnresolved(this.props.batchSize)) {
+      if (this.props.maxBatchingWindow !== undefined && (this.props.batchSize < 1 || this.props.batchSize > 10000)) {
+        throw new Error(`Maximum batch size must be between 1 and 10000 inclusive (given ${this.props.batchSize}) when batching window is specified.`);
+      }
+      if (this.props.maxBatchingWindow === undefined && (this.props.batchSize < 1 || this.props.batchSize > 10)) {
+        throw new Error(`Maximum batch size must be between 1 and 10 inclusive (given ${this.props.batchSize}) when batching window is not specified.`);
+      }
     }
   }
 
   public bind(target: lambda.IFunction) {
     const eventSourceMapping = target.addEventSourceMapping(`SqsEventSource:${Names.nodeUniqueId(this.queue.node)}`, {
       batchSize: this.props.batchSize,
+      maxBatchingWindow: this.props.maxBatchingWindow,
       enabled: this.props.enabled,
       eventSourceArn: this.queue.queueArn,
     });

packages/@aws-cdk/aws-lambda-event-sources/test/test.sqs.ts

@@ -85,6 +85,38 @@ export = {
     test.done();
   },
 
+  'unresolved batch size'(test: Test) {
+    // GIVEN
+    const stack = new cdk.Stack();
+    const fn = new TestFunction(stack, 'Fn');
+    const q = new sqs.Queue(stack, 'Q');
+    let batchSize : number;
+
+    // WHEN
+    fn.addEventSource(new sources.SqsEventSource(q, {
+      batchSize: cdk.Lazy.number({
+        produce() {
+          return batchSize;
+        },
+      }),
+    }));
+
+    // THEN
+    expect(stack).to(haveResource('AWS::Lambda::EventSourceMapping', {
+      'EventSourceArn': {
+        'Fn::GetAtt': [
+          'Q63C6E3AB',
+          'Arn',
+        ],
+      },
+      'FunctionName': {
+        'Ref': 'Fn9270CBC0',
+      },
+    }));
+
+    test.done();
+  },
+
   'fails if batch size is < 1'(test: Test) {
     // GIVEN
     const stack = new cdk.Stack();
@@ -113,6 +145,109 @@ export = {
     test.done();
   },
 
+  'batch size is > 10 and batch window is defined'(test: Test) {
+    // GIVEN
+    const stack = new cdk.Stack();
+    const fn = new TestFunction(stack, 'Fn');
+    const q = new sqs.Queue(stack, 'Q');
+
+    // WHEN
+    fn.addEventSource(new sources.SqsEventSource(q, {
+      batchSize: 1000,
+      maxBatchingWindow: cdk.Duration.minutes(5),
+    }));
+
+    // THEN
+    expect(stack).to(haveResource('AWS::Lambda::EventSourceMapping', {
+      'EventSourceArn': {
+        'Fn::GetAtt': [
+          'Q63C6E3AB',
+          'Arn',
+        ],
+      },
+      'FunctionName': {
+        'Ref': 'Fn9270CBC0',
+      },
+      'BatchSize': 1000,
+      'MaximumBatchingWindowInSeconds': 300,
+    }));
+
+    test.done();
+  },
+
+  'fails if batch size is > 10000 and batch window is defined'(test: Test) {
+    // GIVEN
+    const stack = new cdk.Stack();
+    const fn = new TestFunction(stack, 'Fn');
+    const q = new sqs.Queue(stack, 'Q');
+
+    // WHEN/THEN
+    test.throws(() => fn.addEventSource(new sources.SqsEventSource(q, {
+      batchSize: 11000,
+      maxBatchingWindow: cdk.Duration.minutes(5),
+    })), /Maximum batch size must be between 1 and 10000 inclusive \(given 11000\)/);
+
+    test.done();
+  },
+
+  'specific batch window'(test: Test) {
+    // GIVEN
+    const stack = new cdk.Stack();
+    const fn = new TestFunction(stack, 'Fn');
+    const q = new sqs.Queue(stack, 'Q');
+
+    // WHEN
+    fn.addEventSource(new sources.SqsEventSource(q, {
+      maxBatchingWindow: cdk.Duration.minutes(5),
+    }));
+
+    // THEN
+    expect(stack).to(haveResource('AWS::Lambda::EventSourceMapping', {
+      'EventSourceArn': {
+        'Fn::GetAtt': [
+          'Q63C6E3AB',
+          'Arn',
+        ],
+      },
+      'FunctionName': {
+        'Ref': 'Fn9270CBC0',
+      },
+      'MaximumBatchingWindowInSeconds': 300,
+    }));
+
+    test.done();
+  },
+
+  'fails if batch window defined for FIFO queue'(test: Test) {
+    // GIVEN
+    const stack = new cdk.Stack();
+    const fn = new TestFunction(stack, 'Fn');
+    const q = new sqs.Queue(stack, 'Q', {
+      fifo: true,
+    });
+
+    // WHEN/THEN
+    test.throws(() => fn.addEventSource(new sources.SqsEventSource(q, {
+      maxBatchingWindow: cdk.Duration.minutes(5),
+    })), /Batching window is not supported for FIFO queues/);
+
+    test.done();
+  },
+
+  'fails if batch window is > 5'(test: Test) {
+    // GIVEN
+    const stack = new cdk.Stack();
+    const fn = new TestFunction(stack, 'Fn');
+    const q = new sqs.Queue(stack, 'Q');
+
+    // WHEN/THEN
+    test.throws(() => fn.addEventSource(new sources.SqsEventSource(q, {
+      maxBatchingWindow: cdk.Duration.minutes(7),
+    })), /Maximum batching window must be between 0 and 300 seconds \(given 420\)/);
+
+    test.done();
+  },
+
   'contains eventSourceMappingId after lambda binding'(test: Test) {
     // GIVEN
     const stack = new cdk.Stack();