From b1a107580e7bd46964dfaa2e3f831dd767768f22 Mon Sep 17 00:00:00 2001
From: Krishan Thisera <krishan.thisera@yahoo.com>
Date: Wed, 1 Nov 2023 16:09:40 +1030
Subject: [PATCH] DO-1562: make the re-caching concurrency configurable

---
 packages/prerender-fargate/index.ts            |  2 ++
 .../lib/prerender-fargate-options.ts           | 18 +++++++++++++++++-
 .../prerender-fargate/lib/prerender-fargate.ts |  3 +++
 .../prerender-recache-api-construct.ts         |  6 +++++-
 4 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/packages/prerender-fargate/index.ts b/packages/prerender-fargate/index.ts
index ed7b803c..841bced1 100644
--- a/packages/prerender-fargate/index.ts
+++ b/packages/prerender-fargate/index.ts
@@ -1,6 +1,7 @@
 import { PrerenderFargate } from "./lib/prerender-fargate";
 import {
   PrerenderFargateOptions,
+  PrerenderFargateRecachingOptions,
   PrerenderFargateScalingOptions,
 } from "./lib/prerender-fargate-options";
 import { PrerenderTokenUrlAssociationOptions } from "./lib/recaching/prerender-tokens";
@@ -9,5 +10,6 @@ export {
   PrerenderFargate,
   PrerenderFargateOptions,
   PrerenderFargateScalingOptions,
+  PrerenderFargateRecachingOptions,
   PrerenderTokenUrlAssociationOptions,
 };
diff --git a/packages/prerender-fargate/lib/prerender-fargate-options.ts b/packages/prerender-fargate/lib/prerender-fargate-options.ts
index 95d1d22b..574ca0d1 100644
--- a/packages/prerender-fargate/lib/prerender-fargate-options.ts
+++ b/packages/prerender-fargate/lib/prerender-fargate-options.ts
@@ -1,5 +1,5 @@
 import { PrerenderTokenUrlAssociationOptions } from "./recaching/prerender-tokens";
-import * as ec2 from "aws-cdk-lib/aws-ec2";
+
 
 /**
  * Options for configuring the Prerender Fargate construct.
@@ -89,6 +89,11 @@ export interface PrerenderFargateOptions {
    * for most of the cases.
    */
   prerenderFargateScalingOptions?: PrerenderFargateScalingOptions;
+  /**
+   * Prerender Fargate Re-caching options
+   * This allows to alter the re-caching behavior. The default configuration should be sufficient.
+   */
+  prerenderFargateRecachingOptions?: PrerenderFargateRecachingOptions;
 }
 
 /**
@@ -137,3 +142,14 @@ export interface PrerenderFargateScalingOptions {
    */
   unhealthyThresholdCount?: number;
 }
+
+/**
+ * Prerender Fargate Re-caching options
+ */
+export interface PrerenderFargateRecachingOptions {
+  /**
+   * The maximum number of concurrent executions of the Prerender Re-cache API.
+   * @default - 1
+   */
+  maxConcurrentExecutions: number;
+}
\ No newline at end of file
diff --git a/packages/prerender-fargate/lib/prerender-fargate.ts b/packages/prerender-fargate/lib/prerender-fargate.ts
index 2988fc51..a0375985 100644
--- a/packages/prerender-fargate/lib/prerender-fargate.ts
+++ b/packages/prerender-fargate/lib/prerender-fargate.ts
@@ -100,6 +100,7 @@ export class PrerenderFargate extends Construct {
       prerenderName,
       minInstanceCount,
       prerenderFargateScalingOptions,
+      prerenderFargateRecachingOptions,
     } = props;
 
     // Create bucket for prerender storage
@@ -252,6 +253,8 @@ export class PrerenderFargate extends Construct {
       new PrerenderRecacheApi(this, `${prerenderName}-recache-api`, {
         prerenderS3Bucket: this.bucket,
         tokenList: Object.keys(tokenUrlAssociation.tokenUrlAssociation),
+        maxConcurrentExecutions:
+        prerenderFargateRecachingOptions?.maxConcurrentExecutions || 1,
       });
     }
   }
diff --git a/packages/prerender-fargate/lib/recaching/prerender-recache-api-construct.ts b/packages/prerender-fargate/lib/recaching/prerender-recache-api-construct.ts
index f197d29c..5adcba87 100644
--- a/packages/prerender-fargate/lib/recaching/prerender-recache-api-construct.ts
+++ b/packages/prerender-fargate/lib/recaching/prerender-recache-api-construct.ts
@@ -18,6 +18,10 @@ export interface PrerenderRecacheApiOptions {
    * A list of tokens used to authenticate API requests.
    */
   tokenList: string[];
+  /**
+   * Maximum number of concurrent executions of the Prerender Recache API.
+   */
+  maxConcurrentExecutions: number;
 }
 
 /**
@@ -48,8 +52,8 @@ export class PrerenderRecacheApi extends Construct {
     new LambdaToSqsToLambda(this, "prerenderRequestQueue", {
       existingProducerLambdaObj: apiHandler,
       existingConsumerLambdaObj: new NodejsFunction(this, "consumer", {
+        reservedConcurrentExecutions: options.maxConcurrentExecutions,
         timeout: Duration.seconds(60),
-        reservedConcurrentExecutions: 1,
       }),
       deployDeadLetterQueue: false,
       queueProps: { visibilityTimeout: Duration.minutes(60) },