From 42da5640ea6645b4e74d9454afa7d5a8a62b0639 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-1560: make the re-caching concurrency configurable

---
 packages/prerender-fargate/index.ts              |  2 ++
 .../lib/prerender-fargate-options.ts             | 16 ++++++++++++++++
 .../prerender-fargate/lib/prerender-fargate.ts   |  3 +++
 .../recaching/prerender-recache-api-construct.ts |  6 +++++-
 4 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/packages/prerender-fargate/index.ts b/packages/prerender-fargate/index.ts
index ed7b803c..244c3380 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,
+  PrerenderFargateReachingOptions,
   PrerenderFargateScalingOptions,
 } from "./lib/prerender-fargate-options";
 import { PrerenderTokenUrlAssociationOptions } from "./lib/recaching/prerender-tokens";
@@ -9,5 +10,6 @@ export {
   PrerenderFargate,
   PrerenderFargateOptions,
   PrerenderFargateScalingOptions,
+  PrerenderFargateReachingOptions,
   PrerenderTokenUrlAssociationOptions,
 };
diff --git a/packages/prerender-fargate/lib/prerender-fargate-options.ts b/packages/prerender-fargate/lib/prerender-fargate-options.ts
index 95d1d22b..ca4c4865 100644
--- a/packages/prerender-fargate/lib/prerender-fargate-options.ts
+++ b/packages/prerender-fargate/lib/prerender-fargate-options.ts
@@ -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.
+   */
+  prerenderFargateReachingOptions?: PrerenderFargateReachingOptions;
 }
 
 /**
@@ -137,3 +142,14 @@ export interface PrerenderFargateScalingOptions {
    */
   unhealthyThresholdCount?: number;
 }
+
+/**
+ * Prerender Fargate Re-caching options
+ */
+export interface PrerenderFargateReachingOptions {
+  /**
+   * 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..7cfc9c8e 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,
+      prerenderFargateReachingOptions,
     } = 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:
+          prerenderFargateReachingOptions?.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) },