Option to sleep between max quota requests

packages/cloudwatch-logs-auto-subscribe/README.md

@@ -56,3 +56,7 @@ For more details, read this [post](https://theburningmonk.com/2019/05/how-to-inc
 `FilterPattern`: (Optional) if specified, will override the filter pattern used to create the subscription.
 
 `UnsubscribeOnDelete`: (Optional) whether to remove the subscription filters that were added by this app. Defaults to "false", allowed values are "true" or "false".
+
+`SleepBetweenMaxQuotaRequests`: (optional) Amount of time in milliseconds to sleep after making {AwsMaxRequestsPerSecQuota} consecutive requests. It might be useful if an AWS account has a large amount of LogGroups or if experiencing Rate Exceeded throttling frequently. Suggested to use a value equal or bellow 1000, as quotas are per second. Defaults to 0.
+
+`AwsMaxRequestsPerSecQuota`: (optional) AWS quota for the max number of requests per second on DescribeLogGroups. This parameter is only used when SleepBetweenMaxQuotaRequests is greater than 0. More info: https://docs.aws.amazon.com/AmazonCloudWatch/latest/logs/cloudwatch_limits_cwl.html. Defaults to 5.

packages/cloudwatch-logs-auto-subscribe/functions/subscribe.js

@@ -3,17 +3,27 @@ const cloudWatchLogs = require("./lib/cloudwatch-logs");
 const log = require("@dazn/lambda-powertools-logger");
 
 const { FILTER_NAME, DESTINATION_ARN } = process.env;
+const SLEEP_BETWEEN_MAX_QUOTA_REQUESTS = parseInt(process.env.SLEEP_BETWEEN_MAX_QUOTA_REQUESTS, 10);
+const AWS_MAX_REQUESTS_PER_SEC_QUOTA = parseInt(process.env.AWS_MAX_REQUESTS_PER_SEC_QUOTA, 10);
+
+function sleep(milliseconds) {
+	return new Promise(r => setTimeout(r, milliseconds));
+}
 
 module.exports.existingLogGroups = async () => {
 	const logGroupNames = await cloudWatchLogs.getLogGroups();
-	for (const logGroupName of logGroupNames) {
+	for  (let log_group_index = 0; log_group_index < logGroupNames.length; log_group_index++) {
+	  const logGroupName = logGroupNames[log_group_index];
 		try {
-			if (await filter(logGroupName)) {				
+			if (await filter(logGroupName)) {
 				await subscribe(logGroupName);
 			}
 		} catch(error) {
 			log.warn("cannot process existing log group, skipped...", { logGroupName }, error);
 		}
+		if (SLEEP_BETWEEN_MAX_QUOTA_REQUESTS && ((log_group_index + 1) % AWS_MAX_REQUESTS_PER_SEC_QUOTA == 0)) {
+		  await sleep(SLEEP_BETWEEN_MAX_QUOTA_REQUESTS);
+		}
 	}
 };
 
@@ -154,3 +164,4 @@ const unsubscribe = async (logGroupName) => {
 		log.error("failed to unsubscribe log group", { logGroupName }, err);
 	}
 };
+

packages/cloudwatch-logs-auto-subscribe/functions/subscribe.test.js

@@ -20,6 +20,8 @@ console.log = jest.fn();
 beforeEach(() => {
 	process.env.RETRY_MIN_TIMEOUT = "100";
 	process.env.RETRY_MAX_TIMEOUT = "100";
+	process.env.SLEEP_BETWEEN_MAX_QUOTA_REQUESTS = "0";
+	process.env.AWS_MAX_REQUESTS_PER_SEC_QUOTA = "5";
 	process.env.FILTER_NAME = "ship-logs";
 	process.env.TAGS_MODE = "OR";
 	process.env.EXCLUDE_TAGS_MODE = "OR";

packages/cloudwatch-logs-auto-subscribe/template.yml

@@ -31,6 +31,8 @@ Globals:
         FILTER_PATTERN: !Ref FilterPattern
         ROLE_ARN: !GetAtt CloudWatchToKinesisRole.Arn
         LOG_LEVEL: INFO
+        SLEEP_BETWEEN_MAX_QUOTA_REQUESTS: !Ref SleepBetweenMaxQuotaRequests
+        AWS_MAX_REQUESTS_PER_SEC_QUOTA: !Ref AwsMaxRequestsPerSecQuota
 
 Conditions:
   Unsubscribe: !Equals [!Ref UnsubscribeOnDelete, 'true']
@@ -271,3 +273,17 @@ Parameters:
     Default: 6
     Description: >
       (optional) whether to increase the default lambda timeout".
+  SleepBetweenMaxQuotaRequests:
+    Type: Number
+    Default: 0
+    Description: >
+      (optional) Amount of time to sleep after making {AwsMaxRequestsPerSecQuota} consecutive requests.
+      It might be useful if an AWS account has a large amount of LogGroups or if experiencing Rate Exceeded throttling  
+      frequently".
+  AwsMaxRequestsPerSecQuota:
+    Type: Number
+    Default: 5
+    Description: >
+      (optional) AWS quota for the max number of requests per second on DescribeLogGroups. 
+      This parameter is only used when SleepBetweenMaxQuotaRequests is greater than 0. 
+      More info: https://docs.aws.amazon.com/AmazonCloudWatch/latest/logs/cloudwatch_limits_cwl.html. Defaults to 5".