Resolving Timeout Issues When Retrieving AWS Secrets in Java Lambda Functions

Learn how to effectively retrieve AWS Secrets in Java Lambda functions, solve timeout issues, and optimize memory usage.
---

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Unable to retrieve AWS Secrets from Lambda running Java

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Resolving Timeout Issues When Retrieving AWS Secrets in Java Lambda Functions

If you are working with AWS Lambda functions written in Java, you may encounter situations where your function times out when trying to retrieve secrets from AWS Secrets Manager. This can be particularly frustrating, especially if the same code works perfectly in your local IDE. In this guide, we'll dive into a common issue encountered when using AWS Lambda functions and provide actionable solutions to resolve timeout problems when getting secrets.

The Problem

Imagine you have an AWS Lambda function that handles requests from Discord and uses AWS Secrets Manager to store sensitive information like tokens. When the Lambda function runs, it frequently times out while trying to access these secrets.

Key Symptoms

The Lambda times out without retrieving the required secrets.

The logs indicate that the function is stuck before logging "Got secret value".

Even after testing the code in your local environment, it fails when executed on AWS.

The Setup

The initial setup in the Lambda function includes a custom handler to fetch secrets and verify requests. The code you might be using is as follows:

[[See Video to Reveal this Text or Code Snippet]]

Unpacking the Solution

1. Understanding Initialization Time

Java-based AWS Lambdas require some time to initialize resources, especially when creating clients for AWS services. If your Lambda times out, it may simply be that the client creation process is taking too long.

2. Make the Secrets Manager Client Static

One effective workaround is to make the Secrets Manager client a static variable. By doing this, the client is initialized only once, which saves time during each function invocation:

[[See Video to Reveal this Text or Code Snippet]]

3. Increasing Memory Allocation

In some cases, even after addressing initialization issues, you may run into out-of-memory exceptions. Java applications, especially AWS Lambdas, can consume a significant amount of memory during execution. If you receive an out-of-memory error, consider increasing the memory allocation for your Lambda function.

Recommended Memory Size: Increase to at least 256 MB or more, depending on the complexity of your operations.

4. Verifying Permissions

Ensure that your Lambda function has the necessary IAM permissions to access Secrets Manager. Permissions should include:

secretsmanager:GetSecretValue

secretsmanager:DescribeSecret

secretsmanager:ListSecrets

With the correct permissions and static initialization in place, your function should be able to retrieve secrets without timing out.

Conclusion

Facing timeout issues while retrieving AWS secrets in Java Lambda functions can be daunting, but understanding how these functions work can help you find solutions quickly. By following the steps outlined in this post — particularly making your AWS Secrets Manager client static and increasing memory allocation — you can optimize your function and enhance its reliability.

Remember to monitor your logs during testing and adjust your configuration as necessary. Happy coding!