Unable to send large file data from S3 to RDS MySQL

I am not receiving any errors when i check my database the data is transfered

Hello! Actually, there could be several reasons why you're unable to transfer larger files from S3 to RDS, especially when using a Lambda function. Let's go through some common issues and potential solutions:

Lambda Execution Timeout:

• AWS Lambda has a maximum execution time, which by default is 3 seconds but can be set up to 15 minutes. If your function is trying to process a large file and the processing time exceeds the set timeout, the function will be terminated.
• Solution: Increase the timeout of your Lambda function. However, be aware that very long-running Lambda functions can be expensive, so make sure you're optimizing your code and only increasing the timeout as necessary.

Lambda Memory Limit:

• Lambda functions have a memory limit, ranging from 128 MB to 10,240 MB. If your function runs out of memory, it will be terminated.
• Solution: Increase the memory allocated to your Lambda function. This will also proportionally increase the CPU, network bandwidth, and disk I/O available to the function.

RDS Instance Limitations:

• A t3.micro instance has limited CPU and I/O capabilities. If you're trying to insert a large number of rows at once, the instance might become overwhelmed.
• Solution: Optimize your insert queries (e.g., use batch inserts). Consider upgrading your RDS instance type if you frequently deal with large datasets. Monitor RDS metrics to see if CPU, memory, or I/O is being maxed out during the insert process.

Database Connection Timeout:

• If the Lambda function takes too long to process the file before inserting into RDS, the database connection might time out.
• Solution: Ensure you're establishing the database connection after processing the file and just before inserting the data. Also, consider using connection pooling.

VPC Configuration:

• If your Lambda function and RDS instance are in a VPC, there might be some network misconfigurations.
• Solution: Ensure that your Lambda function has the correct VPC, subnet, and security group settings to communicate with your RDS instance.

Error Handling and Logging:

• To pinpoint the exact issue, ensure your code has proper error handling and logging. Check the CloudWatch logs for any errors or anomalies during the Lambda function execution.

RDS Storage:

• Even though this is less likely (given that you're dealing with a 1 MB file), ensure that your RDS instance has enough storage available.

Recommendations:

• Optimization: Before increasing resources (which can add cost), try to optimize your Lambda function. For example, instead of inserting rows one by one, batch them and use bulk insert queries.
• Monitoring and Debugging: Use AWS CloudWatch to monitor Lambda executions, RDS metrics, and to check logs for any errors or messages.
• Testing: Test the Lambda function locally with large files to see if there's an issue with the code itself.

Lastly, if you can share the error messages or logs from CloudWatch, it would be helpful in diagnosing the exact problem.