AWS Lambda has released a new feature few months back, that allows developers to stream response payloads back to the client. This is a significant improvement over the previous behavior, which required Lambda functions to fully generate and buffer the response before returning it to the client. This could cause delays in the time to first byte (TTFB), especially for large responses.
With response payload streaming, Lambda functions can send partial responses back to the client as they become ready. This can significantly improve TTFB, as the client can start to render the response as soon as the first bytes are received.
In addition to improving TTFB, response payload streaming can also be used to improve the performance of long-running operations. For example, a Lambda function could stream the results of a large computation back to the client as they become available. This would allow the client to start using the results as soon as they are available, rather than having to wait for the entire computation to complete.
Response payload streaming is supported in all of the AWS regions where Lambda is available. To use it, you simply need to set the Content-Encoding header to chunked. The client will then be able to stream the response payload as it is generated.
Here are some additional things to keep in mind when using response payload streaming:
- The client must be able to handle partial responses.
- The response payload must be encoded using chunked encoding.
The maximum size of a streamed response is 20 MB.
Overall, response payload streaming is a powerful new feature that can improve the performance of Lambda functions. If you are developing a Lambda function that generates large responses or long-running computations, you should consider using response payload streaming to improve the performance of your application.
Here are some additional thoughts on the implications of this new feature:
- This could make Lambda a more attractive option for hosting web applications.
- It could also make Lambda a more viable option for real-time applications.
The ability to stream responses could also make it easier to integrate Lambda functions with other services, such as Kinesis and DynamoDB.
Overall, this is a significant new feature that could have a big impact on the way that Lambda is used. I am excited to see how developers use this feature to improve the performance of their applications.