Change back to a streaming method for web server responses #730
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PR #729 aimed to improve performance by removing the use of stream_with_context from the response handling. While this did improve performance it meant that we're now hitting the 32mb response size limit that cloud run imposes for non-streaming responses. This update reintroduces a streaming response, but using a different method that doesn't have the same small chunk size that was causing the performance issue previously. The docs on this are pretty minimal but this is pulling together some info from both the flask docs on streaming: https://flask.palletsprojects.com/en/stable/patterns/streaming/ and the fast api docs on streaming a file-like binary response: https://fastapi.tiangolo.com/advanced/custom-response/#using-streamingresponse-with-file-like-objects
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dancoates
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Mar 26, 2025
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| @app.route('/<dataset>/<path:filename>') | ||
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Adding the extra iterfile function took this over an arbitrary complexity limit, to fix would need to refactor out some of the other code in the handler function, not keen to do that in this PR as it would make the diff and intent of the change unclear.
violetbrina
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Mar 26, 2025
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violetbrina
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Thanks for the links in the description. Made this a super fast review. Conceptually the returning the generator makes sense. Hope this works!
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PR #729 aimed to improve performance by removing the use of stream_with_context from the response handling. While this did improve performance it meant that we're now hitting the 32mb response size limit that cloud run imposes for non-streaming responses.
This update reintroduces a streaming response, but using a different method that doesn't have the same small chunk size that was causing the performance issue previously. The docs on this are pretty minimal but this is pulling together some info from both the flask docs on streaming:
https://flask.palletsprojects.com/en/stable/patterns/streaming/
and the fast api docs on streaming a file-like binary response: https://fastapi.tiangolo.com/advanced/custom-response/#using-streamingresponse-with-file-like-objects