feat: add http udf server

[sundy-li]

No description provided.

[flaneur2020]

is this considered as a standalone transport protocol other than flight? how does databend interacts with this http server?

[sundy-li]

is this considered as a standalone transport protocol other than flight? how does databend interacts with this http server?

I need to add http support in databend query later

[sundy-li]

http server handles much slower than flight when there are blocking io tasks (sleep)

CREATE OR REPLACE FUNCTION wait_concurrent (INT) RETURNS INT LANGUAGE python HANDLER = 'wait_concurrent' ADDRESS = 'http://0.0.0.0:8815';  --flight 3s

CREATE OR REPLACE FUNCTION wait_concurrent (INT) RETURNS INT LANGUAGE python HANDLER = 'wait_concurrent' ADDRESS = 'http://0.0.0.0:8818';  --http 12s

select wait_concurrent(number) from numbers(1000) ignore_result;