Reduce default API server workers to 1 #55707
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Change the default number of API server workers from 4 to 1 and add guidance to deploy multiple API servers for scaling instead of increasing workers per server. With FastAPI, sync code runs in an external thread pool, making multiple workers within a single api server less necessary than it was in our flask days. And with uvicorns new spawn behavior instead of fork, it means no shared copy-on-write memory between workers, so it's better to scale horizontally now.
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vatsrahul1001 approved these changes Sep 16, 2025
vatsrahul1001 approved these changes Sep 16, 2025
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| I should say, I think this is a safer default and (in my testing at least) avoids the timeout problems we've seen in #52270 even in a cpu constrained environment. My scale testing shows this change is roughly equivalent with 1 core, and a lot faster with half a core (especially for heavier requests). |
pierrejeambrun approved these changes Sep 16, 2025
kaxil approved these changes Sep 16, 2025
vincbeck approved these changes Sep 16, 2025
kaxil pushed a commit that referenced this pull request Sep 16, 2025
Change the default number of API server workers from 4 to 1 and add guidance to deploy multiple API servers for scaling instead of increasing workers per server. With FastAPI, sync code runs in an external thread pool, making multiple workers within a single api server less necessary than it was in our flask days. And with uvicorns new spawn behavior instead of fork, it means no shared copy-on-write memory between workers, so it's better to scale horizontally now. (cherry picked from commit 87fc469)
suman-himanshu pushed a commit to suman-himanshu/airflow that referenced this pull request Sep 17, 2025
Change the default number of API server workers from 4 to 1 and add guidance to deploy multiple API servers for scaling instead of increasing workers per server. With FastAPI, sync code runs in an external thread pool, making multiple workers within a single api server less necessary than it was in our flask days. And with uvicorns new spawn behavior instead of fork, it means no shared copy-on-write memory between workers, so it's better to scale horizontally now.
dstandish pushed a commit to astronomer/airflow that referenced this pull request Sep 19, 2025
Change the default number of API server workers from 4 to 1 and add guidance to deploy multiple API servers for scaling instead of increasing workers per server. With FastAPI, sync code runs in an external thread pool, making multiple workers within a single api server less necessary than it was in our flask days. And with uvicorns new spawn behavior instead of fork, it means no shared copy-on-write memory between workers, so it's better to scale horizontally now. (cherry picked from commit 87fc469)
abdulrahman305 bot pushed a commit to abdulrahman305/airflow that referenced this pull request Sep 30, 2025
Change the default number of API server workers from 4 to 1 and add guidance to deploy multiple API servers for scaling instead of increasing workers per server. With FastAPI, sync code runs in an external thread pool, making multiple workers within a single api server less necessary than it was in our flask days. And with uvicorns new spawn behavior instead of fork, it means no shared copy-on-write memory between workers, so it's better to scale horizontally now.
abdulrahman305 bot pushed a commit to abdulrahman305/airflow that referenced this pull request Oct 1, 2025
Change the default number of API server workers from 4 to 1 and add guidance to deploy multiple API servers for scaling instead of increasing workers per server. With FastAPI, sync code runs in an external thread pool, making multiple workers within a single api server less necessary than it was in our flask days. And with uvicorns new spawn behavior instead of fork, it means no shared copy-on-write memory between workers, so it's better to scale horizontally now.
abdulrahman305 bot pushed a commit to abdulrahman305/airflow that referenced this pull request Oct 2, 2025
Change the default number of API server workers from 4 to 1 and add guidance to deploy multiple API servers for scaling instead of increasing workers per server. With FastAPI, sync code runs in an external thread pool, making multiple workers within a single api server less necessary than it was in our flask days. And with uvicorns new spawn behavior instead of fork, it means no shared copy-on-write memory between workers, so it's better to scale horizontally now.
abdulrahman305 bot pushed a commit to abdulrahman305/airflow that referenced this pull request Oct 3, 2025
Change the default number of API server workers from 4 to 1 and add guidance to deploy multiple API servers for scaling instead of increasing workers per server. With FastAPI, sync code runs in an external thread pool, making multiple workers within a single api server less necessary than it was in our flask days. And with uvicorns new spawn behavior instead of fork, it means no shared copy-on-write memory between workers, so it's better to scale horizontally now.
abdulrahman305 bot pushed a commit to abdulrahman305/airflow that referenced this pull request Oct 4, 2025
Change the default number of API server workers from 4 to 1 and add guidance to deploy multiple API servers for scaling instead of increasing workers per server. With FastAPI, sync code runs in an external thread pool, making multiple workers within a single api server less necessary than it was in our flask days. And with uvicorns new spawn behavior instead of fork, it means no shared copy-on-write memory between workers, so it's better to scale horizontally now.
abdulrahman305 bot pushed a commit to abdulrahman305/airflow that referenced this pull request Oct 5, 2025
Change the default number of API server workers from 4 to 1 and add guidance to deploy multiple API servers for scaling instead of increasing workers per server. With FastAPI, sync code runs in an external thread pool, making multiple workers within a single api server less necessary than it was in our flask days. And with uvicorns new spawn behavior instead of fork, it means no shared copy-on-write memory between workers, so it's better to scale horizontally now.
abdulrahman305 bot pushed a commit to abdulrahman305/airflow that referenced this pull request Oct 5, 2025
Change the default number of API server workers from 4 to 1 and add guidance to deploy multiple API servers for scaling instead of increasing workers per server. With FastAPI, sync code runs in an external thread pool, making multiple workers within a single api server less necessary than it was in our flask days. And with uvicorns new spawn behavior instead of fork, it means no shared copy-on-write memory between workers, so it's better to scale horizontally now.
abdulrahman305 bot pushed a commit to abdulrahman305/airflow that referenced this pull request Oct 7, 2025
Change the default number of API server workers from 4 to 1 and add guidance to deploy multiple API servers for scaling instead of increasing workers per server. With FastAPI, sync code runs in an external thread pool, making multiple workers within a single api server less necessary than it was in our flask days. And with uvicorns new spawn behavior instead of fork, it means no shared copy-on-write memory between workers, so it's better to scale horizontally now.
abdulrahman305 bot pushed a commit to abdulrahman305/airflow that referenced this pull request Oct 8, 2025
Change the default number of API server workers from 4 to 1 and add guidance to deploy multiple API servers for scaling instead of increasing workers per server. With FastAPI, sync code runs in an external thread pool, making multiple workers within a single api server less necessary than it was in our flask days. And with uvicorns new spawn behavior instead of fork, it means no shared copy-on-write memory between workers, so it's better to scale horizontally now.
abdulrahman305 bot pushed a commit to abdulrahman305/airflow that referenced this pull request Oct 9, 2025
Change the default number of API server workers from 4 to 1 and add guidance to deploy multiple API servers for scaling instead of increasing workers per server. With FastAPI, sync code runs in an external thread pool, making multiple workers within a single api server less necessary than it was in our flask days. And with uvicorns new spawn behavior instead of fork, it means no shared copy-on-write memory between workers, so it's better to scale horizontally now.
abdulrahman305 bot pushed a commit to abdulrahman305/airflow that referenced this pull request Oct 10, 2025
Change the default number of API server workers from 4 to 1 and add guidance to deploy multiple API servers for scaling instead of increasing workers per server. With FastAPI, sync code runs in an external thread pool, making multiple workers within a single api server less necessary than it was in our flask days. And with uvicorns new spawn behavior instead of fork, it means no shared copy-on-write memory between workers, so it's better to scale horizontally now.
abdulrahman305 bot pushed a commit to abdulrahman305/airflow that referenced this pull request Oct 11, 2025
Change the default number of API server workers from 4 to 1 and add guidance to deploy multiple API servers for scaling instead of increasing workers per server. With FastAPI, sync code runs in an external thread pool, making multiple workers within a single api server less necessary than it was in our flask days. And with uvicorns new spawn behavior instead of fork, it means no shared copy-on-write memory between workers, so it's better to scale horizontally now.
abdulrahman305 bot pushed a commit to abdulrahman305/airflow that referenced this pull request Oct 12, 2025
Change the default number of API server workers from 4 to 1 and add guidance to deploy multiple API servers for scaling instead of increasing workers per server. With FastAPI, sync code runs in an external thread pool, making multiple workers within a single api server less necessary than it was in our flask days. And with uvicorns new spawn behavior instead of fork, it means no shared copy-on-write memory between workers, so it's better to scale horizontally now.
abdulrahman305 bot pushed a commit to abdulrahman305/airflow that referenced this pull request Oct 14, 2025
Change the default number of API server workers from 4 to 1 and add guidance to deploy multiple API servers for scaling instead of increasing workers per server. With FastAPI, sync code runs in an external thread pool, making multiple workers within a single api server less necessary than it was in our flask days. And with uvicorns new spawn behavior instead of fork, it means no shared copy-on-write memory between workers, so it's better to scale horizontally now.
abdulrahman305 bot pushed a commit to abdulrahman305/airflow that referenced this pull request Oct 15, 2025
Change the default number of API server workers from 4 to 1 and add guidance to deploy multiple API servers for scaling instead of increasing workers per server. With FastAPI, sync code runs in an external thread pool, making multiple workers within a single api server less necessary than it was in our flask days. And with uvicorns new spawn behavior instead of fork, it means no shared copy-on-write memory between workers, so it's better to scale horizontally now.
abdulrahman305 bot pushed a commit to abdulrahman305/airflow that referenced this pull request Oct 17, 2025
Change the default number of API server workers from 4 to 1 and add guidance to deploy multiple API servers for scaling instead of increasing workers per server. With FastAPI, sync code runs in an external thread pool, making multiple workers within a single api server less necessary than it was in our flask days. And with uvicorns new spawn behavior instead of fork, it means no shared copy-on-write memory between workers, so it's better to scale horizontally now.
abdulrahman305 bot pushed a commit to abdulrahman305/airflow that referenced this pull request Oct 19, 2025
Change the default number of API server workers from 4 to 1 and add guidance to deploy multiple API servers for scaling instead of increasing workers per server. With FastAPI, sync code runs in an external thread pool, making multiple workers within a single api server less necessary than it was in our flask days. And with uvicorns new spawn behavior instead of fork, it means no shared copy-on-write memory between workers, so it's better to scale horizontally now.
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Change the default number of API server workers from 4 to 1 and add guidance to deploy multiple API servers for scaling instead of increasing workers per server.
With FastAPI, sync code runs in an external thread pool, making multiple workers within a single api server less necessary than it was in our flask days. And with uvicorns new spawn behavior instead of fork, it means no shared copy-on-write memory between workers, so it's better to scale horizontally now.
Closes #52270