[Backport][v1.73.x][Python Core][EventEngine] Fix Python reconnect issues: use iomgr backup poller when EE is disabled#39950
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yashykt merged 1 commit intogrpc:v1.73.xfrom Jun 23, 2025
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…en EE is disabled (grpc#39894) Fix the issue with gRPC Python Client not recovering in certain situations: grpc#38290, grpc#39113, grpc#39631. --- This PR: - Keeps iomgr backup poller enabled on platforms that do not support that have EventEngine / POSIX poller disabled. - Fixes and hardens Python's reconnect_test. This fixes issues with Python Client recovery in certain cases when it falls back to the backup poller. Note that currently Python disables POSIX poller manually via `GRPC_PLATFORM_SUPPORTS_POSIX_POLLING` due to currently unresolved fork issue. Unlike grpc#39131, this change is meant to be tested and merged to master, and then backported to past branches with broken python client reconnect logic. However, once Event Engine fork support is fixed, Python will switch to it by removing `GRPC_DO_NOT_INSTANTIATE_POSIX_POLLER` from all builds. After that, the backup poller should not be needed for Python. With the updated test, the case with python relying on the backup poller is covered, and we should be able to detect issues with Python having to rely on in after switching to EE. Closes grpc#39894 COPYBARA_INTEGRATE_REVIEW=grpc#39894 from sergiitk:python-fix-reconnect 239b330 PiperOrigin-RevId: 773549056
yashykt
approved these changes
Jun 23, 2025
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Backport of #39894 to v1.73.x.
Fix the issue with gRPC Python Client not recovering in certain situations: #38290, #39113, #39631.
This PR:
This fixes issues with Python Client recovery in certain cases when it falls back to the backup poller. Note that currently Python disables POSIX poller manually via
GRPC_PLATFORM_SUPPORTS_POSIX_POLLINGdue to currently unresolved fork issue.Unlike #39131, this change is meant to be tested and merged to master, and then backported to past branches with broken python client reconnect logic.
However, once Event Engine fork support is fixed, Python will switch to it by removing
GRPC_DO_NOT_INSTANTIATE_POSIX_POLLERfrom all builds. After that, the backup poller should not be needed for Python. With the updated test, the case with python relying on the backup poller is covered, and we should be able to detect issues with Python having to rely on in after switching to EE.