uWSGI OSError: write error

[jpmckinney]

We occasionally see errors reported to Sentry from uWSGI as simply "OSError: write error".

When looking in /var/log/uwsgi/app/ log files, we get more detail:

ocdskit-web.log.2.gz:Sat Apr 24 21:59:57 2021 - SIGPIPE: writing to a closed pipe/socket/fd (probably the client disconnected) on request /mapping-sheet/?source=https://standard.open-contracting.org/profiles/ppp/1.0/en/_static/patched/release-schema.json (ip 54.36.149.67) !!!
ocdskit-web.log.2.gz:Sat Apr 24 21:59:57 2021 - uwsgi_response_write_body_do(): Broken pipe [core/writer.c line 331] during GET /mapping-sheet/?source=https://standard.open-contracting.org/profiles/ppp/1.0/en/_static/patched/release-schema.json (54.36.149.67)
ocdskit-web.log.2.gz:OSError: write error

• cove-ocds
• covid19-backend

There are uWSGI options to ignore the errors, which would be fine if the error were caused by a client closing the connection before the response was written. However, it seems the error can also be caused by a timeout, in which case we'd want to change our timeout configuration in Apache and in uWSGI.

For now, this issue just creates noise in Sentry. We're not aware of it affecting a user (viz. timeout potential cause).

There is a lengthy uWSGI issue here: unbit/uwsgi#1623

[devZer0]

i see these errors in zulip django.log from time to time:

Wed Jun  2 05:54:14 2021 - SIGPIPE: writing to a closed pipe/socket/fd (probably the client disconnected) on request /api/v1/users/me/1/topics? (ip 5.147.234.117) !!!
Wed Jun  2 05:54:14 2021 - uwsgi_response_writev_headers_and_body_do(): Broken pipe [core/writer.c line 306] during GET /api/v1/users/me/1/topics? (5.147.234.117)
OSError: write error
Wed Jun  2 05:54:14 2021 - SIGPIPE: writing to a closed pipe/socket/fd (probably the client disconnected) on request /api/v1/users/me/1/topics? (ip 5.147.234.117) !!!
Wed Jun  2 05:54:14 2021 - uwsgi_response_writev_headers_and_body_do(): Broken pipe [core/writer.c line 306] during GET /api/v1/users/me/1/topics? (5.147.234.117)
OSError: write error

[jpmckinney]

Closing as errors occur quite rarely based on Sentry for cove-ocds.

If we set up the Data Review Tools at dedicated subdomains instead of proxying as part of either #266 or #145, then one potential cause for this error might go away.