Error: Premature close

[alxndrsn]

Written to stderr:

Error [ERR_STREAM_PREMATURE_CLOSE]: Premature close
    at new NodeError (node:internal/errors:387:5)
    at ServerResponse.onclose (node:internal/streams/end-of-stream:145:30)
    at ServerResponse.emit (node:events:525:35)
    at ServerResponse.emit (node:domain:489:12)
    at Socket.onServerResponseClose (node:_http_server:258:23)
    at Socket.emit (node:events:525:35)
    at Socket.emit (node:domain:489:12)
    at TCP.<anonymous> (node:net:757:14)

"Premature close" has been mentioned in previous issues:

• https://github.com/getodk/central-backend/issues/485
• https://github.com/getodk/central-backend/pull/480
• https://github.com/getodk/central-backend/issues/521
• https://github.com/getodk/central-backend/pull/637
• https://forum.getodk.org/t/postgres-error-causing-internal-server-error-500/37535

The error can be recreated fairly reliably (substitute IDs and auth credentials as appropriate):

for i in {1..20};do \
echo; echo "Starting iteration #$i..."; echo; \
(curl "localhost:8383/------------------------------ITERATION-[$i]-BEGINNING------------------------------"; \
tim=$((3 + $RANDOM % 12)); \
echo; echo "Running for $tim seconds..."; echo; \
timeout $tim siege -v \
http://localhost:8989/v1/projects/1/forms/all-widgets.svc/Submissions \
-H 'Authorization: Basic ...'); \
done

[yanokwa]

Can you also trigger a true premature close (e.g., cancelling a download halfway or shutting of the connection)? It'd be ideal if we could identify and ignore true premature closes.

[alxndrsn]

More consistent reproduction:

const { Socket } = require('node:net');

const s = new Socket(); 

s.on('connect', () => {
  s.write(
    'GET /v1/projects/1/forms/all-widgets.svc/Submissions HTTP/1.1\r\n' +
    'Host: localhost:8989\r\n' +
    'User-Agent: curl/7.68.0\r\n' +
    'Accept: */*\r\n' +
    'Authorization: Basic ...\r\n' +
    '\r\n' +
  '');
});
s.on('data', data => console.log('RECEIVED:', data.toString()));

s.connect('8989', 'localhost');
s.pause();

[alxndrsn]

Simpler reproduction:

$ curl http://localhost:8989/v1/projects/1/forms/all-widgets/submissions.csv.zip -H 'Authorization: Basic ...'
Warning: Binary output can mess up your terminal. Use "--output -" to tell 
Warning: curl to output it to your terminal anyway, or consider "--output 
Warning: <FILE>" to save to a file.

[lognaturel]

I've confirmed that I can trigger the error in Sentry by exiting out of the Power Query Editor in Excel (and presumably PowerBI) while a preview is being generated. These Sentry entries are all triggered by me in normal usage. The best way I see to limit the noisiness is to speed up some of those queries if we can.

[yanokwa]

Agreed that we should speed up the queries, but if Power BI is somehow not closing things properly, we could also not log "false" premature closes.

[alxndrsn]

Perhaps these errors should be caught and handled, and a Problem returned to the client if possible. However, it's still useful to monitor them in Sentry, so they should also be reported there.

This will probably require a top-level express error handler in lib/bin/run-server.js.

For another error that should be handled similarly, see #658.