We observe quite a weird issue with Data Import Tool on an instance of ERP Next running in production mode.
The data import tool will freeze (with no further changes to the import progress bar and no error messages shown in UI) and hang indefinitely. At the same time we see the following in web.error.log
[2016-12-12 16:13:15 +0000]  [CRITICAL] WORKER TIMEOUT (pid:23568)
[2016-12-12 16:13:15 +0000]  [INFO] Worker exiting (pid: 23568)
[2016-12-12 16:13:15 +0000]  [INFO] Booting worker with pid: 23585
No other error messages detected in any of different error logs on the backend.
We tried increasing the worker timeout values (actually we doubled it) with no luck.
We were trying to upload csv files with about 5000 records for Address DocType as we observed this problem. The same csv file was processed successfully by Data Import Tool of another ERP Next instance configured to run in Developer Mode.
Has anyone observed the issues like this in past? What is the best way to address it?
Just for the record, both ERP Next instances referred above run the same configuration as follows
- ERPNext: v7.1.23
- Frappe Framework: v7.1.24