Threads in celery 3.1.5

Question

I'm trying to porting my django application from celery 3.0.24 to 3.1.5, but I have troubles in executing a task containing which contains threads.

With 3.0.23 that worked, but with 3.1.5 I get:

[2013-11-22 15:26:39,740: ERROR/MainProcess] Task tss.tasks.buildTileLayer[2dd1d834-0286-4a03-85b1-67ee682f26b3] raised exception: AssertionError('daemonic processes are not allowed to have children',)
Traceback (most recent call last):
  File "/usr/lib/python2.6/site-packages/celery/app/trace.py", line 218, in trace_task
R = retval = fun(*args, **kwargs)
  File "/usr/lib/python2.6/site-packages/celery/app/trace.py", line 398, in __protected_call__
return self.run(*args, **kwargs)
  File "/opt/tss2/software/tss_proj/tss/tasks.py", line 268, in buildTileLayer
render_tiles_test_2(origBbox, bbox, str(mapFilePath), str(tilesDirPathTmp), minZoom, maxZoom, shpName)
  File "/opt/tss2/software/tss_proj/tss/tiles_test_2.py", line 78, in render_tiles_test_2
render_thread.start()
  File "/usr/lib64/python2.6/multiprocessing/process.py", line 98, in start
'daemonic processes are not allowed to have children'
AssertionError: daemonic processes are not allowed to have children

Am I missing some new configuration variable maybe?

Answer 1

There is a ticket on GitHub about this issue: https://github.com/celery/celery/issues/1709.