WorkerLostError：celery + django

Question

[2015-04-29 13:31:48,547: ERROR/MainProcess] Process 'Worker-2' pid:34821 exited with 'signal 15 (SIGTERM)'
[2015-04-29 13:31:48,615: ERROR/MainProcess] Task products.tasks.init[44501581-6dea-4b38-91fe-04c837888fb4] raised unexpected: WorkerLostError('Worker exited prematurely: signal 15 (SIGTERM).',)
Traceback (most recent call last):
  File "/var/www/freelance/ve/local/lib/python2.7/site-packages/billiard/pool.py", line 1169, in mark_as_worker_lost
    human_status(exitcode)),
WorkerLostError: Worker exited prematurely: signal 15 (SIGTERM).

昨天我收到了这个错误。应该看哪些提示？ 我使用的是Django 1.6.2 和

celery==3.1.15
celery-with-redis==3.0
django-celery==3.1.16

谢谢。