title: What is the propriate number of gevent greenlet in Celery startup command line
body: <p>For gevent pool, we could use the paramter '-c' to specify the greenlet number. As the following shows.</p>
  
  <pre><code>celery worker -A celerytasks.celery_worker_init -P gevent -c 1000 --loglevel=info
  </code></pre>
  
  <p>But what is the propriate value for it? </p>
  
  <p>And what does it really mean for 'greenlet number'? If I specify 1000 greenlets, what will happen if they are used out?</p>