<h1 dir="auto">Checklist</h1>
<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have included the output of celery -A proj report in the issue.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have included all related issues and possible duplicate issues in this issue.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have included the contents of pip freeze in the issue.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have verified that the issue exists against the master branch of Celery.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have tried reproducing the issue on more than one message broker and/or result backend.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have tried reproducing the issue on more than one workers pool.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have tried reproducing the issue with retries, ETA/Countdown &amp; rate limits disabled.</li>
</ul>
<h2 dir="auto">Related Issues and Possible Duplicates</h2>
<h4 dir="auto">Related Issues</h4>
<ul dir="auto">
<li>None</li>
</ul>
<h4 dir="auto">Possible Duplicates</h4>
<ul dir="auto">
<li><a class="issue-link js-issue-link" data-error-text="Failed to load title" data-id="97457005" data-permission-text="Title is private" data-url="https://github.com/celery/celery/issues/2727" data-hovercard-type="issue" data-hovercard-url="/celery/celery/issues/2727/hovercard" href="https://github.com/celery/celery/issues/2727">#2727</a> - symptoms are similar, however that issue doesn't originally mention the transport and at least one user there mentioned transport:redis, for which I can't reproduce the problem.</li>
</ul>
<h2 dir="auto">Environment &amp; Settings</h2>
<p dir="auto"><strong>Celery version</strong>:</p>
<details>
<summary><b><code class="notranslate">celery report</code> Output:</b></summary>
<p dir="auto">
</p><div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="software -&gt; celery:4.2.2 (windowlicker) kombu:4.3.0 py:2.7.16
            billiard:3.5.0.5 qpid:N/A
platform -&gt; system:Linux arch:64bit imp:CPython
loader   -&gt; celery.loaders.app.AppLoader
settings -&gt; transport:qpid results:rpc:///

broker_url: u'qpid://localhost:5672//'
result_backend: u'rpc:///'"><pre class="notranslate"><code class="notranslate">software -&gt; celery:4.2.2 (windowlicker) kombu:4.3.0 py:2.7.16
            billiard:3.5.0.5 qpid:N/A
platform -&gt; system:Linux arch:64bit imp:CPython
loader   -&gt; celery.loaders.app.AppLoader
settings -&gt; transport:qpid results:rpc:///

broker_url: u'qpid://localhost:5672//'
result_backend: u'rpc:///'
</code></pre></div>
<p dir="auto"></p>
</details>
<h1 dir="auto">Steps to Reproduce</h1>
<h2 dir="auto">Required Dependencies</h2>
<ul dir="auto">
<li><strong>Minimal Python Version</strong>: Unknown</li>
<li><strong>Minimal Broker Version</strong>: Unknown</li>
<li><strong>Minimal Result Backend Version</strong>: Unknown</li>
<li><strong>Minimal OS and/or Kernel Version</strong>: Unknown</li>
<li><strong>Minimal Broker Client Version</strong>: Unknown</li>
<li><strong>Minimal Result Backend Client Version</strong>: Unknown</li>
<li>Must use qpid transport (not reproducible on rabbitmq or redis transports)</li>
</ul>
<h3 dir="auto">Python Packages</h3>

<details>
<summary><b><code class="notranslate">pip freeze</code> Output:</b></summary>
<p dir="auto">
</p><div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="amqp==2.4.2
billiard==3.5.0.5
celery==4.2.2
kombu==4.3.0
pytz==2018.9
qpid-python==1.36.0.post1
qpid-tools==1.36.0.post1
redis==3.2.1
vine==1.3.0"><pre class="notranslate"><code class="notranslate">amqp==2.4.2
billiard==3.5.0.5
celery==4.2.2
kombu==4.3.0
pytz==2018.9
qpid-python==1.36.0.post1
qpid-tools==1.36.0.post1
redis==3.2.1
vine==1.3.0
</code></pre></div>
<p dir="auto"></p>
</details>
<h2 dir="auto">Minimally Reproducible Test Case</h2>
<p dir="auto">The following gist has testcases for revoking a task in progress:</p>
<p dir="auto"><a href="https://gist.github.com/rohanpm/78480b28b6c3e26fd9e33e999c899ee8">https://gist.github.com/rohanpm/78480b28b6c3e26fd9e33e999c899ee8</a></p>
<h1 dir="auto">Expected Behavior</h1>
<p dir="auto">When <code class="notranslate">task2.revoke(terminate=True)</code> is called, task2 is terminated.  The worker continues to execute subsequent tasks.</p>
<h1 dir="auto">Actual Behavior</h1>
<p dir="auto">When <code class="notranslate">task2.revoke(terminate=True)</code> is called, one of the following happens:</p>
<ul dir="auto">
<li>If there's no more tasks in the queue:<br>
-- task2 is terminated, but the worker then hangs and doesn't process any further tasks.</li>
<li>If there are tasks in the queue:<br>
-- task2 is not terminated, the worker continues executing task2 and subsequent tasks as if no revoke call was made</li>
</ul>
<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have checked the <a href="https://github.com/celery/celery/issues?q=is%3Aissue+label%3A%22Issue+Type%3A+Enhancement%22+-label%3A%22Category%3A+Documentation%22">issues list</a><br>
for similar or identical enhancement to an existing feature.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have checked the <a href="https://github.com/celery/celery/pulls?q=is%3Apr+label%3A%22Issue+Type%3A+Enhancement%22+-label%3A%22Category%3A+Documentation%22">pull requests list</a><br>
for existing proposed enhancements.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have checked the <a href="https://github.com/celery/celery/commits/master">commit log</a><br>
to find out if the if the same enhancement was already implemented in the<br>
master branch.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have included all related issues and possible duplicate issues in this issue<br>
(If there are none, check this box anyway).</li>
</ul>
<h2 dir="auto">Related Issues and Possible Duplicates</h2>
<p dir="auto">None I could find on the issue tracker.</p>
<h1 dir="auto">Brief Summary</h1>
<p dir="auto">The <a href="https://docs.celeryproject.org/en/stable/userguide/configuration.html#new-lowercase-settings" rel="nofollow">Celery 4.0 lowercase name change</a> brings zero benefit for developer but causes downsides in the form of name and style collisions in existing configuration files/classes.</p>
<h1 dir="auto">Design</h1>
<h2 dir="auto">Architectural Considerations</h2>
<p dir="auto">None</p>
<h2 dir="auto">Proposed Behavior</h2>
<p dir="auto">Allow people to keep the old behaviour because the new one isn't beneficial.</p>
<h2 dir="auto">Diagrams</h2>
<p dir="auto">N/A</p>
<h2 dir="auto">Alternatives</h2>
<p dir="auto">There isn't a way to avoid name collisions in a simple way because Celery decided to namesquat randomly. Separate file maybe. The lack of configuration option owner prefix can't really be worked around trivially.</p>