<h2 dir="auto">Checklist</h2>
<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 <code class="notranslate">celery -A proj report</code> in the issue.<br>
(if you are not able to do this, then at least specify the Celery<br>
version affected).</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have verified that the issue exists against the <code class="notranslate">master</code> branch of Celery.</li>
</ul>
<p dir="auto">Running from commit <a class="commit-link" data-hovercard-type="commit" data-hovercard-url="https://github.com/celery/celery/commit/21baef53c39bc1909fd6eee9a2a20e6ce851e88c/hovercard" href="https://github.com/celery/celery/commit/21baef53c39bc1909fd6eee9a2a20e6ce851e88c"><tt>21baef5</tt></a>. Report cannot be run since nothing is able to start.</p>
<h2 dir="auto">Steps to reproduce</h2>
<p dir="auto">Create a minimal worker, but use a backend URI that specifies a failover set <a href="http://docs.celeryproject.org/en/latest/getting-started/brokers/redis.html#configuration" rel="nofollow">as specified by the documentation</a></p>
<p dir="auto">Hostnames do not matter since no connection attempt will be made</p>
<div class="highlight highlight-source-python notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="from celery import Celery

c = Celery(
    __name__,
    broker=&quot;sentinel://host1:8080;sentinel://host2:8080;sentinel://host3:8080&quot;,
    backend=&quot;sentinel://host1:8080;sentinel://host2:8080;sentinel://host3:8080&quot;
)


@c.task
def add(x, y):
    return x + y"><pre class="notranslate"><span class="pl-k">from</span> <span class="pl-s1">celery</span> <span class="pl-k">import</span> <span class="pl-v">Celery</span>

<span class="pl-s1">c</span> <span class="pl-c1">=</span> <span class="pl-v">Celery</span>(
    <span class="pl-s1">__name__</span>,
    <span class="pl-s1">broker</span><span class="pl-c1">=</span><span class="pl-s">"sentinel://host1:8080;sentinel://host2:8080;sentinel://host3:8080"</span>,
    <span class="pl-s1">backend</span><span class="pl-c1">=</span><span class="pl-s">"sentinel://host1:8080;sentinel://host2:8080;sentinel://host3:8080"</span>
)


<span class="pl-en">@<span class="pl-s1">c</span>.<span class="pl-s1">task</span></span>
<span class="pl-k">def</span> <span class="pl-en">add</span>(<span class="pl-s1">x</span>, <span class="pl-s1">y</span>):
    <span class="pl-k">return</span> <span class="pl-s1">x</span> <span class="pl-c1">+</span> <span class="pl-s1">y</span></pre></div>
<p dir="auto">Run as normal with <code class="notranslate">celery -A minimal_celery worker</code></p>
<h2 dir="auto">Expected behavior</h2>
<p dir="auto">Worker loads and starts as normal</p>
<h2 dir="auto">Actual behavior</h2>
<p dir="auto">Celery banner formatter attempts to parse the string as a single URI and cannot extract the port number</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="[2018-10-16 17:47:25,407: CRITICAL/MainProcess] Unrecoverable error: ValueError(&quot;invalid literal for int() with base 10: '8080;sentinel:'&quot;,)
Traceback (most recent call last):
  File &quot;ENV/celery/worker/worker.py&quot;, line 205, in start
    self.blueprint.start(self)
  File &quot;ENV/celery/bootsteps.py&quot;, line 115, in start
    self.on_start()
  File &quot;ENV/celery/apps/worker.py&quot;, line 139, in on_start
    self.emit_banner()
  File &quot;ENV/celery/apps/worker.py&quot;, line 154, in emit_banner
    ' \n', self.startup_info(artlines=not use_image))),
  File &quot;ENV/celery/apps/worker.py&quot;, line 217, in startup_info
    results=self.app.backend.as_uri(),
  File &quot;ENV/celery/backends/base.py&quot;, line 135, in as_uri
    url = maybe_sanitize_url(self.url or '')
  File &quot;ENV/kombu/utils/url.py&quot;, line 92, in maybe_sanitize_url
    return sanitize_url(url, mask)
  File &quot;ENV/kombu/utils/url.py&quot;, line 85, in sanitize_url
    return as_url(*_parse_url(url), sanitize=True, mask=mask)
  File &quot;ENV/kombu/utils/url.py&quot;, line 52, in url_to_parts
    parts.port,
  File &quot;/usr/lib64/python3.6/urllib/parse.py&quot;, line 169, in port
    port = int(port, 10)
ValueError: invalid literal for int() with base 10: '8080;sentinel:'"><pre class="notranslate"><code class="notranslate">[2018-10-16 17:47:25,407: CRITICAL/MainProcess] Unrecoverable error: ValueError("invalid literal for int() with base 10: '8080;sentinel:'",)
Traceback (most recent call last):
  File "ENV/celery/worker/worker.py", line 205, in start
    self.blueprint.start(self)
  File "ENV/celery/bootsteps.py", line 115, in start
    self.on_start()
  File "ENV/celery/apps/worker.py", line 139, in on_start
    self.emit_banner()
  File "ENV/celery/apps/worker.py", line 154, in emit_banner
    ' \n', self.startup_info(artlines=not use_image))),
  File "ENV/celery/apps/worker.py", line 217, in startup_info
    results=self.app.backend.as_uri(),
  File "ENV/celery/backends/base.py", line 135, in as_uri
    url = maybe_sanitize_url(self.url or '')
  File "ENV/kombu/utils/url.py", line 92, in maybe_sanitize_url
    return sanitize_url(url, mask)
  File "ENV/kombu/utils/url.py", line 85, in sanitize_url
    return as_url(*_parse_url(url), sanitize=True, mask=mask)
  File "ENV/kombu/utils/url.py", line 52, in url_to_parts
    parts.port,
  File "/usr/lib64/python3.6/urllib/parse.py", line 169, in port
    port = int(port, 10)
ValueError: invalid literal for int() with base 10: '8080;sentinel:'
</code></pre></div>
<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"> I have verified that the issue exists against the <code class="notranslate">master</code> branch of Celery.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> This has already been asked to the <a href="https://groups.google.com/forum/#!forum/celery-users" rel="nofollow">discussion group</a> first.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have read the relevant section in the<br>
<a href="http://docs.celeryproject.org/en/latest/contributing.html#other-bugs" rel="nofollow">contribution guide</a><br>
on reporting bugs.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have checked the <a href="https://github.com/celery/celery/issues?q=is%3Aissue+label%3A%22Issue+Type%3A+Bug+Report%22+-label%3A%22Category%3A+Documentation%22">issues list</a><br>
for similar or identical bug reports.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have checked the <a href="https://github.com/celery/celery/pulls?q=is%3Apr+label%3A%22PR+Type%3A+Bugfix%22+-label%3A%22Category%3A+Documentation%22">pull requests list</a><br>
for existing proposed fixes.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have checked the <a href="https://github.com/celery/celery/commits/master">commit log</a><br>
to find out if the bug was already fixed in the master branch.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have included all related issues and possible duplicate issues<br>
in this issue (If there are none, check this box anyway).</li>
</ul>
<h2 dir="auto">Mandatory Debugging Information</h2>
<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have included the output of <code class="notranslate">celery -A proj report</code> in the issue.<br>
(if you are not able to do this, then at least specify the Celery<br>
version affected).</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 <code class="notranslate">master</code> branch of Celery.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have included the contents of <code class="notranslate">pip freeze</code> in the issue.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have included all the versions of all the external dependencies required<br>
to reproduce this bug.</li>
</ul>
<h2 dir="auto">Optional Debugging Information</h2>

<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue on more than one Python version<br>
and/or implementation.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue on more than one message broker and/or<br>
result backend.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue on more than one version of the message<br>
broker and/or result backend.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue on more than one operating system.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> 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"> I have tried reproducing the issue with autoscaling, retries,<br>
ETA/Countdown &amp; rate limits disabled.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue after downgrading<br>
and/or upgrading Celery and its dependencies.</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>None</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=""><pre class="notranslate"><code class="notranslate"></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>: N/A or Unknown</li>
<li><strong>Minimal Celery Version</strong>: N/A or Unknown</li>
<li><strong>Minimal Kombu Version</strong>: N/A or Unknown</li>
<li><strong>Minimal Broker Version</strong>: N/A or Unknown</li>
<li><strong>Minimal Result Backend Version</strong>: N/A or Unknown</li>
<li><strong>Minimal OS and/or Kernel Version</strong>: N/A or Unknown</li>
<li><strong>Minimal Broker Client Version</strong>: N/A or Unknown</li>
<li><strong>Minimal Result Backend Client Version</strong>: N/A or Unknown</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=""><pre class="notranslate"><code class="notranslate"></code></pre></div>
<p dir="auto"></p>
</details>
<h3 dir="auto">Other Dependencies</h3>

<details>
<p dir="auto">
N/A
</p>
</details>
<h2 dir="auto">Minimally Reproducible Test Case</h2>

<details>
<p dir="auto">
</p><div class="highlight highlight-source-python notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content=""><pre class="notranslate"></pre></div>
<p dir="auto"></p>
</details>
<h1 dir="auto">Expected Behavior</h1>

<h1 dir="auto">Actual Behavior</h1>