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  <div class="section" id="retrying-tasks">
<h1>Retrying Tasks<a class="headerlink" href="#retrying-tasks" title="Permalink to this headline">¶</a></h1>
<div class="section" id="retrying-a-task-if-something-fails">
<h2>Retrying a task if something fails<a class="headerlink" href="#retrying-a-task-if-something-fails" title="Permalink to this headline">¶</a></h2>
<p>Simply use <a title="celery.task.base.Task.retry" class="reference external" href="../reference/celery.task.base.html#celery.task.base.Task.retry"><tt class="xref docutils literal"><span class="pre">celery.task.base.Task.retry()</span></tt></a> to re-sent the task, it will
do the right thing, and respect the <a title="celery.task.base.Task.max_retries" class="reference external" href="../reference/celery.task.base.html#celery.task.base.Task.max_retries"><tt class="xref docutils literal"><span class="pre">celery.task.base.Task.max_retries</span></tt></a>
attribute.</p>
<div class="highlight-python"><pre>class SendTwitterStatusTask(Task):

    def run(self, oauth, tweet, \*\*kwargs):
        try:
            twitter = Twitter(oauth)
            twitter.update_status(tweet)
        except (Twitter.FailWhaleError, Twitter.LoginError), exc:
            self.retry(args=[oauth, tweet], kwargs=\*\*kwargs, exc=exc)</pre>
</div>
<p>Here we used the <tt class="docutils literal"><span class="pre">exc</span></tt> argument to pass the current exception to
<a title="celery.task.base.Task.retry" class="reference external" href="../reference/celery.task.base.html#celery.task.base.Task.retry"><tt class="xref docutils literal"><span class="pre">celery.task.base.Task.retry()</span></tt></a>. At each step of the retry this exception
is available as the tombstone (result) of the task, when
<a title="celery.task.base.Task.max_retries" class="reference external" href="../reference/celery.task.base.html#celery.task.base.Task.max_retries"><tt class="xref docutils literal"><span class="pre">celery.task.base.Task.max_retries</span></tt></a> has been exceeded this is the exception
raised. However, if an <tt class="docutils literal"><span class="pre">exc</span></tt> argument is not provided the
<a title="celery.task.base.RetryTaskError" class="reference external" href="../reference/celery.task.base.html#celery.task.base.RetryTaskError"><tt class="xref docutils literal"><span class="pre">celery.task.base.RetryTaskError</span></tt></a> exception is raised instead.</p>
</div>
<div class="section" id="setting-a-custom-delay-for-retries">
<h2>Setting a custom delay for retries.<a class="headerlink" href="#setting-a-custom-delay-for-retries" title="Permalink to this headline">¶</a></h2>
<p>The default countdown is in the tasks
<a title="celery.task.base.Task.default_retry_delay" class="reference external" href="../reference/celery.task.base.html#celery.task.base.Task.default_retry_delay"><tt class="xref docutils literal"><span class="pre">celery.task.base.Task.default_retry_delay</span></tt></a> attribute, which by
default is set to 3 minutes.</p>
<p>You can also provide the <tt class="docutils literal"><span class="pre">countdown</span></tt> argument to
<a title="celery.task.base.Task.retry" class="reference external" href="../reference/celery.task.base.html#celery.task.base.Task.retry"><tt class="xref docutils literal"><span class="pre">celery.task.base.Task.retry()</span></tt></a> to override this default.</p>
<div class="highlight-python"><pre>class MyTask(Task):
    default_retry_delay = 30 * 60 # retry in 30 minutes

    def run(self, x, y, \*\*kwargs):
        try:
            ...
        except Exception, exc:
            self.retry([x, y], \*\*kwargs, exc=exc,
                       countdown=60 # override the default and
                                    # retry in 1 minute</pre>
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            <ul>
<li><a class="reference external" href="">Retrying Tasks</a><ul>
<li><a class="reference external" href="#retrying-a-task-if-something-fails">Retrying a task if something fails</a></li>
<li><a class="reference external" href="#setting-a-custom-delay-for-retries">Setting a custom delay for retries.</a></li>
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