Why does SparkContext randomly close, and how do you restart it from Zeppelin?
<p>I am working in Zeppelin writing spark-sql queries and sometimes I suddenly start getting this error (after not changing code):</p>

<pre><code>Cannot call methods on a stopped SparkContext.
</code></pre>

<p>Then the output says further down:</p>

<pre><code>The currently active SparkContext was created at:

(No active SparkContext.)
</code></pre>

<p>This obviously doesn't make sense.  Is this a bug in Zeppelin?  Or am I doing something wrong?  How can I restart the SparkContext?</p>

<p>Thank you</p>