Best practices on upgrading cassandra
<p>I am getting errors from pyspark connecting to cassandra because it appears I am using a too old a cassandra:</p>

<pre><code>[idf@node1 python]$ nodetool -h localhost version
ReleaseVersion: 2.0.17
[idf@node1 python]$ 
</code></pre>

<p>[idf@node1 cassandra]$ java --version
Unrecognized option: --version
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.</p>

<pre><code>[idf@node1 cassandra]$ java -version
java version "1.8.0_45"
Java(TM) SE Runtime Environment (build 1.8.0_45-b14)
Java HotSpot(TM) 64-Bit Server VM (build 25.45-b02, mixed mode)
[idf@node1 cassandra]$ 
</code></pre>

<p>I want to upgrade to the latest version. However, I have already collected quite a bit of data and I don't want to lose it. I am using CentOS 7.2 with a single cassandra node. My questions are, </p>

<ul>
<li>where is the cassandra data stored on the local file system</li>
<li>is it correct to assume that I can compress this directory and move it?</li>
</ul>

<p>Then once I have the data backed up, what is the correct way to upgrade cassandra? Is it </p>

<ul>
<li>remove old version completely</li>
<li>install new version</li>
<li>copy data back</li>
</ul>

<p>What is the best practice to do this?</p>