Apache Spark vs Apache Ignite
<p>Currently I'm studying Apache spark and Apache ignite frameworks. </p>

<p>Some principle differences between them are described in this article <a href="http://drcos.boudnik.org/2015/04/apache-ignite-vs-apache-spark.html" rel="noreferrer">ignite vs spark</a> But I realized that I still don't understand their purposes. </p>

<p>I mean for which problems spark more preferable than ignite and vice versa?</p>