I want to generate alert at real time based on the incoming data. So everyone zeroed on in-memory concept. But confusion looms over whether to use Apache ignite or Apache Spark? Kindly suggest benefits of using one over other.
Spark and Ignite have some similarities but also some differences. These mostly correspond with your intended use.
Two different beasts.
Ignite looks to be from Grid Gain. Essentially open sourcing their product to get traction where I would assume the company would profit from selling support.
In terms of what it has to offer... it appears to be an in-memory shared distributed space. They appear to tie in to spark by allowing shared RDDs.
I'm not sure on how this would be applied to your desired. "I want to generate alert at real time based on the incoming data."
Real time is fungible and you don't really talk about what you mean by incoming data. Incoming how and where?
And you don't really describe what you mean by an 'alert'. Do you want to put a small electrical device that's in the IoT cloud so that whenever an event happens you can shock / alert the person that an event happened?
(Sorry, for the sarcasm, but you need to really provide more details before you can determine what tools to use.)
Retrieving data ...