Let me start apologizing. This is a very common question but I'm not very familiar with Hadoop.
I'm starting to work on a project that requires a very reliable data storage. I love ES and I would choose ES over MongoDB for any project but with such strict requirements I see myself forced to use an RDBMS solution.
Could ES+Hadoop be a viable alternative? My understanding is that HDFS is pretty reliable, close to a RDBMS (but slow for "real-time" applications). There are security features in this project that guarantee data synchronization across the two systems (ES and Hadoop)?