18 karma · joined July 2, 2014
Using stream processing framework like Storm maybe fine when you are running exactly the same code for both real time and batch but it breakdown in more complex cases when code is not exactly the same. Let say we need to calculate Top K trending item from now to last 30 mins, One day and One week. We also know that simple count will always make socks and underwear trend for an ecom shops and Justin Bieber and Lady Gaga for twitter(http://goo.gl/1SColQ). So we use count min sketch for realtime and a sligtly more complex ML algorithm for batch using Hadoop and merge the result in the end. IMO, training and running complex ML is not currently feasible on Streaming Frameworks we have today to use them for both realtime and batch.
edited for typos.