sliding Top N window

Good day, I have a following task: a stream of “page vies” coming to kafka topic. Each view contains list of product Ids from a visited page. The task: to have in “real time” Top N product. I am interested in some solution that would require minimum intermediate writes … So need to build a

Unsupported major.minor version 51.0

I found some discussions online, but it all cpome to advice to use JDF 1.7 (or 1.8). Well, I use JDK 1.7 on OS X Yosemite . Both java –verion // java version 1.7.0_80 Java(TM) SE Runtime Environment (build 1.7.0_80-b15) Java HotSpot(TM) 64-Bit Server VM (build 24.80-b11, mixed mode) and echo

Can't build Spark 1.3

\ I downloaded the latest Spark (1.3.) from github. Then I tried to build it. First for scala 2.10 (and hadoop 2.4): build/mvn -Pyarn -Phadoop-2.4 -Dhadoop.version=2.4.0 -DskipTests clean package That resulted in hangup after printing bunch of line like [INFO] Dependency-reduced POM written at