Dear ELK funs,
I am new to ELK, had watched online videos from elastic.co and installed logstash 2.2.2 elasticsearch 2.2.1 locally on a standalone server.
Learned from the videos, I know current version of logstash's performance has been improved because of the design change and elastic search could also be set up as a cluster.
So why other tools like redis or kafka are required here, could we just use purely ELK?
What could be the bottleneck of current version of ELK?
Also the terms like shipper, forwarder, broker and indexer are so confusing to me, I could only think of logstash -> elasticsearch -> kibana, where could I found more explanations of those terms?