logstash + elasticsearch are pretty amazing. however, if you are generating a high rate of log entries you may want to consider using mozilla hekad instead (http://hekad.readthedocs.org/en/latest/). on our servers logstash was running around 20% CPU during quite periods while hekad was running around 1-2% CPU. while during busy periods i think logstash was going up to 100% CPU while hekad was sitting around 20-30% CPU.
hekad is written in go which compiles down to native code while logstash is written in jruby which is not the most performant runtime.
hekad is written in go which compiles down to native code while logstash is written in jruby which is not the most performant runtime.