multiple map and reduce worker
Fix memory leak on grok, add memory profiling options, improve logging
Add new time format detection, add some statistic at the end run execution
Add benchmark to test if reading multiple file at once is faster.
Parameterize number of mapper & reducer, add more logging
move parsing to mapper function
Add function for grok to output the pcre compiled pattern
Add runner script, reenable grok fix memory dealocation.