My Hadoop is not efficient enough, what can I do ?

1. Review your memory configuration to maximize CPU utilisation
2. Review your YARN settings especially the Capacity Scheduler
3. Review your application design, parameter used, join strategy, file format

Of course with checking your ganglia / Ambari Metrics, voilà !

PS : For those who don't trust Multi-tenant Hadoop cluster, please call me ;-)

Hadoop Mini Clusters !

A nice project here to do some local test/development ! You can find others interesting projects in the Hortonworks gallery.