High CPU usage with node

Hi aws team!

I'm running the KCL client for reading 10 shards.
It seems like the for some simple log operations, each process take up to [45% cpu usage](https://www.dropbox.com/s/1pj4ajuzc5f29hf/Screenshot%202015-08-25%2010.33.08.png?dl=0) on a m3.xlarge. I was wondering if that was normal, or if I'm missing anything ?

Thank you for your insights

The report concerns the Node.js KCL client reading 10 shards, but names no files or tests. Start by reproducing the workload on an m3.xlarge and profiling CPU during the log operations; done means determining whether the usage is expected or documenting a confirmed cause and targeted fix.

Written by the indexing model from the issue text.