phillro/node-elasticsearch-client — pull request #97 by hmalphettes (2013-07-07 21:56:35+00:00)
Title: NGinx require "Content-Length: 0" on some requests.

When elasticsearch is proxied by nginx some request requires an extra "Content-Length: 0" to get through.
See others reporting that issue as recently as April 2013
https://drupal.org/node/1959248

I faced this once I started to run elasticsearch as setup by cookbook-elasticsearch.

Thanks for your attention.