I am wondering if something like this: http://esri.github.io/gis-tools-for-hadoop/ exists but for QGIS. Or if these tools be adapted for QGIS.
The GIS Tools for Hadoop read from and write to several standard and documented formats, including CSV, WKT, WKB, Esri GeoServices REST JSON, and GeoJSON. So with some effort it should be possible to use the GIS Tools for Hadoop with QGIS. In fact, there is indirect evidence that such has been done.
[Disclosure: I am a collaborator on the Esri GIS Tools for Hadoop.]