When set query processors will ignore the 'data' section in snapshots, which is used for serving cached copies.
Can be set in: collection.cfg
Specifies if push data sources running as query processors should download the document data from master. When set 'true' push data sources running as query processors will not be able to serve cached copies and will be unable to be promoted to an admin.
Default is to download the document data, so cached copies are available on the query processor.
If you don’t need cached copies of documents, and wish to save network load set: