input/mongodb collect counters from db.serverStatus().metrics.document

[m3nthal]

Feature Request

It would be great to collect counters from db.serverStatus().metrics.document that "reflects document access and modification patterns" from MongoDB Reference on db.serverStatus().metrics.document.

Proposal & Desired behavior

Collect data from db.serverStatus().metrics.document and generate the following metrics:

• documents_deleted_counter
• documents_inserted_counter
• documents_returned_counter
• documents_updated_counter

db.serverStatus().metrics.document example:

{
	"deleted": 431106,
	"inserted": 296993879,
	"returned": 557450993,
	"updated": 9053
}

Use case: [Why is this important (helps with prioritizing requests)]

While opcounter provides information on how many operations were performed, metrics.document gives the total number of documents that were operated on.