Parameters

server

An array containing the basic information about the server that was picked.

key	value
hash	server hash, example: localhost:27017;-;X;56052
type	Node type (primary/secondary/mongos/arbiter): 2
max_bson_size	The maximum BSON Size over the wire this node accepts: 16777216
max_message_size	The maximum Message Size over the wire this node accepts: 48000000
request_id	The request identifier for this message: 42

writeOptions

key	value
ordered	boolean, if the operation (in case of batch operation) must be executed sequentually (ordered=true)
writeConcern	An array of writeConcern options (see below)

writeConcern array values

key	value
fsync	boolean, force flushing to disk before returning
j	boolean, force journal write before returning
wtimeout	integer, milliseconds, maximum time the primary is allowed to wait to verify replication
w	integer=server count, or string=replication-tag

deleteOptions

key	value
limit	integer, 1 or 0. If 0, delete all matching documents.
q	Array, the search criteria

protocolOptions

key	value
message_length	The total size (in bytes) of the encoded message being sent over the wire
request_id	The request identifier for this message: 42
namespace	The MongoDB namespace used for the protocol message dbname.collectionname