Introduce a subsection "egress" under serverStatus "network" section.
The updated "network" section looks like :
network : {
egress :

{ bytesIn : Long("<num>"), bytesOut : Long("<num>"), physicalBytesIn : Long("<num>"), physicalBytesOut : Long("<num>"), numRequests : Long("<num>"), }

bytesIn : ...,
bytesOut : ....,
physicalBytesIn : ....,
physicalBytesOut : ....,
numSlowDNSOperations : ...,
numSlowSSLOperations : ...,
numRequests : ....,
...
}

Description of Linked Ticket

The metrics under serverStatus.network only account for the network traffic of ingress connections (see SERVER-6227). Extending the metrics to also include egress connections, those established by a mongo process, would help diagnostics and monitoring. This ticket requires the following:

• Defining new metrics (e.g., egress.physicalBytesOut and egress.physicalBytesIn) for egress traffic.
• Separating egress and ingress metrics in serverStatus.
• Creating a ticket to update the documentation for network metrics in serverStatus.