[LU-5798] lnet: router buffering improvements

• Type: Improvement
• Resolution: Low Priority
• Priority: Minor
• Assignee: Isaac Huang (Inactive)
• Reporter: Isaac Huang (Inactive)

Description

There's a couple of ways to improve router buffering, especially under network congestion:

• When router is about to forward a message, it checks peer health information, and drops the message if the destination appears dead. In addition, we should also check the source of the message: if the source appears dead, the message should be dropped as well. This should be easy to implement.
• When under network congestion, a message can get queued indefinitely. It doesn't make sense to continue to buffer the message once the client/server has already aborted the RPC/bulk transfer. The tricky part is to figure out when to drop a queued message. This needs some investigation.