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All of these cases should end up calling lnet_finalize() API with the proper return code. lnet_finalize() will be the funnel where all these events shall be processed in a consistent manner. When the message is completed via lnet_complete_msg_locked(), the error is checked and the proper behavior as described above is executed.

Resend Window

The resend window is Resends are terminated when the peer_timeout , after which the peer is considered downfor a message expires.

Resends should also terminate if all local_nis and/or peer_nis are in bad health. New messages can still use paths that have less than optimal health.

A message is resent after the LND transmit deadline expires, or on failure return code. Both these paths are handled in the same manner, since a transmit deadline triggers a call to lnet_finalize(). Both inline and asynchronous errors also endup in lnet_finalize().

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The MD should be kept intact during the resend procedure. If there is a failure to resend then the MD should be released and message memory freed.

Patches

1. Add health values to local_ni
2. Modify selection to make use of local_ni health values.
3. Add explicit constraint in the selection to fail a re-send if no local_ni is in optimal health
4. Handle explicit port down/up events
5. Handle local interface failure on send and update health value then resend
6. Add health values to peer_ni
7. Add explicit constraint in the selection to fail a re-send if no remote_ni is in optimal health 
8. Handle remote interface failure on send and update health value then resend
9. Modify selection to make use of peer_ni health values.
10. Handle LND tx timeout due to being stuck on the queues for too long.
11. Handle LND tx timeout due to remote rejection
12. Handle LND tx timeout due to no tx completion

O2IBLND Detailed Discussion

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