node: Mitigate the impact of offline nodes over message propagation

[goshawk-3]

Summary

On having offline nodes for a longer period, we rely solely on kadcast redundancy factor for complete a msg broadcast. However, as suggested by @herr-seppia , we may consider updating the default bucket_ttl=30m in order to re-build the internal routing table more frequently, wiping out any offline/(not responding) peer.

Possible solution design or implementation

A more naive alternative could be to increase the redundancy factor in kadcast but this might increase the overall bandwidth significantly.

Additional context

A benchmark test should be performed to ensure that bucket_ttl change does not impact negatively overall performance.

[HDauven]

Consider changing it to 10 minutes even