[BUG] Re-registered peer not reflected until restart

[s8sato]

When a peer is registered, unregistered, and registered again to a network, the peer has to restart for the network to update.

OS and Environment

Linux, Docker Hub

GIT commit hash

27d9f85

Minimum working example / Steps to reproduce

See description on the test branch

Actual result

See description on the test branch

Expected result

See description on the test branch

Logs

See description on the test branch

Who can help to reproduce?

@s8sato

Notes

[aoyako]

Issue:

It seems that after unregistering, a peer is removed from the online_peers list, causing a loss of connection.
Peer restart helps because, during setup, the peer requests the genesis block from trusted peers.

Potential Solutions:

1. Add the peer to online_peers when it is registered.
   • This might break invariants on online_peers and cause delays if the registered peer is offline.
2. If a peer is not connected to anything, it should attempt to connect to trusted peers.
   • However, if trusted peers are also offline, the peer will remain unconnected.
3. Ignore this case.

My Opinion:
This issue may occur if a peer is mistakenly removed and then re-added.
Therefore, I find the first approach more favorable despite its risks.

[s8sato]

after unregistering, a peer is removed from the online_peers list, causing a loss of connection

I think this is an expected behavior. The issue would be the difference between the first and subsequent registrations

1. Add the peer to online_peers when it is registered.

I think p2p already tries to do this according to the world having the new peer

[aoyako]

I was wrong originally. Method 1 won't apply because peer registration takes only a key, not the actual address of the peer. In that case, option 2 is viable.

[s8sato]

option 2 is viable

After being unregistered and loosing online peers, I expect, the peer should try to connect to other peers stored in the world, and after being re-registered it should restore connections. But the actual behavior doesn't seem to be that