Yes, per “It would be acceptable or even desirable if the DHT I am searching consists exclusively of instances of my app.”, you want to not be connected to the public libp2p network. So, you should use your own bootstrap nodes and webrtc star server, so that your application peers only discover each other.
The DHT needs to have at least one entry in its routing table to start. This way, at least one bootstrap node should be running the DHT protocol. Once you connect to the bootstrap nodes, the identify protocol will kick in and peers will exchange the protocols they support. With that, a DHT protocol stream is created between both parties and they are now part of an overlay network. After this, if you have the random walk discovery enabled in the config, your node will periodically try to find other nodes via the DHT peer it already knows. Once new peers are discovered, the node might connect to them until the connection manager gets to its maximum threshold.
Yes! So, grabbing the above explanation, the flow is:
- Connection established
- Identify protocol starts and peers exchange their known protocols
- Peer Protocols are stored in the PeerStore’s ProtoBook
- Libp2p topologies (DHT, pubsub are some of the topologies we have) will verify if the new “discovered” protocols for a peer include their protocols. If they have, the topology
onConnecthandler is triggered.
- The protocol implements the
onConnectlogic. While this is not mandatory to happen, both DHT and pubsub open streams on their protocol to these peers and they become part of the DHT/pubsub topology automatically.
You can use the libp2p topology to help with this. You can take a look on the DHT network. This does not solve the disconnect+poison.
So, with the latest comment you might need to explore making
autoDial to be false and manually trigger dials (if you use your own network with own bootstraps and no connectivity to the public network this should not be necessary, right?). With this, when peers are discovered (you can listen on the discovery event), you can manually dial them if you don’t have any information for them in the ProtoBook (be aware that peer protocols might also change over time) you can dial them and listen for the events on protocols change. When the protocol event is triggered, if your protocol is not there, you can “poison” the peer (use the metadataBook within the peerStore for this). So, you can add logic in your decision to dial on discovery the metadataBook check for poison.
FYI in this discovery+connection flows, we will be working on improving the developer experience for this soon libp2p/js-libp2p#744. You can follow it and also provide your input according to your experience while working on this. We want to get rid of the autoDial and to enable libp2p to become more intelligent on the peers it should connect to. This should include essential peers like rendezvous servers, relays, protocol peers (according to the topology configuration) and distance.