js-chat does not receive always messages after starting

[D4nte]

Problem

After a start when connecting to the fleet, sometimes js-chat does not receive any messages but is able to send messages. This is only happen when connecting to a remote node, e.g.:

npm run chat:start --scripts-prepend-node-path=auto -- --staticNode /ip4/134.209.139.210/tcp/30303/p2p/16Uiu2HAmPLe7Mzm8TsYUubgCAW1aJoeFScxrLj8ppHFivPo97bUZ --listenAddr /ip4/0.0.0.0/tcp/55123

Details

A sleep seems to have help (TODO: paste link) as it may be due to timing issues when starting the node.

A possible scenario could be:

1. chat dials remote node
2. Remote node subscribe to default waku topic before identify protocol is finished, chat drop subscription because it does not know remote node support waku relay protocol *
3. identify protocol finishes
4. chat sends subscription to remote node but remote node does not graft chat node to mesh topic
5. Remote node does not forward messages to chat node

The reason of 4 could be due to:

• Does not GRAFT after receiving subscription vacp2p/nim-libp2p#554
• wakurelay, and underlying gossipsub, is never started nwaku#445

• This is a non-verified hypothesis.

Solution

• Monitor if the issue still occurs once wakurelay, and underlying gossipsub, is never started nwaku#445 is resolved
• If it does, investigate step 2 to understand why chat node does not add remote node to fanout map when receiving this subscribe (by having remote node in fanout map then chat should add remote node to mesh when doing step 4).