status-go/geth/peers/README.md

Peer pool signals

Peer pool sends 3 types of signals.

Discovery started signal will be sent once discovery server is started. And every time node will have to re-start discovery server because peer number dropped too low.

{
  "type": "discovery.started",
  "event": null
}

Discovery stopped signal will be sent once discovery found max limit of peers for every registered topic.

{
  "type": "discovery.stopped",
  "event": null
}

Discovery summary signal will be sent every time new peer is added or removed from a cluster. It will contain a map with capability as a key and total numbers of peers with that capability as a value.

{
  "type": "discovery.summary",
  "event": {
    "shh/6": 1
  }
}

Or if we don't have any peers:

{
  "type": "discovery.summary",
  "event": {}
}