The DigiByte Node Crawler aggregates nodes from connectable public nodes. Using a highly modified version of bitcoinj, peers are connected to serially. Memory efficient, with a simple UI, the app is lightweight on nodes only executing a maximum of 23 commands before moving onto the next.
The app uses Bitcoin's getAddr command two query nodes for the list of other nodes that have connected. The app waits for 2 getAddr messages to be received before moving onto the next node. Only nodes that are open, meaning their p2p port is accepting socket connections, are port of the open count. The app continuously attempt to open a socket, to the addresses provided port using a dedicated thread. Connections are only attempted to open nodes. The recents count are of addresses that have a timestamp of 8 hours ago or less.
The app successfully crawls the following blockchains: