add pingInterval same as used in ref C# implementation with the same logic
add pingTimeout which is used to check whether pong received. If not -- drop the peer.
add pingLimit which is hardcoded to 4 in TCPPeer. It's limit for unsuccessful ping/pong calls (where pong wasn't received in pingTimeout interval)
It wasn't actually requesting transactions but rather sending an inventory
message telling everyone that we have them which is completely wrong and
easily leads to ChangeView that could be avoided.
Only request headers from the other peer if his height is bigger than
ours. Otherwise we routinely ask 0-height newcomers for some random headers
that they know nothing about.
This one is essential for the consensus nodes as otherwise they won't give out
the blocks they generate making their generation almost useless. It also makes
our networking part more complete.
We have a race between reader and writer goroutines for the same connection
that leads to handshake failures when reader is faster to read the incoming
version (and try to reply to it) than writer is to write our own Version:
WARN[0000] peer disconnected addr="172.200.0.4:20334" peerCount=5 reason="invalid handshake: tried to send VersionAck, but didn't send Version yet
Fix it by moving Version sending before the reader loop starts.
Our node didn't respect the MaxPeers setting, fix it with a drop of random
connection when this limit is reached (to give a chance for newcomers to
communicate), but also introduce AttemptConnPeers setting to tune the number
of attempted connections.
This also raises the default MaxPeers for testnet/mainnet to 100, because
neo-go nodes love making friends.
It's bogus and no other node implementation has anything like that. It fires
up for no good reason in the case when some other node connects to us and it
obviously doesn't use its listening port for it.
In the very specific case when the list of headers received is exactly one
block ahead of the chain of full blocks requestBlocks() failed to generate
request to get the next full block.
This one will replace blockCache in Blockchain itself as it can and should be
external from it. The idea is that we only feed successive blocks into the
Blockchain and it only stores valid proper Blockchain and nothing else.
...and don't try to connect to the nodes we're already connected to.
Before this change we had a problem of discoverer throwing away good valid
addresses just because they are already known which lead to pool draining over
time (as address reuse was basically forbidden and getaddr may not get enough
new nodes).
Queuing one message is not reliable enough, the peer that gets it can fail to
actually make a request, so make this queue a bit deeper to have a higher
chance of success.
This makes writer side handle errors properly and fixes communication between
reader and writer goroutine to always correctly unregister the peer. This is
especially important for the case where error occurs before handshake
completes as in this case we don't even have goroutine in startProtocol()
running.
