I have a private blockchain (using Parity) where initially, all the nodes talk to each other, but over time (usually 9-18 hours) they lose connectivity until they all drop off and have zero peers. Once in a while they find each other again here and there - one of them at least. But it drops off again just as unexpectedly.

This happens after syncing, as sync takes less than the 9 hours.

If I use reserved peers it is a little better. Even those lose connectivity sometimes but it doesn't matter because this is not going to help with this particular project.

There are a total of 30 nodes in total.

All nodes are running on VPSes. All nodes have 30303 and 30303/udp open. Most nodes are on the same network.

1 Answer 1


Yes, you enable tracing on the node for the sync module, like that:

parity -l sync=trace

This will produce a lot of noise, but you will be able to see why nodes are talking to each other, or why not... :p

  • Is there a way to limit this output? It's way way way way way too fast to read. Also, when I do this I don't have the standard Parity display anymore. Also, how does this help me see why nodes are not talking to each other? I don't understand the output but I don't see anything that seems connected to the question.
    – stone.212
    Nov 22, 2017 at 7:26
  • I don't want to sound defeatest. Just looking for a glossary or some way of understanding how to interpret something like "New peer 3 (protocol: 2, network: 42, difficulty: Some(1582685615374142282722184319752859988882122687), latest:3d66…b294, genesis:b4c5…2cb9, snapshot:Some(4735000))"
    – stone.212
    Nov 22, 2017 at 8:41
  • Feel free to add the logs to the original question and I can help you looking into it.
    – q9f
    Nov 23, 2017 at 13:59
  • Thank you but the console "logs" produce about 10 pages of output every few minutes. And they happen all of the time, not only when connections begin or end. It might happen that a connection goes down when I happen to be near a computer, but it is more likely that I will not. And because the logs move so quickly, I have no way of finding them. My question is a request for debugging steps. If there are phrases within the logs that I should be searching for, that would make it feasible for me to use your answer to begin to create an answer to the question.
    – stone.212
    Nov 24, 2017 at 8:36
  • Maybe I should ask: exactly what logs do you want to see? I can start the logging when I initiate the blockchain. But it usually takes hours before the connections fail. Do you want one all of that? Do you want multiple nodes? I can send logs, but this output is so verbose that I don't know what you are suggesting exactly.
    – stone.212
    Nov 30, 2017 at 8:29

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.