What does channel num_updates mean?

1

Some LND wallets provide a channel's "Number of Updates". Here's an example from Zap Desktop:

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The LND gRPC API Channel Reference cites a property called num_updates. The description of this field is not very informative:

The total number of updates conducted within this channel.

What specifically is a channel update?

J.P.

Posted 2019-04-19T04:44:01.380

Reputation: 11

Answers

1

For some reason stackoverflow has a 50 reputation limit on comments, so I must use the answer box to point out that Karlo's answer is not correct - or at least does not tell the whole story. I understand that this is not the correct use for the answer box, blame stackoverflow's poorly thought out reputation limits.

I have a node with a few (outgoing) channels, have not spent a single satoshi with it yet. So the "remote balance" of the channels has always been 0, in other words there have been no balance updates. Yet the number of updates in the channels is non-zero.

kekcoin

Posted 2019-04-19T04:44:01.380

Reputation: 11

Updates can include changes to (on-chain) transaction fees. By default num_updates will also always be >0 if the channel is fully established, because there is a required update between the channel's initial funding and the funds being locked.Mark H 2019-04-19T12:56:26.640

The num_updates metrics are also not 1, closer to 10.kekcoin 2019-04-19T13:45:46.847

0

When a payment is done, the channel states update.

Your channel might start with a balance of 100 000. This is all on your side.

Then a payment is done of 10 000. The channel gets updated: your side has 90 000, the remote side has 10 000.

Any update, or: "payment" beyond this point is an update.

Karlo

Posted 2019-04-19T04:44:01.380

Reputation: 101

0

A channel update can be a new payment routed via the channel (balances need to get update so a new commitment is generate), new fees negotiation (fee uncooperative channel closure), a request of CSV change by the other party (value in which your node will be able to sweep funds if you close the channel in a uncooperative way) among others...

João de Almeida

Posted 2019-04-19T04:44:01.380

Reputation: 1