Announcing lndmon v0.2.
Carla Kirk-Cohen
Hi list!
Today we’re excited to announce v0.2.0 of lndmon, our drop-in solution for monitoring lnd
nodes. The main feature in this release is a new routing dashboard, which aims to provide
routing node operators with better insight into their node’s activity.
This dashboard uses lnd’s SubscribeHtlcEvents api, which surfaces information about every HTLC
that your node has forwarded, including your own sends and receives. The dashboard includes a
dropdown filter which can be used to toggle between sends from, receives to, and forwards
through your node. There is a lot of information packed into this dash, so I’d like to use this post to
introduce some of the information we’re surfacing.
Channel Utilization
The routing dashboard displays bar graphs that indicate the amount of incoming and outgoing traffic
each channel has forwarded. Knowing which channels your node is using for incoming and outgoing
HTLCs is useful for managing your channel liquidity.
For example, if you’re receiving a lot of successful inbound HTLCs on a channel, it may be a good
idea to Loop Out over that channel to replenish your inbound so that you can continue to receive.
Likewise, if you’re processing a lot of outgoing HTLCs with a certain peer, you may want to investigate
opening another channel to service the high volume in that direction, or Loop In to ensure that you’re
able to keep sending payments out over it.
Failure Reasons
The new dashboard also surfaces the failure reasons for failed HTLCs. Knowing why your forwards,
sends, or receives are failing can provide actionable information about how to improve your success
rate.
The following failure reasons are of particular interest when operating a routing node:
Insufficient Balance: if a payment fails with insufficient balance, your node did not have sufficient
outgoing balance to forward the payment to the next peer along the route. This may happen for your
own payments, or for payments forwarded through you. More actively managing your outgoing
liquidity will help reduce these failures.
Circular Route: lnd disallows nodes to forward a payment through your node on the same channel,
because this indicates that a payment is needlessly routing through your node. If you see failures of
this nature, it may indicate that somebody is trying to lock up your node’s liquidity. lnd’s
HtlcInterceptor can be used to apply restrictions on nodes attempting to send these circular payments
through your node.
Failed back: it is also possible that a forward through your node fails further down the route, rather
than at your own node. In this case, we do not know the failure reason, so the failure will simply be
tracked as “failed back”.
We will be looking to more actively develop this project in the new year, and are looking at including
features like amount-based graphs for the routing dashboard, multi-node support and more. If these
would be of use to you, or your organization, please let us know on this list or via the usual avenues
Happy holidays, happy ATH!
Carla