60c8257c3c
In this commit, we modify the msgStream struct to ensure that it has a cap at which it’ll continue to buffer messages. Currently we have two msgStream structs per peer: the first for the discovery messages, and the second for any messages that modify channel state. Due to inefficiencies in the current protocol for reconciling graph state upon connection (just dump the entire damn thing), when a node first starts up, this can lead to very high memory usage as all peers will concurrently send their initial message dump which can be in the thousands of messages on testate. Our fix is simple: make the message stream into a _bounded_ message stream. The newMsgStream function now has a new argument: bufSize. Internally, we’ll take this bufSize and create more or less an internal semaphore for the producer. Each time the producer gets a new message, it’ll try and read an item from the channel. If the queue still has size, then this will succeed immediately. If not, then we’ll block until the consumer actually finishes processing a message and then signals by sending a new item into the channel. We choose an initial value of 1000. This was chosen as there’s already a max limit of outstanding adds on the commitment, and a value of 1000 should allow any incoming messages to be safely flushed and processed by the gossiper.
Lightning Network Daemon
The Lightning Network Daemon (lnd) - is a complete implementation of a
Lightning Network node and currently deployed on
testnet3 - the Bitcoin Test Network. lnd has several pluggable back-end
chain services including btcd (a
full-node) and neutrino (a new
experimental light client). The project's codebase uses the
btcsuite set of Bitcoin libraries, and also
exports a large set of isolated re-usable Lightning Network related libraries
within it. In the current state lnd is capable of:
- Creating channels.
- Closing channels.
- Completely managing all channel states (including the exceptional ones!).
- Maintaining a fully authenticated+validated channel graph.
- Performing path finding within the network, passively forwarding incoming payments.
- Sending outgoing onion-encrypted payments through the network.
- Updating advertised fee schedules.
- Automatic channel management (
autopilot).
Lightning Network Specification Compliance
lnd fully conforms to the Lightning Network specification
(BOLTs). BOLT stands for:
Basic of Lightning Technologies. The specifications are currently being drafted
by several groups of implementers based around the world including the
developers of lnd. The set of specification documents as well as our
implementation of the specification are still a work-in-progress. With that
said, the current status of lnd's BOLT compliance is:
- BOLT 1: Base Protocol
- BOLT 2: Peer Protocol for Channel Management
- BOLT 3: Bitcoin Transaction and Script Formats
- BOLT 4: Onion Routing Protocol
- BOLT 5: Recommendations for On-chain Transaction Handling
- BOLT 7: P2P Node and Channel Discovery
- BOLT 8: Encrypted and Authenticated Transport
- BOLT 9: Assigned Feature Flags
- BOLT 10: DNS Bootstrap and Assisted Node Location
- BOLT 11: Invoice Protocol for Lightning Payments
Developer Resources
The daemon has been designed to be as developer friendly as possible in order
to facilitate application development on top of lnd. Two primary RPC
interfaces are exported: an HTTP REST API, and a gRPC
service. The exported API's are not yet stable, so be warned: they may change
drastically in the near future.
An automatically generated set of documentation for the RPC APIs can be found at api.lightning.community. A set of developer resources including talks, articles, and example applications can be found at: dev.lightning.community.
Finally, we also have an active
Slack
where protocol developers, application developers, testers and users gather to
discuss various aspects of lnd and also Lightning in general.
Installation
In order to build from source, please see the installation instructions.
IRC
- irc.freenode.net
- channel #lnd
- webchat