#Definitions

This page defines terms like snapshot, difference between two snapshots and more. Additionally it clarifies edge case handling.

#Snapshot

A snapshot of the Bitcoin Lightning Network is a collection of gossip messages (Lightning Messages of type 256, 257, 258) that where valid at the given timestamp.

The term valid means that the information of the gossip message can be found in the topology of the Lightning Network at the given timestamp.

#Difference between two snapshots

A difference between two snapshots is the set of gossip messages that have been published between the given start_timestamp and end_timestamp.

#Node information

Gets all node_announcement, channel_announcement and channel_update messages that contain the node_id.

#Channel information

Gets all channel_announcement and channel_update messages for a given scid.

#Edge cases

The gossip protocol of the Bitcoin Lightning Network is lossy. We might not gather every gossip message. Here is a list of certain edge cases and how the ln-history plaform reacts. In general we try to collect as much as possible

#Collected node_announcement for a node without channels

Add new row to nodes_raw_gossip table with the timestamp of the node_announcement message. Create a new rows in nodes table with the given node_id and set the from_timestamp and last_seen to the timestamp of the node_announcement message.

#Collected channel_announcement with one (or two) node_ids that were not previously announced

Create one (or two) new rows to the nodes table with the given node_id set the from_timestamp and last_seen to the timestamp of the channel_announcement message. DO NOT create a row in the nodes_raw_gossip table. Create a new row in the channels table and set timestamp_from to the timestamp of the channel_announcement message.

#Collected channel_update message for a channel without previously collected channel_announcement

Split the scid into block_height, tx_idx. out_idx. Check the Bitcoin Blockchain if the transaction is a valid channel_announcement-transaction.

• If it is: Add new row to channels table where the timestamp of the block at the given block_height is the from_timestamp. Add channel_update to channel_updates table.

• If it is NOT: Ignore the channel_update

#Disclaimer

Through out this project I have used the term the (Bitcoin) Lightning Network. To be very exact this is confusing. There is not the Lightning Network, technically multiple Lightning Networks could exists in parallel. Some Bitcoin nodes could connect themselves using the Lightning protocol and have their own Lightning Network.

In reality there is - to say the least - a "dominant" Lightning Network with thousands of nodes and channels. When reading the (Bitcoin) Lightning Network, think about this Lightning Network.