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1. LocalState - set of committed transactions prior to a moment .In Ignite LocalState is committed by writing ConsistentCutStartRecord into WAL. (WAL).
2. Message - transaction message, it is sent after changing LocalState on sending node, and it changes LocalState on receiving node after delivering
   1. In Ignite such messages are FinishRequest for 2PC, PrepareResponse for 1PC.
3. Channel - unidirectional connection between two Ignite nodes, where messages is sent (Communication SPI).
4. ChannelState - for single channel it's a set of messages that was sent (changed LocalState of sending node), but not received yet (hasn't changed LocalState of receiving node).
   1. In Ignite we can think that incoming ChannelState is represented by active transactions in PREPARING+ state (the Message might be sent by other nodes, but isn't received yet).
5. GlobalSnapshot - set consist of (LocalState and ChannelState for every incoming channel) for every node.
   1. In Ignite the snapshot is represented with 2 WAL records (ConsistentCutStartRecord commits the LocalState, ConsistentCutFinishRecord describes the ChannelState).
6. Marker - mark that piggy backs on the Message, and notifies a node about running snapshot.
   1. In Ignite ConsistentCutMarkerMessage is used.

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