> ## Documentation Index
> Fetch the complete documentation index at: https://docs.springtail.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Ingest Nodes

The ingest nodes are responsible for synchronizing the replica data with the primary database data.  There are two different key states of operation -- `INITIALIZE` and `RUNNING`.

# Initialization

When the system is started in the `INITIALIZE` state, the ingest node performs the following actions:

1. Connect to the logical replication slot and begin capturing the stream of mutations.
2. Capture the set of tables to synchronize and copy them to the replica storage.
3. Play forward any in-flight changes since the table snapshots were captured to ensure we have a consistent snapshot of the entire system.
4. Move into the RUNNING state.

# Running

When the system is started in the `RUNNING` state, the ingest node performs the following actions:

1. Connect to the logical replication slot and begin capturing the stream of mutations.
2. Perform any [recovery](/recovery) required to bring the system to a consistent snapshot.
3. Play forward any changes recorded into the local log since recovery began.
4. Move into a steady-state operation of [processing messages](/message-processing).