# Raft Basic Test Scenario

This directory contains a basic test setup for the Raft cluster with 4 nodes.

## Scenario Description

- **Cluster Setup**:
    - **Initial Cluster**: Node 1 and Node 2 form the initial cluster.
    - **Dynamic Members**: Node 3 and Node 4 are started as standalone nodes and can be added to the cluster dynamically using `node add`.
- **Configuration**:
    - **Log Compaction**: Disabled (`LogCompactionEnabled = false`). The binary log will grow indefinitely.
    - **Memory**: Only keys and metadata are cached in memory. Values are stored on disk (default engine behavior).
- **Data Directory**: `./data/node{1..4}`

## Setup and Usage

### 1. Start Nodes

Open 4 separate terminals and run the following commands:

**Terminal 1 (Node 1):**
```bash
cd example/basic/node1
go run main.go
```

**Terminal 2 (Node 2):**
```bash
cd example/basic/node2
go run main.go
```

**Terminal 3 (Node 3):**
```bash
cd example/basic/node3
go run main.go
```

**Terminal 4 (Node 4):**
```bash
cd example/basic/node4
go run main.go
```

### 2. CLI Commands

Each node provides an interactive CLI with the following commands:

| Command | Description | Example |
| :--- | :--- | :--- |
| `set <key> <val>` | Set a key-value pair. Requests are forwarded to Leader. | `set user:1 bob` |
| `get <key>` | Get a value by key (Linearizable Read). | `get user:1` |
| `del <key>` | Delete a key. | `del user:1` |
| `search <query> [limit] [offset]` | Search keys using SQL-like syntax. | `search key like "user:*" 10 0` |
| `demodata <count> <pattern>` | Generate demo data. Pattern supports `*` replacement. | `demodata 100 user.name.u*` |
| `stats` | Show current node status, term, and indices. | `stats` |
| `binlog` | Show the last CommitIndex in the Raft log. | `binlog` |
| `db` | Show the last CommitIndex applied to the DB. | `db` |
| `join <nodeID> <addr>` | (Leader Only) Add a new node to the cluster. | `join node3 127.0.0.1:9003` |
| `leave <nodeID>` | (Leader Only) Remove a node from the cluster. | `leave node3` |
| `help` | Show this help message. | `help` |

### 3. Test Workflow

1.  **Verify Initial Cluster**: Check `stats` on Node 1 and Node 2. One should be Leader, the other Follower.
2.  **Generate Data**: On Node 1 (or any node), run `demodata 100 user.*`.
3.  **Read Data**: Verify data availability on Node 2 using `get user.1` or `search key like "user.*"`.
4.  **Expand Cluster**:
    - Determine the Leader (e.g., Node 1).
    - On Leader, run: `join node3 127.0.0.1:9003`.
    - On Leader, run: `join node4 127.0.0.1:9004`.
5.  **Verify Replication**: Check if Node 3 and Node 4 have the data using `search` or `get`.
6.  **Delete Data**: Run `del user.1`. Verify it's gone on all nodes.
7.  **Inspect Logs**: Use `binlog` and `db` to see the commit indices matching across the cluster.