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# Rust Native API

Apache IoTDB provides an official Rust client SDK: [apache/iotdb-client-rust](https://github.com/apache/iotdb-client-rust). It speaks the Thrift RPC protocol (default port 6667) and supports both IoTDB data models:

- **Tree model** — `Session` / `SessionPool`: device/timeseries paths (`root.sg.d1.s1`), covered in this document
- **Table model** — `TableSession` / `TableSessionPool`: relational SQL dialect

## 1. Requirements

- Rust 1.75+
- Apache IoTDB 2.x — see [COMPATIBILITY.md](https://github.com/apache/iotdb-client-rust/blob/main/COMPATIBILITY.md) for the full server version matrix

## 2. Installation

Once published to crates.io:

```toml
[dependencies]
iotdb-client-rust = "0.1"
```

Until then, use a git dependency:

```toml
[dependencies]
iotdb-client = { git = "https://github.com/apache/iotdb-client-rust" }
```

The import name is `iotdb_client` in both cases.

## 3. Quick start

```rust
use iotdb_client::{Result, Session, SessionConfig, TSDataType, Tablet, Value};

fn main() -> Result<()> {
    let config = SessionConfig::default().with_node_urls(&["127.0.0.1:6667"])?;
    let mut session = Session::new(config);
    session.open()?;

    session.execute_non_query("CREATE DATABASE root.demo")?;
    session.execute_non_query(
        "CREATE TIMESERIES root.demo.d1.temperature WITH DATATYPE=DOUBLE, ENCODING=PLAIN",
    )?;

    // Batch write via a column-major tablet (nulls allowed).
    let mut tablet = Tablet::new(
        "root.demo.d1",
        vec!["temperature".into()],
        vec![TSDataType::Double],
    )?;
    tablet.add_row(1_720_000_000_000, vec![Some(Value::Double(21.5))])?;
    tablet.add_row(1_720_000_001_000, vec![None])?; // null cell
    session.insert_tablet(&tablet)?;

    // Or write a single row via insertRecord (aligned variants and
    // multi-row insert_records / insert_records_of_one_device also exist).
    session.insert_record(
        "root.demo.d1",
        1_720_000_002_000,
        vec!["temperature".into()],
        &[Value::Double(22.0)],
        false, // is_aligned
    )?;

    // Query with row iteration; the dataset borrows the session until dropped.
    {
        let mut dataset = session.execute_query("SELECT temperature FROM root.demo.d1")?;
        while let Some(row) = dataset.next_row()? {
            println!("ts={:?} values={:?}", row.timestamp, row.values);
        }
    }

    session.execute_non_query("DELETE DATABASE root.demo")?;
    session.close()
}
```

## 4. Session pool

`SessionPool` is a thread-safe pool for concurrent workloads. `acquire()` returns an RAII guard that releases the session back to the pool on drop:

```rust
use std::sync::Arc;
use iotdb_client::{Result, SessionPool, SessionPoolConfig};

fn main() -> Result<()> {
    let config = SessionPoolConfig {
        max_size: 4,
        ..SessionPoolConfig::default()
    }
    .with_node_urls(&["127.0.0.1:6667"])?;
    let pool = Arc::new(SessionPool::new(config)?);

    let handles: Vec<_> = (0..4)
        .map(|_| {
            let pool = Arc::clone(&pool);
            std::thread::spawn(move || -> Result<()> {
                let mut session = pool.acquire()?;
                session.execute_non_query("SHOW DATABASES")?;
                Ok(())
            })
        })
        .collect();
    for handle in handles {
        handle.join().expect("thread panicked")?;
    }

    pool.close();
    Ok(())
}
```

## 5. TLS & RPC compression

**RPC compression** (the Thrift compact protocol) must match the server setting `dn_rpc_thrift_compression_enable` (default `false`):

```rust
let config = SessionConfig { enable_rpc_compression: true, ..Default::default() };
```

**TLS** is behind the `tls` cargo feature:

```toml
iotdb-client-rust = { version = "0.1", features = ["tls"] }
```

```rust
let config = SessionConfig {
    use_ssl: true,
    ca_cert_path: Some("ca.pem".into()),  // trust a private CA / self-signed cert
    accept_invalid_certs: false,          // true skips verification (tests only!)
    domain_override: None,                // SNI/validation hostname when connecting by IP
    ..Default::default()
};
```

## 6. Examples

Full runnable examples live in the repository's [`examples/`](https://github.com/apache/iotdb-client-rust/tree/main/examples) directory:

```sh
cargo run --example tree_session
cargo run --example table_session
cargo run --example session_pool
```