Async ClickHouse Client

Asynchronous Yandex ClickHouse client library for rust programming language.

Installation

Library hosted on crates.io.

[dependencies]
clickhouse-rs = "*"

Supported data types

• Date
• DateTime
• Decimal(P, S)
• Float32, Float64
• String, FixedString(N)
• UInt8, UInt16, UInt32, UInt64, Int8, Int16, Int32, Int64
• Nullable(T)
• Array(UInt/Int/Float/String/Date/DateTime)
• IPv4/IPv6
• UUID

DNS

schema://user:password@host[:port]/database?param1=value1&...&paramN=valueN

parameters:

• compression - Whether or not use compression (defaults to none). Possible choices:

  • none
  • lz4

• readonly - Restricts permissions for read data, write data and change settings queries. (defaults to none). Possible choices:

  • 0 - All queries are allowed.
  • 1 - Only read data queries are allowed.
  • 2 - Read data and change settings queries are allowed.

• connection_timeout - Timeout for connection (defaults to 500 ms)

• query_timeout - Timeout for queries (defaults to 180 sec).

• insert_timeout - Timeout for inserts (defaults to 180 sec).

• execute_timeout - Timeout for execute (defaults to 180 sec).

• keepalive - TCP keep alive timeout in milliseconds.

• nodelay - Whether to enable TCP_NODELAY (defaults to true).

• pool_min - Lower bound of opened connections for Pool (defaults to 10).

• pool_max - Upper bound of opened connections for Pool (defaults to 20).

• ping_before_query - Ping server every time before execute any query. (defaults to true).

• send_retries - Count of retry to send request to server. (defaults to 3).

• retry_timeout - Amount of time to wait before next retry. (defaults to 5 sec).

• ping_timeout - Timeout for ping (defaults to 500 ms).

• alt_hosts - Comma separated list of single address host for load-balancing.

example:

tcp://user:password@host:9000/clicks?compression=lz4&ping_timeout=42ms

Optional features

clickhouse-rs puts some functionality behind optional features to optimize compile time for the most common use cases. The following features are available.

• tokio_io (enabled by default) — I/O based on Tokio.
• async_std — I/O based on async-std (doesn't work together with tokio_io).
• tls — TLS support (allowed only with tokio_io).

Example

use clickhouse_rs::{Block, Pool};
use std::error::Error;

#[tokio::main]
async fn main() -> Result<(), Box<dyn Error>> {
    let ddl = r"
        CREATE TABLE IF NOT EXISTS payment (
            customer_id  UInt32,
            amount       UInt32,
            account_name Nullable(FixedString(3))
        ) Engine=Memory";

    let block = Block::new()
        .column("customer_id",  vec![1_u32,  3,  5,  7,  9])
        .column("amount",       vec![2_u32,  4,  6,  8, 10])
        .column("account_name", vec![Some("foo"), None, None, None, Some("bar")]);

    let pool = Pool::new(database_url);

    let mut client = pool.get_handle().await?;
    client.execute(ddl).await?;
    client.insert("payment", block).await?;
    let block = client.query("SELECT * FROM payment").fetch_all().await?;

    for row in block.rows() {
        let id: u32             = row.get("customer_id")?;
        let amount: u32         = row.get("amount")?;
        let name: Option<&str>  = row.get("account_name")?;
        println!("Found payment {}: {} {:?}", id, amount, name);
    }

    Ok(())
}