Crate autumn_plugin_clickhouse 

Autumn plugin for ClickHouse.

Add ClickHousePlugin to the app. Then use the ClickHouse extractor in a handler. ClickHouse is the OLAP/analytics counterpart to the DuckDB plugin: it queries a remote ClickHouse server over HTTP instead of an embedded database.

use autumn_plugin_clickhouse::{ClickHouse, ClickHousePlugin, ClickHouseResultExt as _};
use autumn_web::prelude::*;

#[derive(clickhouse::Row, serde::Serialize, serde::Deserialize)]
struct EventCount {
    name: String,
    count: u64,
}

#[get("/events/counts")]
async fn event_counts(db: ClickHouse) -> AutumnResult<Json<Vec<EventCount>>> {
    let rows = db
        .fetch_all::<EventCount>("SELECT name, count() AS count FROM events GROUP BY name")
        .await
        .or_http()?;
    Ok(Json(rows))
}

autumn_web::app()
    .plugin(ClickHousePlugin::new().configure(|c| {
        c.url = "http://localhost:8123".into();
        c.database = "analytics".into();
    }))
    .routes(routes![event_counts])
    .run()
    .await;

The plugin reads [clickhouse] in autumn.toml. See config for the keys.

What the plugin gives

• ClickHouse: typed SELECT queries with #[derive(clickhouse::Row)] structs, one-batch ClickHouse::insert and the batching Inserter, plus ClickHouse::execute for DDL.
• migrate: runs ordered CREATE TABLE IF NOT EXISTS migrations at startup.
• A HealthOnly readiness check that runs SELECT 1, and Prometheus call counters.

Limits

• Each call has the timeout_ms timeout. A timed-out call gives ClickHouseError::Timeout.
• Rows must be owned structs: #[derive(clickhouse::Row, serde::Serialize, serde::Deserialize)] without lifetimes.
• Logs, error text and Debug output do not have row data, server messages or passwords.
• The plugin needs a reachable ClickHouse server. The startup ping stops the boot if the server is down. Tests use the clickhouse mock server, not a live server.

Re-exports

pub use config::ClickHouseConfig;

pub use config::ConfigError;

pub use config::DEFAULT_SECTION;

pub use clickhouse;

Modules

config

The [clickhouse] section of autumn.toml.

Structs

ClickHouse

The ClickHouse handle for Autumn handlers.

ClickHousePlugin

Installs a ClickHouse handle in an Autumn app.

InsertStats

The statistics of an inserter commit.

Inserter

An insert batcher. It holds rows and commits them when a limit hits.

Metrics

Counters for all calls of one client.

Migration

One DDL statement with a name.

Enums

ClickHouseError

An error from the plugin.

ErrorKind

The kind of a ClickHouse error.

Constants

PLUGIN_NAME

The plugin name in Autumn diagnostics.

Traits

ClickHouseResultExt

Adds or_http to Result<T, ClickHouseError>.

Functions

migrate

Runs the migrations in order. It stops at the first failure.