cronoq-store-sqlite

A SQLite store for cronoq: durable scheduler state in one local file, with no database server.

• Write-ahead state: every engine state transition is committed before submitters are acknowledged, in one transaction per engine step. The WAL journal is synced on every commit by default.
• Leader and standbys: processes on the same host can share the file. One leads through a renewed lease; the others take over when the lease runs out, or at once when the leader shuts down cleanly.
• Fencing: every commit checks the fencing epoch inside its write transaction, so a paused old leader cannot write after a standby replaced it.
• Housekeeping: prune(older_than) removes old finished tasks; get_task looks tasks up by id or key.
• Files: created readable and writable by the owner only (on Unix). Keep the file on a local filesystem; for several hosts, use cronoq-store-postgres.

use bytes::Bytes;
use cronoq::{Pool, Scheduler};
use cronoq_store_sqlite::SqliteStore;

# async fn demo() -> Result<(), Box<dyn std::error::Error>> {
let store = SqliteStore::open("/var/lib/cronoq/state.db").await?;
let sched = Scheduler::<Bytes, Bytes>::builder()
    .pool(Pool::new("default").executor_fn(|_ctx, p: std::sync::Arc<Bytes>| async move {
        Ok::<_, cronoq::TaskError>((*p).clone())
    }))
    .store(store.clone())
    .build() // blocks until this process is the leader
    .await?;
# Ok(()) }

cronoq-server uses this store when configured with [store] kind = "sqlite".

• 📘 Durability and HA

Licensed under MIT or Apache-2.0, at your option.