Notice: Experimental, not intended for production use yet

A lightweight and embeddable durable execution runtime for Rust. Inspired by the Durable Task Framework and Temporal.

Latest Release: v0.1.6 — Large payload stress test, memory optimizations, stress test monitoring. See CHANGELOG.md for release notes.

What you can build with this

• Function chaining: model a multi-step process as sequential awaits where each step depends on prior results.
• Fan-out/fan-in: schedule many activities in parallel and deterministically aggregate results.
• Human interaction (external events): wait for out-of-band approvals, callbacks, or webhooks and then resume.
• Durable timers and deadlines: sleep for minutes/hours/days without holding threads; resume exactly-once after timeouts. Use ctx.schedule_timer() for orchestration-level delays. Activities can sleep/poll internally as part of their work (e.g., provisioning resources).
• Saga-style compensation: on failure, run compensating actions to roll back prior steps.
• Built-in activity retry: ctx.schedule_activity_with_retry() with configurable backoff (exponential, linear, fixed) and per-attempt timeouts.

These patterns are enabled by deterministic replay, correlation IDs, durable timers, and external event handling.

Getting started samples

• Start here: See docs/ORCHESTRATION-GUIDE.md for complete guide to writing workflows
• Quick start: Run cargo run --example hello_world to see Duroxide in action
• Advanced patterns: Check tests/e2e_samples.rs for comprehensive usage patterns
• Provider implementation: See docs/provider-implementation-guide.md for building custom providers
• Provider testing: See docs/provider-testing-guide.md for testing custom providers
• Observability: See docs/observability-guide.md for structured logging and metrics

What it is

• Deterministic orchestration core with correlated event IDs and replay safety
• Message-driven runtime built on Tokio, with two dispatchers:
  • OrchestrationDispatcher (orchestrator queue) - processes workflow turns and durable timers
  • WorkDispatcher (worker queue) - executes activities with automatic lock renewal
• Storage-agnostic via Provider trait (SQLite provider with in-memory and file-based modes)
• Configurable polling frequency, lock timeouts, and automatic lock renewal for long-running activities

How it works (brief)

• The orchestrator runs turn-by-turn. Each turn it is polled once, may schedule actions, then the runtime waits for completions.
• Every operation has a correlation id. Scheduling is recorded as history events (e.g., ActivityScheduled) and completions are matched by id (e.g., ActivityCompleted).
• The runtime appends new events and advances turns; work is routed through provider-backed queues (Orchestrator and Worker) using peek-lock semantics. Timers are handled via orchestrator queue with delayed visibility.
• Deterministic future aggregation: ctx.select2, ctx.select(Vec), and ctx.join(Vec) resolve by earliest completion index in history (not polling order).
• Logging is replay-safe via tracing and the ctx.trace_* helpers (implemented as a deterministic system activity). We do not persist trace events in history.
• Providers enforce a history cap (default 1024; tests use a smaller cap). If an append would exceed the cap, they return an error; the runtime fails the run to preserve determinism (no truncation).

Key types

• OrchestrationContext: schedules work (schedule_activity, schedule_timer, schedule_wait, schedule_sub_orchestration, schedule_orchestration) and exposes deterministic select2/select/join, trace_*, continue_as_new.
• DurableFuture: returned by schedule_*; use into_activity(), into_timer(), into_event(), into_sub_orchestration() (and _typed variants) to await.
• Event/Action: immutable history entries and host-side actions, including ContinueAsNew.
• Provider: persistence + queues abstraction with atomic operations and lock renewal (SqliteProvider with in-memory and file-based modes).
• RuntimeOptions: configure concurrency, lock timeouts, and lock renewal buffer for long-running activities.
• OrchestrationRegistry / ActivityRegistry: register orchestrations/activities in-memory.

Project layout

• src/lib.rs — orchestration primitives and single-turn executor
• src/runtime/ — runtime, registries, workers, and polling engine
• src/providers/ — SQLite history store with transactional support
• tests/ — unit and e2e tests (see e2e_samples.rs to learn by example)

Install (when published)

[dependencies]
duroxide = { version = "0.1", features = ["sqlite"] }  # With bundled SQLite provider
# OR
duroxide = "0.1"  # Core only, bring your own Provider implementation

Hello world (activities + runtime)

Note: This example uses the bundled SQLite provider. Enable the sqlite feature in your Cargo.toml.

use std::sync::Arc;
use duroxide::{ActivityContext, Client, ClientError, OrchestrationContext, OrchestrationRegistry, OrchestrationStatus};
use duroxide::runtime::{self};
use duroxide::runtime::registry::ActivityRegistry;
use duroxide::providers::sqlite::SqliteProvider;

# #[tokio::main]
# async fn main() -> Result<(), Box<dyn std::error::Error>> {
let store = std::sync::Arc::new(SqliteProvider::new("sqlite:./data.db", None).await?);
let activities = ActivityRegistry::builder()
    .register("Hello", |ctx: ActivityContext, name: String| async move { Ok(format!("Hello, {name}!")) })
    .build();
let orch = |ctx: OrchestrationContext, name: String| async move {
    ctx.trace_info("hello started");
    let res = ctx.schedule_activity("Hello", name).into_activity().await.unwrap();
    Ok::<_, String>(res)
};
let orchestrations = OrchestrationRegistry::builder().register("HelloWorld", orch).build();
let rt = runtime::Runtime::start_with_store(store.clone(), Arc::new(activities), orchestrations).await;
let client = Client::new(store);
client.start_orchestration("inst-hello-1", "HelloWorld", "Rust").await?; // Returns Result<(), ClientError>
match client.wait_for_orchestration("inst-hello-1", std::time::Duration::from_secs(5)).await? {
    OrchestrationStatus::Completed { output } => assert_eq!(output, "Hello, Rust!"),
    OrchestrationStatus::Failed { details } => panic!("Failed: {}", details.display_message()),
    _ => panic!("Unexpected status"),
}
rt.shutdown(None).await;  // Graceful shutdown with 1s timeout
# Ok(())
# }

Parallel fan-out

async fn fanout(ctx: OrchestrationContext) -> Vec<String> {
    let f1 = ctx.schedule_activity("Greetings", "Gabbar");
    let f2 = ctx.schedule_activity("Greetings", "Samba");
    let outs = ctx.join(vec![f1, f2]).await; // history-ordered join
    outs
        .into_iter()
        .map(|o| match o {
            duroxide::DurableOutput::Activity(Ok(s)) => s,
            other => panic!("unexpected: {:?}", other),
        })
        .collect()
}

Control flow + timers + externals

use duroxide::DurableOutput;
async fn control(ctx: OrchestrationContext) -> String {
    let a = ctx.schedule_timer(std::time::Duration::from_millis(10));
    let b = ctx.schedule_wait("Evt");
    let (_idx, out) = ctx.select2(a, b).await;
    match out {
        DurableOutput::External(data) => data,
        DurableOutput::Timer => {
            // timer won; fall back to waiting for the event deterministically
            ctx.schedule_wait("Evt").into_event().await
        }
        other => panic!("unexpected: {:?}", other),
    }
}

Error handling (Result<String, String>)

async fn comp_sample(ctx: OrchestrationContext) -> String {
    match ctx.schedule_activity("Fragile", "bad").into_activity().await {
        Ok(v) => v,
        Err(e) => {
            ctx.trace_warn(format!("fragile failed error={e}"));
            ctx.schedule_activity("Recover", "").into_activity().await.unwrap()
        }
    }
}

ContinueAsNew and multi-execution

• Use ctx.continue_as_new(new_input) to end the current execution and immediately start a fresh execution with the provided input.
• Providers keep all executions' histories in the SQLite database with full ACID transactional support.
• The initial start_orchestration handle resolves with an empty success when ContinueAsNew occurs; the latest execution can be observed via status APIs.

Status and control-plane

• Client::get_orchestration_status(instance) -> Result<OrchestrationStatus, ClientError> where OrchestrationStatus is Running | Completed { output } | Failed { details: ErrorDetails } | NotFound
• Client::wait_for_orchestration(instance, timeout) -> Wait for completion with timeout, returns Result<OrchestrationStatus, ClientError>
• SQLite provider exposes execution-aware methods (list_executions, read_with_execution, etc.) for diagnostics.

Error classification

• Infrastructure errors: Provider failures, data corruption (retryable by runtime, abort turn)
• Configuration errors: Unregistered orchestrations/activities, nondeterminism (require deployment fix, abort turn)
• Application errors: Business logic failures (handled by orchestration code, propagate normally)
• Use ErrorDetails::category() for metrics, is_retryable() for retry logic, display_message() for logging

Local development

• Build: cargo build
• Test everything: cargo test --all -- --nocapture
• Run a specific test: cargo test --test e2e_samples sample_dtf_legacy_gabbar_greetings -- --nocapture

Stress testing

• Run all stress tests: ./run-stress-tests.sh (parallel orchestrations + large payload)
• Run specific test: ./run-stress-tests.sh --parallel-only or ./run-stress-tests.sh --large-payload
• Custom duration: ./run-stress-tests.sh 60 (runs for 60 seconds)
• Resource monitoring: Peak RSS and CPU usage tracked automatically (see STRESS_TEST_MONITORING.md)
• Result tracking: ./run-stress-tests.sh --track (saves to stress-test-results.md)
• See docs/provider-testing-guide.md for comprehensive stress testing guide

Runtime Configuration

• Configure lock timeouts, concurrency, and polling via RuntimeOptions
• Worker lock renewal automatically enabled for long-running activities (no configuration needed)
• Example: RuntimeOptions { worker_lock_timeout: Duration::from_secs(300), worker_lock_renewal_buffer: Duration::from_secs(30), ... }
• Lock renewal happens at (timeout - buffer) for timeouts ≥15s, or 0.5 * timeout for shorter timeouts
• See API docs for RuntimeOptions for complete configuration options

Observability

• Enable structured logging: RuntimeOptions { observability: ObservabilityConfig { log_format: LogFormat::Compact, ... }, ... }
• Default logs show only orchestration/activity traces at configured level; runtime internals at warn+
• Override with RUST_LOG for additional targets (e.g., RUST_LOG=duroxide::runtime=debug)
• All logs include instance_id, execution_id, orchestration_name, activity_name for correlation
• Optional OpenTelemetry metrics via observability feature flag
• Run cargo run --example with_observability to see structured logging in action
• Run cargo run --example metrics_cli to see observability dashboard
• See docs/observability-guide.md for complete guide

Notes

• Import as duroxide in Rust source.
• Timers are real time (Tokio sleep). External events are via Runtime::raise_event.
• Unknown-instance messages are logged and dropped. Providers persist history only (queues are in-memory runtime components).
• Logging is replay-safe by treating it as a system activity via ctx.trace_* helpers; logs are emitted through tracing at completion time (not persisted as history events).