Use cron-like scheduling in an async tokio environment. Also schedule tasks at an instant or repeat them at a fixed duration. Task's data can optionally be persisted using PostgreSQL or Nats.
Inspired by https://github.com/lholden/job_scheduler
Please see the Documentation for more details.
Be sure to add the job_scheduler crate to your Cargo.toml:
[dependencies]
tokio-cron-scheduler = "*"Creating a schedule for a job is done using the FromStr impl for the
Schedule type of the cron library.
The scheduling format is as follows:
sec min hour day of month month day of week year
* * * * * * *
Time is specified for UTC and not your local timezone. Note that the year may
be omitted. If you want for your timezone, append _tz to the job creation calls (for instance
Job::new_async vs Job::new_async_tz).
Comma separated values such as 5,8,10 represent more than one time value. So
for example, a schedule of 0 2,14,26 * * * * would execute on the 2nd, 14th,
and 26th minute of every hour.
Ranges can be specified with a dash. A schedule of 0 0 * 5-10 * * would
execute once per hour but only on day 5 through 10 of the month.
Day of the week can be specified as an abbreviation or the full name. A
schedule of 0 0 6 * * Sun,Sat would execute at 6am on Sunday and Saturday.
Per job you can be notified when the jobs were started, stopped and removed. Because these notifications are scheduled using tokio::spawn, the order of these are not guaranteed if the task finishes quickly.
A simple usage example:
use std::time::Duration;
use tokio_cron_scheduler::{Job, JobScheduler, JobSchedulerError};
#[tokio::main]
async fn main() -> Result<(), JobSchedulerError> {
let mut sched = JobScheduler::new().await?;
// Add basic cron job
sched.add(
Job::new("1/10 * * * * *", |_uuid, _l| {
println!("I run every 10 seconds");
})?
).await?;
// Add async job
sched.add(
Job::new_async("1/7 * * * * *", |uuid, mut l| {
Box::pin(async move {
println!("I run async every 7 seconds");
// Query the next execution time for this job
let next_tick = l.next_tick_for_job(uuid).await;
match next_tick {
Ok(Some(ts)) => println!("Next time for 7s job is {:?}", ts),
_ => println!("Could not get next tick for 7s job"),
}
})
})?
).await?;
// Add one-shot job with given duration
sched.add(
Job::new_one_shot(Duration::from_secs(18), |_uuid, _l| {
println!("I only run once");
})?
).await?;
// Create repeated job with given duration, make it mutable to edit it afterwards
let mut jj = Job::new_repeated(Duration::from_secs(8), |_uuid, _l| {
println!("I run repeatedly every 8 seconds");
})?;
// Add actions to be executed when the jobs starts/stop etc.
jj.on_start_notification_add(&sched, Box::new(|job_id, notification_id, type_of_notification| {
Box::pin(async move {
println!("Job {:?} was started, notification {:?} ran ({:?})", job_id, notification_id, type_of_notification);
})
})).await?;
jj.on_stop_notification_add(&sched, Box::new(|job_id, notification_id, type_of_notification| {
Box::pin(async move {
println!("Job {:?} was completed, notification {:?} ran ({:?})", job_id, notification_id, type_of_notification);
})
})).await?;
jj.on_removed_notification_add(&sched, Box::new(|job_id, notification_id, type_of_notification| {
Box::pin(async move {
println!("Job {:?} was removed, notification {:?} ran ({:?})", job_id, notification_id, type_of_notification);
})
})).await?;
sched.add(jj).await?;
// Feature 'signal' must be enabled
sched.shutdown_on_ctrl_c();
// Add code to be run during/after shutdown
sched.set_shutdown_handler(Box::new(|| {
Box::pin(async move {
println!("Shut down done");
})
}));
// Start the scheduler
sched.start().await?;
// Wait while the jobs run
tokio::time::sleep(Duration::from_secs(100)).await;
Ok(())
}You can create a job using a specific timezone using the JobBuilder API.
chrono-tz is not included into the dependencies, so you need to add it to your Cargo.toml if you
would like to have easy creation of a Timezone struct.
let job = JobBuilder::new()
.with_timezone(chrono_tz::Africa::Johannesburg)
.with_cron_job_type()
.with_schedule("*/2 * * * * *")
.unwrap()
.with_run_async(Box::new(|uuid, mut l| {
Box::pin(async move {
info!("JHB run async every 2 seconds id {:?}", uuid);
let next_tick = l.next_tick_for_job(uuid).await;
match next_tick {
Ok(Some(ts)) => info!("Next time for JHB 2s is {:?}", ts),
_ => warn!("Could not get next tick for 2s job"),
}
})
}))
.build()
.unwrap();- job_scheduler The crate that inspired this one
- cron the cron expression parser we use.
- schedule-rs is a similar rust library that implements it's own cron expression parser.
TokioCronScheduler is licensed under either of
- Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
- MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)
The MetadataStore and NotificationStore traits can be implemented and be used in the JobScheduler.
A default volatile hashmap based version is provided with the SimpleMetadataStore and SimpleNotificationStore. A persistent version using Nats is provided with NatsMetadataStore and NatsNotificationStore.
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.
Please see the CONTRIBUTING file for more information.
Since 0.7
Enables Prost-generated data structures to be used by stores that need to get the bytes of the data structs. The Nats and Postgres stores depend on this feature being enabled.
Since 0.6
Adds the Postgres metadata store, notification store (PostgresMetadataStore, PostgresNotificationStore). Use a Postgres database to store the metadata and notifications data.
See PostgreSQL docs
Since 0.6
Uses postgres-native-tls crate as the TLS provider for the PostgreSQL connection.
Since 0.6
Uses the postgres-openssl crate as the TLS provider for the PostgreSQL connection.
Since 0.6
Adds the Nats metadata store, notification store (NatsMetadataStore, NatsNotificationStore). Use a Nats system as a way to store the metadata and notifications.
See Nats docs
Since 0.5
Adds shutdown_on_signal and shutdown_on_ctrl_c to the scheduler.
Both shuts the system down (stops the scheduler, removes all the tasks) when a signal
was received.
When doing a tokio::test, remember to have it run in a multi-threaded context otherwise the test
will hang on scheduler.add().
For example:
#[cfg(test)]
mod test {
use tokio_cron_scheduler::{Job, JobScheduler};
use tracing::{info, Level};
use tracing_subscriber::FmtSubscriber;
// Needs multi_thread to test, otherwise it hangs on scheduler.add()
#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
// #[tokio::test]
async fn test_schedule() {
let subscriber = FmtSubscriber::builder()
.with_max_level(Level::TRACE)
.finish();
tracing::subscriber::set_global_default(subscriber)
.expect("Setting default subscriber failed");
info!("Create scheduler");
let scheduler = JobScheduler::new().await.unwrap();
info!("Add job");
scheduler
.add(
Job::new_async("*/1 * * * * *", |_, _| {
Box::pin(async {
info!("Run every seconds");
})
})
.unwrap(),
)
.await
.expect("Should be able to add a job");
scheduler.start().await.unwrap();
tokio::time::sleep(core::time::Duration::from_secs(20)).await;
}
}Runs the in-memory hashmap based storage
cargo run --example simple --features="tracing-subscriber"Needs a running PostgreSQL instance first:
docker run --rm -it -p 5432:5432 -e POSTGRES_USER="postgres" -e POSTGRES_PASSWORD="" -e POSTGRES_HOST_AUTH_METHOD="trust" postgres:14.1Then run the example:
POSTGRES_INIT_METADATA=true POSTGRES_INIT_NOTIFICATIONS=true cargo run --example postgres --features="postgres_storage tracing-subscriber"Needs a running Nats instance first with Jetstream enabled:
docker run --rm -it -p 4222:4222 -p 6222:6222 -p 7222:7222 -p 8222:8222 nats -js -DVThen run the example:
cargo run --example nats --features="nats_storage tracing-subscriber"
