jobs-actix: simplify manager, add _with_threads option, add metrics

jobs-actix/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "background-jobs-actix"
 description = "in-process jobs processor based on Actix"
-version = "0.13.1"
+version = "0.14.0"
 license = "AGPL-3.0"
 authors = ["asonix <asonix@asonix.dog>"]
 repository = "https://git.asonix.dog/asonix/background-jobs"
@@ -14,9 +14,10 @@ actix-rt = "2.5.1"
 anyhow = "1.0"
 async-mutex = "1.0.1"
 async-trait = "0.1.24"
-background-jobs-core = { version = "0.13.0", path = "../jobs-core", features = [
+background-jobs-core = { version = "0.14.0", path = "../jobs-core", features = [
   "with-actix",
 ] }
+metrics = "0.20.1"
 tracing = "0.1"
 tracing-futures = "0.2"
 serde = { version = "1.0", features = ["derive"] }

jobs-actix/src/lib.rs

@@ -116,22 +116,24 @@
 use actix_rt::{Arbiter, ArbiterHandle};
 use anyhow::Error;
 use background_jobs_core::{
-    memory_storage::Timer, new_job, new_scheduled_job, Job, ProcessorMap, Stats, Storage,
+    memory_storage::Timer, new_job, new_scheduled_job, Job, ProcessorMap, Storage,
 };
 use std::{
     collections::BTreeMap,
     marker::PhantomData,
+    num::NonZeroUsize,
     ops::Deref,
     sync::Arc,
     time::{Duration, SystemTime},
 };
+use tokio::sync::Notify;
 
 mod every;
 mod server;
 mod storage;
 mod worker;
 
-use self::{every::every, server::Server, worker::LocalWorkerStarter};
+use self::{every::every, server::Server};
 
 pub use background_jobs_core::ActixJob;
 
@@ -153,65 +155,61 @@ impl Timer for ActixTimer {
 
 /// Manager for worker threads
 ///
-/// Manager attempts to restart workers as their arbiters die
+/// Manager attempts to restart workers as their arbiters die. Dropping the manager kills the
+/// workers
 pub struct Manager {
     // the manager arbiter
-    arbiter_dropper: Option<ArbiterDropper>,
+    arbiter: Option<Arbiter>,
 
     // handle for queueing
     queue_handle: QueueHandle,
 }
 
-struct ArbiterDropper {
-    arbiter: Option<Arbiter>,
-}
-
 impl Manager {
     /// Create a new manager to keep jobs alive
     ///
     /// Manager works by startinng a new Arbiter to run jobs, and if that arbiter ever dies, it
     /// spins up another one and spawns the workers again
-    fn new<State>(worker_config: WorkerConfig<State, Managed>) -> Self
+    fn new<State>(worker_config: WorkerConfig<State, Managed>, thread_count: NonZeroUsize) -> Self
     where
         State: Clone,
     {
         let manager_arbiter = Arbiter::new();
-        let worker_arbiter = Arbiter::new();
-        let notifier = Arc::new(tokio::sync::Notify::new());
-
         let queue_handle = worker_config.queue_handle.clone();
 
-        let drop_notifier = DropNotifier::new(Arc::clone(&notifier));
+        for i in 0..thread_count.into() {
+            let worker_config = worker_config.clone();
+
             manager_arbiter.spawn(async move {
-            let mut drop_notifier = drop_notifier;
+                let mut worker_arbiter = Arbiter::new();
-            let mut arbiter_dropper = ArbiterDropper::from(worker_arbiter);
 
                 loop {
-                let notified = notifier.notified();
+                    let notifier = DropNotifier::default();
-                worker_config.start_managed(&arbiter_dropper.handle(), &drop_notifier);
+                    worker_config.start_managed(&worker_arbiter.handle(), &());
 
-                notified.await;
+                    let notified = notifier.notify.notified();
-                tracing::warn!("Recovering from dead worker arbiter");
+
-                // drop_notifier needs to live at least as long as notifier.notified().await
+                    let drop_notifier = notifier.clone();
-                // in order to ensure we get notified by ticker or a worker, and not ourselves
+                    worker_arbiter.spawn(async move {
+                        std::future::pending::<()>().await;
                         drop(drop_notifier);
-
-                // Assume arbiter is dead if we were notified
-                let online = arbiter_dropper.spawn(async {});
-                if online {
-                    panic!("Arbiter should be dead by now");
-                }
-
-                drop(arbiter_dropper);
-
-                arbiter_dropper = ArbiterDropper::default();
-
-                drop_notifier = DropNotifier::new(Arc::clone(&notifier));
-            }
                     });
 
+                    notified.await;
+
+                    metrics::counter!("background-jobs.worker-arbiter.restart", 1, "number" => i.to_string());
+                    tracing::warn!("Recovering from dead worker arbiter");
+
+                    worker_arbiter.stop();
+                    let _ = worker_arbiter.join();
+
+                    worker_arbiter = Arbiter::new();
+                }
+            });
+        }
+
         Manager {
-            arbiter_dropper: Some(ArbiterDropper::from(manager_arbiter)),
+            arbiter: Some(manager_arbiter),
             queue_handle,
         }
     }
@@ -233,61 +231,21 @@ impl Deref for Manager {
 impl Drop for Manager {
     fn drop(&mut self) {
         tracing::warn!("Dropping manager, tearing down workers");
-        self.arbiter_dropper.take();
+        if let Some(arbiter) = self.arbiter.take() {
-    }
-}
-
-impl Deref for ArbiterDropper {
-    type Target = Arbiter;
-
-    fn deref(&self) -> &Self::Target {
-        self.arbiter.as_ref().unwrap()
-    }
-}
-
-impl Drop for ArbiterDropper {
-    fn drop(&mut self) {
-        tracing::warn!("Stopping and joining arbiter");
-        let arbiter = self.arbiter.take().unwrap();
             arbiter.stop();
             let _ = arbiter.join();
         }
-}
-
-impl From<Arbiter> for ArbiterDropper {
-    fn from(arbiter: Arbiter) -> Self {
-        Self {
-            arbiter: Some(arbiter),
-        }
     }
 }
 
-impl Default for ArbiterDropper {
+#[derive(Clone, Default)]
-    fn default() -> Self {
-        ArbiterDropper {
-            arbiter: Some(Arbiter::new()),
-        }
-    }
-}
-
-#[derive(Clone)]
 struct DropNotifier {
-    inner: Arc<std::sync::Mutex<Option<Arc<tokio::sync::Notify>>>>,
+    notify: Arc<Notify>,
-}
-
-impl DropNotifier {
-    fn new(notify: Arc<tokio::sync::Notify>) -> Self {
-        DropNotifier {
-            inner: Arc::new(std::sync::Mutex::new(Some(notify))),
-        }
-    }
 }
 
 impl Drop for DropNotifier {
     fn drop(&mut self) {
-        if let Some(notifier) = self.inner.lock().unwrap().take() {
+        self.notify.notify_waiters();
-            notifier.notify_waiters();
-        }
     }
 }
 
@@ -306,8 +264,10 @@ where
 }
 
 /// Marker type for Unmanaged workers
+#[derive(Clone)]
 pub struct Unmanaged;
 /// Marker type for Managed workers
+#[derive(Clone)]
 pub struct Managed;
 
 /// Worker Configuration
@@ -352,9 +312,14 @@ where
         }
     }
 
-    /// Start the workers on a managed arbiter, and return the manager struct
+    /// Start the workers on a managed thread, returning the manager struct
     pub fn start(self) -> Manager {
-        Manager::new(self)
+        Self::start_with_threads(self, NonZeroUsize::try_from(1).expect("nonzero"))
+    }
+
+    /// Start the workers on the specified number of managed threads, returning the Manager struct
+    pub fn start_with_threads(self, thread_count: NonZeroUsize) -> Manager {
+        Manager::new(self, thread_count)
     }
 }
 
@@ -448,7 +413,7 @@ where
                 let extras_2 = extras.clone();
 
                 arbiter.spawn_fn(move || {
-                    drop(LocalWorkerStarter::new(
+                    actix_rt::spawn(worker::local_worker(
                         queue,
                         processors.cached(),
                         server,
@@ -506,9 +471,4 @@ impl QueueHandle {
     {
         actix_rt::spawn(every(self.clone(), duration, job));
     }
-
-    /// Return an overview of the processor's statistics
-    pub async fn get_stats(&self) -> Result<Stats, Error> {
-        self.inner.get_stats().await
-    }
 }

jobs-actix/src/server.rs

@@ -3,7 +3,7 @@ use crate::{
     worker::Worker,
 };
 use anyhow::Error;
-use background_jobs_core::{NewJobInfo, ReturnJobInfo, Stats, Storage};
+use background_jobs_core::{NewJobInfo, ReturnJobInfo, Storage};
 use std::sync::Arc;
 use tracing::{error, trace};
 
@@ -60,8 +60,4 @@ impl Server {
     pub(crate) async fn return_job(&self, job: ReturnJobInfo) -> Result<(), Error> {
         self.storage.return_job(job).await
     }
-
-    pub(crate) async fn get_stats(&self) -> Result<Stats, Error> {
-        self.storage.get_stats().await
-    }
 }

jobs-actix/src/storage.rs

@@ -1,5 +1,5 @@
 use anyhow::Error;
-use background_jobs_core::{JobInfo, NewJobInfo, ReturnJobInfo, Stats, Storage};
+use background_jobs_core::{JobInfo, NewJobInfo, ReturnJobInfo, Storage};
 use uuid::Uuid;
 
 #[async_trait::async_trait]
@@ -9,8 +9,6 @@ pub(crate) trait ActixStorage {
     async fn request_job(&self, queue: &str, runner_id: Uuid) -> Result<JobInfo, Error>;
 
     async fn return_job(&self, ret: ReturnJobInfo) -> Result<(), Error>;
-
-    async fn get_stats(&self) -> Result<Stats, Error>;
 }
 
 pub(crate) struct StorageWrapper<S>(pub(crate) S)
@@ -35,8 +33,4 @@ where
     async fn return_job(&self, ret: ReturnJobInfo) -> Result<(), Error> {
         Ok(self.0.return_job(ret).await?)
     }
-
-    async fn get_stats(&self) -> Result<Stats, Error> {
-        Ok(self.0.get_stats().await?)
-    }
 }

jobs-actix/src/worker.rs

@@ -3,7 +3,7 @@ use std::future::Future;
 use crate::Server;
 use background_jobs_core::{CachedProcessorMap, JobInfo};
 use tokio::sync::mpsc::{channel, Sender};
-use tracing::{error, info, warn, Span};
+use tracing::Span;
 use tracing_futures::Instrument;
 use uuid::Uuid;
 
@@ -42,7 +42,7 @@ impl Worker for LocalWorkerHandle {
     async fn process(&self, job: JobInfo) -> Result<(), JobInfo> {
         match self.tx.clone().send(job).await {
             Err(e) => {
-                error!("Unable to send job");
+                tracing::error!("Unable to send job");
                 Err(e.0)
             }
             _ => Ok(()),
@@ -58,31 +58,17 @@ impl Worker for LocalWorkerHandle {
     }
 }
 
-pub(crate) struct LocalWorkerStarter<State: Clone + 'static, Extras: 'static> {
+struct LocalWorkerStarter<State: Clone + 'static, Extras: 'static> {
     queue: String,
     processors: CachedProcessorMap<State>,
     server: Server,
     extras: Option<Extras>,
 }
 
-impl<State: Clone + 'static, Extras: 'static> LocalWorkerStarter<State, Extras> {
-    pub(super) fn new(
-        queue: String,
-        processors: CachedProcessorMap<State>,
-        server: Server,
-        extras: Extras,
-    ) -> Self {
-        LocalWorkerStarter {
-            queue,
-            processors,
-            server,
-            extras: Some(extras),
-        }
-    }
-}
-
 impl<State: Clone + 'static, Extras: 'static> Drop for LocalWorkerStarter<State, Extras> {
     fn drop(&mut self) {
+        metrics::gauge!("background-jobs.worker.running", -1.0, "queue" => self.queue.clone());
+
         let res = std::panic::catch_unwind(|| actix_rt::Arbiter::current().spawn(async move {}));
 
         let extras = self.extras.take().unwrap();
@@ -95,7 +81,7 @@ impl<State: Clone + 'static, Extras: 'static> Drop for LocalWorkerStarter<State,
                 extras,
             ));
         } else {
-            warn!("Not restarting worker, Arbiter is dead");
+            tracing::warn!("Not restarting worker, Arbiter is dead");
             drop(extras);
         }
     }
@@ -110,7 +96,7 @@ where
     F: Fn() -> Span,
 {
     fn drop(&mut self) {
-        (self.0)().in_scope(|| info!("Worker closing"));
+        (self.0)().in_scope(|| tracing::info!("Worker closing"));
     }
 }
 
@@ -127,21 +113,21 @@ async fn time_job<F: Future + Unpin>(mut future: F, job_id: Uuid) -> <F as Futur
 
                 if count > (60 * 60) {
                     if count % (60 * 20) == 0 {
-                        warn!("Job {} is taking a long time: {} hours", job_id, count / 60 / 60);
+                        tracing::warn!("Job {} is taking a long time: {} hours", job_id, count / 60 / 60);
                     }
                 } else if count > 60 {
                     if count % 20 == 0 {
-                        warn!("Job {} is taking a long time: {} minutes", job_id, count / 60);
+                        tracing::warn!("Job {} is taking a long time: {} minutes", job_id, count / 60);
                     }
                 } else {
-                    info!("Job {} is taking a long time: {} seconds", job_id, count);
+                    tracing::info!("Job {} is taking a long time: {} seconds", job_id, count);
                 }
             }
         }
     }
 }
 
-async fn local_worker<State, Extras>(
+pub(crate) async fn local_worker<State, Extras>(
     queue: String,
     processors: CachedProcessorMap<State>,
     server: Server,
@@ -150,6 +136,8 @@ async fn local_worker<State, Extras>(
     State: Clone + 'static,
     Extras: 'static,
 {
+    metrics::gauge!("background-jobs.worker.running", 1.0, "queue" => queue.clone());
+
     let starter = LocalWorkerStarter {
         queue: queue.clone(),
         processors: processors.clone(),
@@ -171,11 +159,13 @@ async fn local_worker<State, Extras>(
             .instrument(span.clone())
             .await
         {
+            metrics::counter!("background-jobs.worker.failed-request", 1);
+
             let display = format!("{}", e);
             let debug = format!("{:?}", e);
             span.record("exception.message", &tracing::field::display(&display));
             span.record("exception.details", &tracing::field::display(&debug));
-            span.in_scope(|| error!("Failed to notify server of ready worker, {}", e));
+            span.in_scope(|| tracing::error!("Failed to notify server of ready worker, {}", e));
             break;
         }
         drop(span);
@@ -188,11 +178,13 @@ async fn local_worker<State, Extras>(
 
             let span = handle.span("return");
             if let Err(e) = server.return_job(return_job).instrument(span.clone()).await {
+                metrics::counter!("background-jobs.worker.failed-return", 1);
+
                 let display = format!("{}", e);
                 let debug = format!("{:?}", e);
                 span.record("exception.message", &tracing::field::display(&display));
                 span.record("exception.details", &tracing::field::display(&debug));
-                span.in_scope(|| warn!("Failed to return completed job, {}", e));
+                span.in_scope(|| tracing::warn!("Failed to return completed job, {}", e));
             }
 
             continue;