diff --git a/docs/swarm/review-classifier.md b/docs/swarm/review-classifier.md index a3184d95..ff3bc8bc 100644 --- a/docs/swarm/review-classifier.md +++ b/docs/swarm/review-classifier.md @@ -84,6 +84,16 @@ as a reviewer on a PR starts a run: 4. The controller posts the result on the PR as the service account's review, on the commit it read. +When a post can't reach the secret store or the forge, because the +connection fails or a try gets no answer within two minutes, the controller +tries it up to six times over about five minutes, enough to outlast a +swarm-bao restart, with the same verdict. It doesn't retry any other failure, +such as the forge refusing the review. A post that still fails ends the run +as `post-failed`, and nothing appears on the PR. The account's review +request is still pending then, and the forge sends no event for a request +that's already standing: remove the service account's review request, then +request it again to start a fresh run. + A verdict belongs to the commit it ran on. A push starts no run. Once the PR's head moves, requesting the service account as a reviewer again starts a fresh run on the new head. diff --git a/swarm-controller/src/review_classifier/review.rs b/swarm-controller/src/review_classifier/review.rs index b49a4680..f84e6ef5 100644 --- a/swarm-controller/src/review_classifier/review.rs +++ b/swarm-controller/src/review_classifier/review.rs @@ -17,7 +17,9 @@ use std::collections::HashSet; use std::fmt::Write as _; use std::future::Future; use std::sync::{Arc, Mutex, MutexGuard, PoisonError}; +use std::time::Duration; +use forgejo_api::ForgejoError; use serde::Deserialize; use swarm_queue_client::review_classifier::{Overall, Reply, Row, TryOut, Verdict}; use tokio::sync::Notify; @@ -33,6 +35,18 @@ use crate::forge::{self, classifier_account::LOGIN, classifier_account::Review}; /// The most review runs waiting for a slot. const MAX_WAITING_REVIEWS: usize = 8; +/// The waits before each retry of a post that failed with a [`transient`] +/// error or got no answer: six tries spread over about five minutes, sized to +/// outlast a swarm-bao restart (about 3-4 minutes observed on 2026-10-14). +/// Each try has its own [`forge::FORGE_DEADLINE`]. +const POST_RETRY_WAITS: [Duration; 5] = [ + Duration::from_secs(5), + Duration::from_secs(15), + Duration::from_secs(45), + Duration::from_secs(90), + Duration::from_secs(150), +]; + /// The forge's review events. #[derive(Debug, Clone, Copy, PartialEq, Eq)] enum Event { @@ -468,15 +482,12 @@ async fn post( ) -> Result, String> { let repo = format!("{}/{}", req.owner, req.name); let event = review.event; - let sent = forge::within_forge_deadline( - "review classifier review", - poster.post(&req.owner, &req.name, req.pr, head, review), - ) - .await; + let mut tries = 0; + let sent = post_retrying(poster, req, head, &review, &mut tries).await; match sent { Some(Ok(url)) => { tracing::info!( - %repo, pr = req.pr, head_sha = head.unwrap_or_default(), event, + %repo, pr = req.pr, head_sha = head.unwrap_or_default(), event, tries, "review classifier review posted" ); Ok(url) @@ -484,15 +495,74 @@ async fn post( Some(Err(e)) => { let error = format!("{e:#}"); tracing::warn!( - %repo, pr = req.pr, %error, + %repo, pr = req.pr, %error, tries, "posting the review classifier's review failed" ); Err(format!("posting the review failed: {error}")) } - None => Err("the forge did not answer the review's post within the deadline".to_owned()), + None => { + tracing::warn!( + %repo, pr = req.pr, tries, + "posting the review classifier's review failed: no answer within the deadline" + ); + Err("the forge did not answer the review's post within the deadline".to_owned()) + } } } +/// Post `review`, each try within [`forge::FORGE_DEADLINE`], and post it +/// again after each of [`POST_RETRY_WAITS`] while a try fails with a +/// [`transient`] error or gets no answer by the deadline. The last try's +/// result, `None` when it got no answer; `tries` counts the tries made. +async fn post_retrying( + poster: &impl ReviewPoster, + req: &Requested, + head: Option<&str>, + review: &Review, + tries: &mut usize, +) -> Option>> { + let mut waits = POST_RETRY_WAITS.iter(); + loop { + *tries += 1; + let sent = forge::within_forge_deadline( + "review classifier review", + poster.post(&req.owner, &req.name, req.pr, head, review.clone()), + ) + .await; + let error = match &sent { + Some(Err(e)) if transient(e) => format!("{e:#}"), + None => "no answer within the deadline".to_owned(), + Some(_) => return sent, + }; + let Some(wait) = waits.next() else { + return sent; + }; + tracing::info!( + repo = %format!("{}/{}", req.owner, req.name), pr = req.pr, + %error, tries, wait_s = wait.as_secs(), + "posting the review classifier's review failed; trying again" + ); + tokio::time::sleep(*wait).await; + } +} + +/// Whether a post that failed with `e` may succeed when tried again: the +/// connection to the secret store or the forge failed or timed out. An answer +/// from either, such as a 4xx, is not transient. +/// +/// The store's client puts its `reqwest::Error` in the chain itself; the +/// forge's wraps it in a transparent [`ForgejoError::ReqwestError`], whose +/// chain skips it. +fn transient(e: &anyhow::Error) -> bool { + e.chain().any(|cause| { + let http = match cause.downcast_ref::() { + Some(ForgejoError::ReqwestError(e)) => Some(e), + _ => cause.downcast_ref::(), + }; + http.is_some_and(|e| e.is_connect() || e.is_timeout()) + }) +} + /// How a run ended, as its record holds it. struct Ended { outcome: RunOutcome, @@ -798,6 +868,7 @@ mod tests { use std::sync::atomic::{AtomicUsize, Ordering}; use std::time::Duration; + use axum::http::StatusCode; use swarm_queue_client::review_classifier::Polarity; use super::*; @@ -1378,6 +1449,239 @@ mod tests { ); } + /// The forge client's error for a port nothing listens on. + async fn refused_by_port() -> ForgejoError { + let listener = tokio::net::TcpListener::bind("127.0.0.1:0").await.unwrap(); + let url = url::Url::parse(&format!("http://{}/", listener.local_addr().unwrap())).unwrap(); + drop(listener); + let forge = forgejo_api::Forgejo::new(forgejo_api::Auth::Token("stub-token"), url).unwrap(); + forge.user_get_current().await.expect_err("nothing listens") + } + + /// A refused connection as the forge client reports it. + async fn forge_refused() -> anyhow::Error { + anyhow::Error::from(refused_by_port().await).context("posting the review") + } + + /// A refused connection as the store client reports it: the + /// `reqwest::Error` itself in the chain, under the login's context. + async fn store_refused() -> anyhow::Error { + let ForgejoError::ReqwestError(e) = refused_by_port().await else { + panic!("a connect error is a reqwest error"); + }; + anyhow::Error::new(e) + .context("An error occurred with the request") + .context("logging in to the swarm secret store") + } + + /// A poster that fails with each of `failures` in turn, then posts. + struct Flaky { + failures: Mutex>, + tries: AtomicUsize, + posted: Posted, + } + + impl Flaky { + fn new(mut failures: Vec) -> Self { + failures.reverse(); + Self { + failures: Mutex::new(failures), + tries: AtomicUsize::new(0), + posted: Posted::default(), + } + } + } + + impl ReviewPoster for Flaky { + async fn post( + &self, + owner: &str, + repo: &str, + number: i64, + commit: Option<&str>, + review: Review, + ) -> anyhow::Result> { + self.tries.fetch_add(1, Ordering::SeqCst); + let failure = self.failures.lock().expect("unpoisoned").pop(); + match failure { + Some(e) => Err(e), + None => self.posted.post(owner, repo, number, commit, review).await, + } + } + } + + #[tokio::test] + async fn a_post_refused_a_connection_is_tried_again() { + let failures = vec![forge_refused().await, store_refused().await]; + tokio::time::pause(); + let approve = Reply::Done { + rows: vec![row(None, true, true)], + overall: Overall::Approve, + }; + let fake = Fake::new(approve, vec![rules_json()]); + let poster = Flaky::new(failures); + let started = tokio::time::Instant::now(); + let run = run(&fake, &fake, &fake, &poster, &request("r")).await; + assert_eq!(run.outcome, RunOutcome::Approved, "{:?}", run.detail); + assert_eq!(poster.tries.load(Ordering::SeqCst), 3); + assert_eq!(poster.posted.0.lock().expect("unpoisoned").len(), 1); + assert_eq!(fake.sent.lock().expect("unpoisoned").len(), 1, "one run"); + let waited = started.elapsed(); + assert!( + waited >= POST_RETRY_WAITS[0] + POST_RETRY_WAITS[1] && waited < POST_RETRY_WAITS[2], + "{waited:?}" + ); + } + + /// A secret store that refuses every connection until `up`. + struct Outage { + up: tokio::time::Instant, + refusals: Mutex>, + tries: AtomicUsize, + posted: Posted, + } + + impl ReviewPoster for Outage { + async fn post( + &self, + owner: &str, + repo: &str, + number: i64, + commit: Option<&str>, + review: Review, + ) -> anyhow::Result> { + self.tries.fetch_add(1, Ordering::SeqCst); + if tokio::time::Instant::now() < self.up { + return Err(self + .refusals + .lock() + .expect("unpoisoned") + .pop() + .expect("a refusal per try")); + } + self.posted.post(owner, repo, number, commit, review).await + } + } + + #[tokio::test] + async fn a_post_outlasts_a_secret_store_restart() { + let mut refusals = Vec::new(); + for _ in 0..=POST_RETRY_WAITS.len() { + refusals.push(store_refused().await); + } + tokio::time::pause(); + let approve = Reply::Done { + rows: vec![row(None, true, true)], + overall: Overall::Approve, + }; + let fake = Fake::new(approve, vec![rules_json()]); + let started = tokio::time::Instant::now(); + // swarm-bao was down 3m19s on 2026-10-14. + let down = Duration::from_secs(200); + let poster = Outage { + up: started + down, + refusals: Mutex::new(refusals), + tries: AtomicUsize::new(0), + posted: Posted::default(), + }; + let run = run(&fake, &fake, &fake, &poster, &request("r")).await; + assert_eq!(run.outcome, RunOutcome::Approved, "{:?}", run.detail); + assert_eq!(poster.posted.0.lock().expect("unpoisoned").len(), 1); + assert_eq!(fake.sent.lock().expect("unpoisoned").len(), 1, "one run"); + assert!(poster.tries.load(Ordering::SeqCst) > 1); + assert!(started.elapsed() >= down, "{:?}", started.elapsed()); + } + + /// A forge whose first post never answers. + #[derive(Default)] + struct HangsOnce { + tries: AtomicUsize, + posted: Posted, + } + + impl ReviewPoster for HangsOnce { + async fn post( + &self, + owner: &str, + repo: &str, + number: i64, + commit: Option<&str>, + review: Review, + ) -> anyhow::Result> { + if self.tries.fetch_add(1, Ordering::SeqCst) == 0 { + std::future::pending::<()>().await; + } + self.posted.post(owner, repo, number, commit, review).await + } + } + + #[tokio::test(start_paused = true)] + async fn a_post_with_no_answer_is_abandoned_at_its_deadline_and_tried_again() { + let approve = Reply::Done { + rows: vec![row(None, true, true)], + overall: Overall::Approve, + }; + let fake = Fake::new(approve, vec![rules_json()]); + let poster = HangsOnce::default(); + let started = tokio::time::Instant::now(); + let run = tokio::time::timeout( + Duration::from_hours(1), + run(&fake, &fake, &fake, &poster, &request("r")), + ) + .await + .expect("the hung try is abandoned"); + assert_eq!(run.outcome, RunOutcome::Approved, "{:?}", run.detail); + assert_eq!(poster.tries.load(Ordering::SeqCst), 2); + assert_eq!(poster.posted.0.lock().expect("unpoisoned").len(), 1); + assert!(started.elapsed() >= forge::FORGE_DEADLINE + POST_RETRY_WAITS[0]); + } + + #[tokio::test(start_paused = true)] + async fn a_post_the_forge_refused_is_not_tried_again() { + let approve = Reply::Done { + rows: vec![row(None, true, true)], + overall: Overall::Approve, + }; + let fake = Fake::new(approve, vec![rules_json()]); + let poster = Flaky::new(vec![ + ForgejoError::UnexpectedStatusCode(StatusCode::FORBIDDEN).into(), + ]); + let started = tokio::time::Instant::now(); + let run = run(&fake, &fake, &fake, &poster, &request("r")).await; + assert_eq!(run.outcome, RunOutcome::PostFailed); + assert_eq!(poster.tries.load(Ordering::SeqCst), 1); + assert!(poster.posted.0.lock().expect("unpoisoned").is_empty()); + assert_eq!(started.elapsed(), Duration::ZERO); + } + + #[tokio::test] + async fn a_post_refused_every_try_is_post_failed() { + let mut failures = Vec::new(); + for _ in 0..=POST_RETRY_WAITS.len() { + failures.push(store_refused().await); + } + tokio::time::pause(); + let approve = Reply::Done { + rows: vec![row(None, true, true)], + overall: Overall::Approve, + }; + let fake = Fake::new(approve, vec![rules_json()]); + let poster = Flaky::new(failures); + let run = run(&fake, &fake, &fake, &poster, &request("r")).await; + assert_eq!(run.outcome, RunOutcome::PostFailed); + assert_eq!( + poster.tries.load(Ordering::SeqCst), + POST_RETRY_WAITS.len() + 1 + ); + assert!(poster.posted.0.lock().expect("unpoisoned").is_empty()); + assert!( + run.detail.as_deref().is_some_and(|d| d + .starts_with("posting the review failed: logging in to the swarm secret store")), + "{:?}", + run.detail + ); + } + #[tokio::test] async fn a_failed_record_write_still_posts_the_review() { let fake = Arc::new(Fake::new(