fix(server): Always apply cache debouncing for project states (#819)

Removes the `is_local` override for all project state sources for
multiple reasons:

- Reduces pressure on the Redis source.
- Reduces pressure on the contended project cache actor and the project
  sources.
- Applies equivalent caching across all sources.

CHANGELOG.md

@@ -2,8 +2,14 @@
 
 ## Unreleased
 
+**Features**:
+
 - Rename upstream retries histogram metric and add upstream requests duration metric. ([#816](https://github.com/getsentry/relay/pull/816))
 
+**Internal**:
+
+- Always apply cache debouncing for project states. This reduces pressure on the Redis and file system cache. ([#819](https://github.com/getsentry/relay/pull/819))
+
 ## 20.10.1
 
 **Internal**:

relay-server/src/actors/project.rs

@@ -409,7 +409,6 @@ pub struct Project {
     state: Option<Arc<ProjectState>>,
     state_channel: Option<Shared<oneshot::Receiver<Arc<ProjectState>>>>,
     rate_limits: RateLimits,
-    is_local: bool,
 }
 
 impl Project {
@@ -421,7 +420,6 @@ impl Project {
             state: None,
             state_channel: None,
             rate_limits: RateLimits::new(),
-            is_local: false,
         }
     }
 
@@ -441,19 +439,15 @@ impl Project {
             .map(|s| s.outdated(&self.config))
             .unwrap_or(Outdated::HardOutdated);
 
-        let alternative_rv = match (state, outdated, self.is_local) {
-            // The state is fetched from a local file, don't use own caching logic. Rely on
-            // `ProjectCache#local_states` for caching.
-            (_, _, true) => None,
-
+        let cached_state = match (state, outdated) {
             // There is no project state that can be used, fetch a state and return it.
-            (None, _, false) | (_, Outdated::HardOutdated, false) => None,
+            (None, _) | (_, Outdated::HardOutdated) => None,
 
             // The project is semi-outdated, fetch new state but return old one.
-            (Some(state), Outdated::SoftOutdated, false) => Some(state.clone()),
+            (Some(state), Outdated::SoftOutdated) => Some(state.clone()),
 
             // The project is not outdated, return early here to jump over fetching logic below.
-            (Some(state), Outdated::Updated, false) => return Response::ok(state.clone()),
+            (Some(state), Outdated::Updated) => return Response::ok(state.clone()),
         };
 
         let channel = match self.state_channel {
@@ -469,7 +463,7 @@ impl Project {
             }
         };
 
-        if let Some(rv) = alternative_rv {
+        if let Some(rv) = cached_state {
             return Response::ok(rv);
         }
 
@@ -492,10 +486,6 @@ impl Project {
             .into_actor(self)
             .map(move |state_result, slf, _ctx| {
                 slf.state_channel = None;
-                slf.is_local = state_result
-                    .as_ref()
-                    .map(|resp| resp.is_local)
-                    .unwrap_or(false);
                 slf.state = state_result.map(|resp| resp.state).ok();
 
                 if let Some(ref state) = slf.state {

relay-server/src/actors/project_cache.rs

@@ -176,22 +176,11 @@ pub struct FetchProjectState {
 #[derive(Debug)]
 pub struct ProjectStateResponse {
     pub state: Arc<ProjectState>,
-    pub is_local: bool,
 }
 
 impl ProjectStateResponse {
-    pub fn managed(state: Arc<ProjectState>) -> Self {
-        ProjectStateResponse {
-            state,
-            is_local: false,
-        }
-    }
-
-    pub fn local(state: Arc<ProjectState>) -> Self {
-        ProjectStateResponse {
-            state,
-            is_local: true,
-        }
+    pub fn new(state: Arc<ProjectState>) -> Self {
+        ProjectStateResponse { state }
     }
 }
 
@@ -239,23 +228,23 @@ impl Handler<FetchProjectState> for ProjectCache {
 
         let future = fetch_local.and_then(move |response| {
             if let Some(state) = response {
-                return Box::new(future::ok(ProjectStateResponse::local(state)))
+                return Box::new(future::ok(ProjectStateResponse::new(state)))
                     as ResponseFuture<_, _>;
             }
 
             match relay_mode {
                 RelayMode::Proxy => {
-                    return Box::new(future::ok(ProjectStateResponse::local(Arc::new(
+                    return Box::new(future::ok(ProjectStateResponse::new(Arc::new(
                         ProjectState::allowed(),
                     ))));
                 }
                 RelayMode::Static => {
-                    return Box::new(future::ok(ProjectStateResponse::local(Arc::new(
+                    return Box::new(future::ok(ProjectStateResponse::new(Arc::new(
                         ProjectState::missing(),
                     ))));
                 }
                 RelayMode::Capture => {
-                    return Box::new(future::ok(ProjectStateResponse::local(Arc::new(
+                    return Box::new(future::ok(ProjectStateResponse::new(Arc::new(
                         ProjectState::allowed(),
                     ))));
                 }
@@ -280,7 +269,7 @@ impl Handler<FetchProjectState> for ProjectCache {
 
             let fetch_redis = fetch_redis.and_then(move |response| {
                 if let Some(state) = response {
-                    return Box::new(future::ok(ProjectStateResponse::local(state)))
+                    return Box::new(future::ok(ProjectStateResponse::new(state)))
                         as ResponseFuture<_, _>;
                 }
 

relay-server/src/actors/project_upstream.rs

@@ -335,7 +335,7 @@ impl Handler<FetchProjectState> for UpstreamProjectSource {
             channel
                 .receiver()
                 .map_err(|_| ())
-                .map(|x| ProjectStateResponse::managed((*x).clone())),
+                .map(|x| ProjectStateResponse::new((*x).clone())),
         )
     }
 }

tests/integration/test_query.py

@@ -14,7 +14,10 @@
 
 def test_local_project_config(mini_sentry, relay):
     config = mini_sentry.basic_project_config()
-    relay = relay(mini_sentry, {"cache": {"file_interval": 1}}, wait_healthcheck=False)
+    relay_config = {
+        "cache": {"file_interval": 1, "project_expiry": 0, "project_grace_period": 0}
+    }
+    relay = relay(mini_sentry, relay_config, wait_healthcheck=False)
     relay.config_dir.mkdir("projects").join("42.json").write(
         json.dumps(
             {