Removed metastore -> controlplane event flow via the EventBroker. (#3880

)

The two internal actors are replaced by two internal states.

Their execution is not concurrent anymore,
but we the code and the flow is simplified and we avoid some race conditions.

The control plane is not getting the update notify signal through the
broker anymore.

The Notify RPC is entirely removed.

Most of the test in the indexer scheduler become Control plane tests.

quickwit/quickwit-common/src/progress.rs

@@ -20,6 +20,8 @@
 use std::sync::atomic::{AtomicU32, Ordering};
 use std::sync::Arc;
 
+use futures::Future;
+
 /// Progress makes it possible to register some progress.
 /// It is used in lieu of healthcheck.
 ///
@@ -83,6 +85,13 @@ impl Progress {
             .fetch_max(ProgressState::Updated.into(), Ordering::Relaxed);
     }
 
+    /// Executes a future in a protected zone.
+    pub async fn protect_future<Fut, T>(&self, future: Fut) -> T
+    where Fut: Future<Output = T> {
+        let _guard = self.protect_zone();
+        future.await
+    }
+
     pub fn protect_zone(&self) -> ProtectedZoneGuard {
         loop {
             let previous_state: ProgressState = self.0.load(Ordering::SeqCst).into();