Merge pull request #3372 from input-output-hk/djo/3333/aggregator-state-machine-blocked-state

feat(aggregator): add state machine `blocked` state

Author: Alenar

Cargo.lock

@@ -98,7 +98,7 @@ The Mithril aggregator's **REST API** documentation can be found here :
 
 - A runtime powered by a state machine:
   - The runtime operates synchronously and is scheduled to execute at regular intervals
-  - It encompasses three potential states: **IDLE**, **READY**, and **SIGNING**
+  - It encompasses four potential states: **IDLE**, **BLOCKED**, **READY**, and **SIGNING**
   - The runtime effectively manages state transitions
   - The runtime structure is illustrated in the diagram below:
 

docs/website/root/mithril/advanced/mithril-network/aggregator.md

@@ -1,6 +1,6 @@
 [package]
 name = "mithril-aggregator"
-version = "0.9.16"
+version = "0.9.17"
 description = "A Mithril Aggregator server"
 authors = { workspace = true }
 edition = { workspace = true }

docs/website/root/mithril/advanced/mithril-network/images/aggregator-runtime.jpg

@@ -0,0 +1,18 @@
+//! Aggregator specific certificate chain validation errors
+
+use thiserror::Error;
+
+use mithril_common::entities::Epoch;
+
+/// Error raised when the local certificate chain has an epoch gap.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Error)]
+#[error(
+    "There is an epoch gap between the last certificate epoch ({certificate_epoch:?}) and current epoch ({current_epoch:?}). A leader aggregator must be re-genesis by the owner of the genesis keys, a follower aggregator will automatically catchup with the leader's certificate chain."
+)]
+pub struct CertificateEpochGap {
+    /// Epoch of the last issued certificate.
+    pub certificate_epoch: Epoch,
+
+    /// Given current epoch.
+    pub current_epoch: Epoch,
+}

mithril-aggregator/Cargo.toml

@@ -3,12 +3,14 @@
 //! This module provide domain entities for the services & state machine.
 //!
 mod aggregator_epoch_settings;
+mod certificate_chain_error;
 mod leader_aggregator_epoch_settings;
 mod open_message;
 mod signer_registration_message;
 mod signer_ticker_message;
 
 pub use aggregator_epoch_settings::AggregatorEpochSettings;
+pub use certificate_chain_error::*;
 pub use leader_aggregator_epoch_settings::LeaderAggregatorEpochSettings;
 pub use open_message::OpenMessage;
 pub use signer_registration_message::{

mithril-aggregator/src/entities/certificate_chain_error.rs

@@ -51,6 +51,9 @@ pub trait AggregatorRunnerTrait: Sync + Send {
         current_time_point: &TimePoint,
     ) -> StdResult<Option<OpenMessage>>;
 
+    /// Returns the epoch of the last genesis certificate, if any.
+    async fn last_genesis_certificate_epoch(&self) -> StdResult<Option<Epoch>>;
+
     /// Check if a certificate chain is valid.
     async fn is_certificate_chain_valid(&self, time_point: &TimePoint) -> StdResult<()>;
 
@@ -75,6 +78,7 @@ pub trait AggregatorRunnerTrait: Sync + Send {
     /// Synchronize the follower aggregator certificate chain
     async fn synchronize_follower_aggregator_certificate_chain(
         &self,
+        time_point: &TimePoint,
         force_sync: bool,
     ) -> StdResult<()>;
 
@@ -232,6 +236,17 @@ impl AggregatorRunnerTrait for AggregatorRunner {
         Ok(None)
     }
 
+    async fn last_genesis_certificate_epoch(&self) -> StdResult<Option<Epoch>> {
+        debug!(self.logger, ">> last_genesis_certificate_epoch");
+        let epoch = self
+            .dependencies
+            .certificate_repository
+            .get_latest_genesis_certificate::<Certificate>()
+            .await?
+            .map(|c| c.epoch);
+        Ok(epoch)
+    }
+
     async fn is_certificate_chain_valid(&self, time_point: &TimePoint) -> StdResult<()> {
         debug!(self.logger, ">> is_certificate_chain_valid");
         self.dependencies
@@ -502,6 +517,7 @@ impl AggregatorRunnerTrait for AggregatorRunner {
 
     async fn synchronize_follower_aggregator_certificate_chain(
         &self,
+        time_point: &TimePoint,
         force_sync: bool,
     ) -> StdResult<()> {
         debug!(
@@ -510,7 +526,7 @@ impl AggregatorRunnerTrait for AggregatorRunner {
         );
         self.dependencies
             .certificate_chain_synchronizer
-            .synchronize_certificate_chain(force_sync)
+            .synchronize_certificate_chain(time_point.epoch, force_sync)
             .await
     }
 }