Data column custody info (#7648)

#7647


  Introduces a new record in the blobs db `DataColumnCustodyInfo`

When `DataColumnCustodyInfo` exists in the db this indicates that a recent cgc change has occurred and/or that a custody backfill sync is currently in progress (custody backfill will be added as a separate PR). When a cgc change has occurred `earliest_available_slot` will be equal to the slot at which the cgc change occured. During custody backfill sync`earliest_available_slot` should be updated incrementally as it progresses.

~~Note that if `advertise_false_custody_group_count` is enabled we do not add a `DataColumnCustodyInfo` record in the db as that would affect the status v2 response.~~
(See comment https://github.com/sigp/lighthouse/pull/7648#discussion_r2212403389)

~~If `DataColumnCustodyInfo` doesn't exist in the db this indicates that we have fulfilled our custody requirements up to the DA window.~~
(It now always exist, and the slot will be set to `None` once backfill is complete)

StatusV2 now uses `DataColumnCustodyInfo` to calculate the `earliest_available_slot` if a `DataColumnCustodyInfo` record exists in the db, if it's `None`, then we return the `oldest_block_slot`.

beacon_node/beacon_chain/src/beacon_chain.rs

@@ -6807,6 +6807,15 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
             .map(|duration| (next_digest_epoch, duration))
     }
 
+    /// Update data column custody info with the slot at which cgc was changed.
+    pub fn update_data_column_custody_info(&self, slot: Option<Slot>) {
+        self.store
+            .put_data_column_custody_info(slot)
+            .unwrap_or_else(
+                |e| tracing::error!(error = ?e, "Failed to update data column custody info"),
+            );
+    }
+
     /// This method serves to get a sense of the current chain health. It is used in block proposal
     /// to determine whether we should outsource payload production duties.
     ///

beacon_node/beacon_chain/src/schema_change.rs

@@ -3,6 +3,7 @@ mod migration_schema_v23;
 mod migration_schema_v24;
 mod migration_schema_v25;
 mod migration_schema_v26;
+mod migration_schema_v27;
 
 use crate::beacon_chain::BeaconChainTypes;
 use std::sync::Arc;
@@ -67,6 +68,17 @@ pub fn migrate_schema<T: BeaconChainTypes>(
             let ops = migration_schema_v26::downgrade_from_v26::<T>(db.clone())?;
             db.store_schema_version_atomically(to, ops)
         }
+        (SchemaVersion(26), SchemaVersion(27)) => {
+            // This migration updates the blobs db. The schema version
+            // is bumped inside upgrade_to_v27.
+            migration_schema_v27::upgrade_to_v27::<T>(db.clone())
+        }
+        (SchemaVersion(27), SchemaVersion(26)) => {
+            // Downgrading is essentially a no-op and is only possible
+            // if peer das isn't scheduled.
+            migration_schema_v27::downgrade_from_v27::<T>(db.clone())?;
+            db.store_schema_version_atomically(to, vec![])
+        }
         // Anything else is an error.
         (_, _) => Err(HotColdDBError::UnsupportedSchemaVersion {
             target_version: to,

beacon_node/beacon_chain/src/schema_change/migration_schema_v27.rs

@@ -0,0 +1,26 @@
+use crate::BeaconChainTypes;
+use std::sync::Arc;
+use store::{metadata::SchemaVersion, Error, HotColdDB};
+
+/// Add `DataColumnCustodyInfo` entry to v27.
+pub fn upgrade_to_v27<T: BeaconChainTypes>(
+    db: Arc<HotColdDB<T::EthSpec, T::HotStore, T::ColdStore>>,
+) -> Result<(), Error> {
+    if db.spec.is_peer_das_scheduled() {
+        db.put_data_column_custody_info(None)?;
+        db.store_schema_version_atomically(SchemaVersion(27), vec![])?;
+    }
+
+    Ok(())
+}
+
+pub fn downgrade_from_v27<T: BeaconChainTypes>(
+    db: Arc<HotColdDB<T::EthSpec, T::HotStore, T::ColdStore>>,
+) -> Result<(), Error> {
+    if db.spec.is_peer_das_scheduled() {
+        return Err(Error::MigrationError(
+            "Cannot downgrade from v27 if peerDAS is scheduled".to_string(),
+        ));
+    }
+    Ok(())
+}

beacon_node/beacon_chain/src/validator_custody.rs

@@ -217,6 +217,7 @@ impl CustodyContext {
                     new_custody_group_count: updated_cgc,
                     sampling_count: self
                         .num_of_custody_groups_to_sample(Some(effective_epoch), spec),
+                    effective_epoch,
                 });
             }
         }
@@ -287,6 +288,7 @@ impl CustodyContext {
 pub struct CustodyCountChanged {
     pub new_custody_group_count: u64,
     pub sampling_count: u64,
+    pub effective_epoch: Epoch,
 }
 
 /// The custody information that gets persisted across runs.

beacon_node/beacon_chain/tests/schema_stability.rs

@@ -9,12 +9,14 @@ use operation_pool::PersistedOperationPool;
 use ssz::Encode;
 use std::sync::{Arc, LazyLock};
 use store::{
-    database::interface::BeaconNodeBackend, hot_cold_store::Split, metadata::DataColumnInfo,
+    database::interface::BeaconNodeBackend,
+    hot_cold_store::Split,
+    metadata::{DataColumnCustodyInfo, DataColumnInfo},
     DBColumn, HotColdDB, StoreConfig, StoreItem,
 };
 use strum::IntoEnumIterator;
 use tempfile::{tempdir, TempDir};
-use types::{ChainSpec, Hash256, Keypair, MainnetEthSpec};
+use types::{ChainSpec, Hash256, Keypair, MainnetEthSpec, Slot};
 
 type E = MainnetEthSpec;
 type Store<E> = Arc<HotColdDB<E, BeaconNodeBackend<E>, BeaconNodeBackend<E>>>;
@@ -84,11 +86,13 @@ async fn schema_stability() {
 
     chain.persist_op_pool().unwrap();
     chain.persist_custody_context().unwrap();
+    insert_data_column_custody_info(&store, &harness.spec);
 
     check_db_columns();
     check_metadata_sizes(&store);
     check_op_pool(&store);
     check_custody_context(&store, &harness.spec);
+    check_custody_info(&store, &harness.spec);
     check_persisted_chain(&store);
 
     // Not covered here:
@@ -100,13 +104,21 @@ async fn schema_stability() {
 fn check_db_columns() {
     let current_columns: Vec<&'static str> = DBColumn::iter().map(|c| c.as_str()).collect();
     let expected_columns = vec![
-        "bma", "blk", "blb", "bdc", "ste", "hsd", "hsn", "bsn", "bsd", "bss", "bs3", "bcs", "bst",
-        "exp", "bch", "opo", "etc", "frk", "pkc", "brp", "bsx", "bsr", "bbx", "bbr", "bhr", "brm",
-        "dht", "cus", "otb", "bhs", "olc", "lcu", "scb", "scm", "dmy",
+        "bma", "blk", "blb", "bdc", "bdi", "ste", "hsd", "hsn", "bsn", "bsd", "bss", "bs3", "bcs",
+        "bst", "exp", "bch", "opo", "etc", "frk", "pkc", "brp", "bsx", "bsr", "bbx", "bbr", "bhr",
+        "brm", "dht", "cus", "otb", "bhs", "olc", "lcu", "scb", "scm", "dmy",
     ];
     assert_eq!(expected_columns, current_columns);
 }
 
+fn insert_data_column_custody_info(store: &Store<E>, spec: &ChainSpec) {
+    if spec.is_peer_das_scheduled() {
+        store
+            .put_data_column_custody_info(Some(Slot::new(0)))
+            .unwrap();
+    }
+}
+
 /// Check the SSZ sizes of known on-disk metadata.
 ///
 /// New types can be added here as the schema evolves.
@@ -122,6 +134,7 @@ fn check_metadata_sizes(store: &Store<E>) {
         }
     );
     assert_eq!(DataColumnInfo::default().ssz_bytes_len(), 5);
+    assert_eq!(DataColumnCustodyInfo::default().ssz_bytes_len(), 5);
 }
 
 fn check_op_pool(store: &Store<E>) {
@@ -143,6 +156,15 @@ fn check_custody_context(store: &Store<E>, spec: &ChainSpec) {
     }
 }
 
+fn check_custody_info(store: &Store<E>, spec: &ChainSpec) {
+    let data_column_custody_info = store.get_data_column_custody_info().unwrap();
+    if spec.is_peer_das_scheduled() {
+        assert_eq!(data_column_custody_info.unwrap().as_ssz_bytes().len(), 13);
+    } else {
+        assert!(data_column_custody_info.is_none());
+    }
+}
+
 fn check_persisted_chain(store: &Store<E>) {
     let chain = store
         .get_item::<PersistedBeaconChain>(&Hash256::ZERO)

beacon_node/beacon_chain/tests/store_tests.rs

@@ -3157,7 +3157,11 @@ async fn schema_downgrade_to_min_version(
         )
         .await;
 
-    let min_version = SchemaVersion(22);
+    let min_version = if spec.is_fulu_scheduled() {
+        SchemaVersion(27)
+    } else {
+        SchemaVersion(22)
+    };
 
     // Save the slot clock so that the new harness doesn't revert in time.
     let slot_clock = harness.chain.slot_clock.clone();

beacon_node/http_api/src/lib.rs

@@ -3760,7 +3760,6 @@ pub fn serve<T: BeaconChainTypes>(
                                 .to_string(),
                         ));
                     }
-
                     Ok(())
                 })
             },
@@ -3845,6 +3844,12 @@ pub fn serve<T: BeaconChainTypes>(
                             current_slot,
                             &chain.spec,
                         ) {
+                            chain.update_data_column_custody_info(Some(
+                                cgc_change
+                                    .effective_epoch
+                                    .start_slot(T::EthSpec::slots_per_epoch()),
+                            ));
+
                             network_tx.send(NetworkMessage::CustodyCountChanged {
                                 new_custody_group_count: cgc_change.new_custody_group_count,
                                 sampling_count: cgc_change.sampling_count,

beacon_node/network/src/status.rs

@@ -29,8 +29,22 @@ pub(crate) fn status_message<T: BeaconChainTypes>(beacon_chain: &BeaconChain<T>)
         finalized_checkpoint.root = Hash256::zero();
     }
 
-    let earliest_available_slot = beacon_chain.store.get_anchor_info().oldest_block_slot;
+    // NOTE: We are making an assumption that `get_data_column_custody_info` wont fail.
+    let earliest_available_data_column_slot = beacon_chain
+        .store
+        .get_data_column_custody_info()
+        .ok()
+        .flatten()
+        .and_then(|info| info.earliest_data_column_slot);
 
+    // If data_column_custody_info.earliest_data_column_slot is `None`,
+    // no recent cgc changes have occurred and no cgc backfill is in progress.
+    let earliest_available_slot =
+        if let Some(earliest_available_data_column_slot) = earliest_available_data_column_slot {
+            earliest_available_data_column_slot
+        } else {
+            beacon_chain.store.get_anchor_info().oldest_block_slot
+        };
     StatusMessage::V2(StatusMessageV2 {
         fork_digest,
         finalized_root: finalized_checkpoint.root,

beacon_node/store/src/hot_cold_store.rs

@@ -6,10 +6,10 @@ use crate::historic_state_cache::HistoricStateCache;
 use crate::iter::{BlockRootsIterator, ParentRootBlockIterator, RootsIterator};
 use crate::memory_store::MemoryStore;
 use crate::metadata::{
-    AnchorInfo, BlobInfo, CompactionTimestamp, DataColumnInfo, SchemaVersion, ANCHOR_INFO_KEY,
-    ANCHOR_UNINITIALIZED, BLOB_INFO_KEY, COMPACTION_TIMESTAMP_KEY, CONFIG_KEY,
-    CURRENT_SCHEMA_VERSION, DATA_COLUMN_INFO_KEY, SCHEMA_VERSION_KEY, SPLIT_KEY,
-    STATE_UPPER_LIMIT_NO_RETAIN,
+    AnchorInfo, BlobInfo, CompactionTimestamp, DataColumnCustodyInfo, DataColumnInfo,
+    SchemaVersion, ANCHOR_INFO_KEY, ANCHOR_UNINITIALIZED, BLOB_INFO_KEY, COMPACTION_TIMESTAMP_KEY,
+    CONFIG_KEY, CURRENT_SCHEMA_VERSION, DATA_COLUMN_CUSTODY_INFO_KEY, DATA_COLUMN_INFO_KEY,
+    SCHEMA_VERSION_KEY, SPLIT_KEY, STATE_UPPER_LIMIT_NO_RETAIN,
 };
 use crate::state_cache::{PutStateOutcome, StateCache};
 use crate::{
@@ -91,6 +91,7 @@ struct BlockCache<E: EthSpec> {
     block_cache: LruCache<Hash256, SignedBeaconBlock<E>>,
     blob_cache: LruCache<Hash256, BlobSidecarList<E>>,
     data_column_cache: LruCache<Hash256, HashMap<ColumnIndex, Arc<DataColumnSidecar<E>>>>,
+    data_column_custody_info_cache: Option<DataColumnCustodyInfo>,
 }
 
 impl<E: EthSpec> BlockCache<E> {
@@ -99,6 +100,7 @@ impl<E: EthSpec> BlockCache<E> {
             block_cache: LruCache::new(size),
             blob_cache: LruCache::new(size),
             data_column_cache: LruCache::new(size),
+            data_column_custody_info_cache: None,
         }
     }
     pub fn put_block(&mut self, block_root: Hash256, block: SignedBeaconBlock<E>) {
@@ -112,6 +114,12 @@ impl<E: EthSpec> BlockCache<E> {
             .get_or_insert_mut(block_root, Default::default)
             .insert(data_column.index, data_column);
     }
+    pub fn put_data_column_custody_info(
+        &mut self,
+        data_column_custody_info: Option<DataColumnCustodyInfo>,
+    ) {
+        self.data_column_custody_info_cache = data_column_custody_info;
+    }
     pub fn get_block<'a>(&'a mut self, block_root: &Hash256) -> Option<&'a SignedBeaconBlock<E>> {
         self.block_cache.get(block_root)
     }
@@ -129,6 +137,9 @@ impl<E: EthSpec> BlockCache<E> {
             .get(block_root)
             .and_then(|map| map.get(column_index).cloned())
     }
+    pub fn get_data_column_custody_info(&self) -> Option<DataColumnCustodyInfo> {
+        self.data_column_custody_info_cache.clone()
+    }
     pub fn delete_block(&mut self, block_root: &Hash256) {
         let _ = self.block_cache.pop(block_root);
     }
@@ -922,6 +933,24 @@ impl<E: EthSpec, Hot: ItemStore<E>, Cold: ItemStore<E>> HotColdDB<E, Hot, Cold>
         ));
     }
 
+    pub fn put_data_column_custody_info(
+        &self,
+        earliest_data_column_slot: Option<Slot>,
+    ) -> Result<(), Error> {
+        let data_column_custody_info = DataColumnCustodyInfo {
+            earliest_data_column_slot,
+        };
+
+        self.blobs_db
+            .put(&DATA_COLUMN_CUSTODY_INFO_KEY, &data_column_custody_info)?;
+
+        self.block_cache
+            .lock()
+            .put_data_column_custody_info(Some(data_column_custody_info));
+
+        Ok(())
+    }
+
     pub fn put_data_columns(
         &self,
         block_root: &Hash256,
@@ -2389,6 +2418,27 @@ impl<E: EthSpec, Hot: ItemStore<E>, Cold: ItemStore<E>> HotColdDB<E, Hot, Cold>
             })
     }
 
+    /// Fetch custody info from the cache.
+    /// If custody info doesn't exist in the cache,
+    /// try to fetch from the DB and prime the cache.
+    pub fn get_data_column_custody_info(&self) -> Result<Option<DataColumnCustodyInfo>, Error> {
+        let Some(data_column_custody_info) = self.block_cache.lock().get_data_column_custody_info()
+        else {
+            let data_column_custody_info = self
+                .blobs_db
+                .get::<DataColumnCustodyInfo>(&DATA_COLUMN_CUSTODY_INFO_KEY)?;
+
+            // Update the cache
+            self.block_cache
+                .lock()
+                .put_data_column_custody_info(data_column_custody_info.clone());
+
+            return Ok(data_column_custody_info);
+        };
+
+        Ok(Some(data_column_custody_info))
+    }
+
     /// Fetch all columns for a given block from the store.
     pub fn get_data_columns(
         &self,

beacon_node/store/src/lib.rs

@@ -264,6 +264,8 @@ pub enum DBColumn {
     BeaconBlob,
     #[strum(serialize = "bdc")]
     BeaconDataColumn,
+    #[strum(serialize = "bdi")]
+    BeaconDataColumnCustodyInfo,
     /// For full `BeaconState`s in the hot database (finalized or fork-boundary states).
     ///
     /// DEPRECATED.
@@ -424,6 +426,7 @@ impl DBColumn {
             | Self::CustodyContext
             | Self::OptimisticTransitionBlock => 32,
             Self::BeaconBlockRoots
+            | Self::BeaconDataColumnCustodyInfo
             | Self::BeaconBlockRootsChunked
             | Self::BeaconStateRoots
             | Self::BeaconStateRootsChunked

beacon_node/store/src/metadata.rs

@@ -4,7 +4,7 @@ use ssz::{Decode, Encode};
 use ssz_derive::{Decode, Encode};
 use types::{Hash256, Slot};
 
-pub const CURRENT_SCHEMA_VERSION: SchemaVersion = SchemaVersion(26);
+pub const CURRENT_SCHEMA_VERSION: SchemaVersion = SchemaVersion(27);
 
 // All the keys that get stored under the `BeaconMeta` column.
 //
@@ -18,6 +18,7 @@ pub const COMPACTION_TIMESTAMP_KEY: Hash256 = Hash256::repeat_byte(4);
 pub const ANCHOR_INFO_KEY: Hash256 = Hash256::repeat_byte(5);
 pub const BLOB_INFO_KEY: Hash256 = Hash256::repeat_byte(6);
 pub const DATA_COLUMN_INFO_KEY: Hash256 = Hash256::repeat_byte(7);
+pub const DATA_COLUMN_CUSTODY_INFO_KEY: Hash256 = Hash256::repeat_byte(8);
 
 /// State upper limit value used to indicate that a node is not storing historic states.
 pub const STATE_UPPER_LIMIT_NO_RETAIN: Slot = Slot::new(u64::MAX);
@@ -204,6 +205,30 @@ impl StoreItem for BlobInfo {
     }
 }
 
+/// Database parameter relevant to data column custody sync. There is only at most a single
+/// `DataColumnCustodyInfo` stored in the db. `earliest_data_column_slot` is updated when cgc
+/// count changes and is updated incrementally during data column custody backfill. Once custody backfill
+/// is complete `earliest_data_column_slot` is set to `None`.
+#[derive(Debug, PartialEq, Eq, Clone, Encode, Decode, Serialize, Deserialize, Default)]
+pub struct DataColumnCustodyInfo {
+    /// The earliest slot for which data columns are available.
+    pub earliest_data_column_slot: Option<Slot>,
+}
+
+impl StoreItem for DataColumnCustodyInfo {
+    fn db_column() -> DBColumn {
+        DBColumn::BeaconDataColumnCustodyInfo
+    }
+
+    fn as_store_bytes(&self) -> Vec<u8> {
+        self.as_ssz_bytes()
+    }
+
+    fn from_store_bytes(bytes: &[u8]) -> Result<Self, Error> {
+        Ok(DataColumnCustodyInfo::from_ssz_bytes(bytes)?)
+    }
+}
+
 /// Database parameters relevant to data column sync.
 #[derive(Debug, PartialEq, Eq, Clone, Encode, Decode, Serialize, Deserialize, Default)]
 pub struct DataColumnInfo {