Fix anchor archives

Author: michaelsproul

beacon_node/beacon_chain/src/schema_change/migration_schema_v22.rs

@@ -3,9 +3,7 @@ use std::sync::Arc;
 use store::chunked_iter::ChunkedVectorIter;
 use store::{
     chunked_vector::BlockRootsChunked,
-    metadata::{
-        SchemaVersion, ANCHOR_FOR_ARCHIVE_NODE, ANCHOR_UNINITIALIZED, STATE_UPPER_LIMIT_NO_RETAIN,
-    },
+    metadata::{SchemaVersion, ANCHOR_UNINITIALIZED, STATE_UPPER_LIMIT_NO_RETAIN},
     partial_beacon_state::PartialBeaconState,
     AnchorInfo, DBColumn, Error, HotColdDB, KeyValueStore, KeyValueStoreOp,
 };
@@ -48,7 +46,13 @@ pub fn upgrade_to_v22<T: BeaconChainTypes>(
     // If the anchor was uninitialized in the old schema (`None`), this represents a full archive
     // node.
     let effective_anchor = if old_anchor == ANCHOR_UNINITIALIZED {
-        ANCHOR_FOR_ARCHIVE_NODE
+        AnchorInfo {
+            anchor_slot: Slot::new(0),
+            oldest_block_slot: Slot::new(0),
+            oldest_block_parent: Hash256::ZERO,
+            state_upper_limit: Slot::new(0),
+            state_lower_limit: Slot::new(0),
+        }
     } else {
         old_anchor.clone()
     };

beacon_node/store/src/config.rs

@@ -247,7 +247,7 @@ impl StoreItem for OnDiskStoreConfig {
 mod test {
     use super::*;
     use crate::{
-        metadata::{ANCHOR_FOR_ARCHIVE_NODE, ANCHOR_UNINITIALIZED, STATE_UPPER_LIMIT_NO_RETAIN},
+        metadata::{ANCHOR_UNINITIALIZED, STATE_UPPER_LIMIT_NO_RETAIN},
         AnchorInfo, Split,
     };
     use ssz::DecodeError;
@@ -291,8 +291,15 @@ mod test {
             slot: Slot::new(32),
             ..Default::default()
         };
+        let anchor = AnchorInfo {
+            anchor_slot: Slot::new(0),
+            oldest_block_slot: Slot::new(0),
+            oldest_block_parent: Hash256::ZERO,
+            state_upper_limit: Slot::new(0),
+            state_lower_limit: Slot::new(0),
+        };
         assert!(store_config
-            .check_compatibility(&on_disk_config, &split, &ANCHOR_FOR_ARCHIVE_NODE)
+            .check_compatibility(&on_disk_config, &split, &anchor)
             .is_err());
     }
 

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_FOR_ARCHIVE_NODE, 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, 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,
 };
 use crate::state_cache::{PutStateOutcome, StateCache};
 use crate::{
@@ -2536,17 +2536,12 @@ impl<E: EthSpec, Hot: ItemStore<E>, Cold: ItemStore<E>> HotColdDB<E, Hot, Cold>
         } else {
             next_snapshot_slot
         };
-        let anchor_info = if state_upper_limit == 0 && anchor_slot == 0 {
-            // Genesis archive node: no anchor because we *will* store all states.
-            ANCHOR_FOR_ARCHIVE_NODE
-        } else {
-            AnchorInfo {
-                anchor_slot,
-                oldest_block_slot,
-                oldest_block_parent,
-                state_upper_limit,
-                state_lower_limit: self.spec.genesis_slot,
-            }
+        let anchor_info = AnchorInfo {
+            anchor_slot,
+            oldest_block_slot,
+            oldest_block_parent,
+            state_upper_limit,
+            state_lower_limit: self.spec.genesis_slot,
         };
         self.compare_and_set_anchor_info(ANCHOR_UNINITIALIZED, anchor_info)
     }

beacon_node/store/src/metadata.rs

@@ -22,15 +22,6 @@ pub const DATA_COLUMN_INFO_KEY: Hash256 = Hash256::repeat_byte(7);
 /// 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);
 
-/// The `AnchorInfo` encoding full availability of all historic blocks & states.
-pub const ANCHOR_FOR_ARCHIVE_NODE: AnchorInfo = AnchorInfo {
-    anchor_slot: Slot::new(0),
-    oldest_block_slot: Slot::new(0),
-    oldest_block_parent: Hash256::ZERO,
-    state_upper_limit: Slot::new(0),
-    state_lower_limit: Slot::new(0),
-};
-
 /// The `AnchorInfo` encoding an uninitialized anchor.
 ///
 /// This value should never exist except on initial start-up prior to the anchor being initialised
@@ -153,6 +144,21 @@ impl AnchorInfo {
     pub fn full_state_pruning_enabled(&self) -> bool {
         self.state_lower_limit == 0 && self.state_upper_limit == STATE_UPPER_LIMIT_NO_RETAIN
     }
+
+    /// Compute the correct `AnchorInfo` for an archive node created from the current node.
+    ///
+    /// This method ensures that the `anchor_slot` which is used for the hot database's diff grid is
+    /// preserved.
+    pub fn as_archive_anchor(&self) -> Self {
+        Self {
+            // Anchor slot MUST be the same. It is immutable.
+            anchor_slot: self.anchor_slot,
+            oldest_block_slot: Slot::new(0),
+            oldest_block_parent: Hash256::ZERO,
+            state_upper_limit: Slot::new(0),
+            state_lower_limit: Slot::new(0),
+        }
+    }
 }
 
 impl StoreItem for AnchorInfo {

beacon_node/store/src/reconstruct.rs

@@ -1,6 +1,5 @@
 //! Implementation of historic state reconstruction (given complete block history).
 use crate::hot_cold_store::{HotColdDB, HotColdDBError};
-use crate::metadata::ANCHOR_FOR_ARCHIVE_NODE;
 use crate::metrics;
 use crate::{Error, ItemStore};
 use itertools::{process_results, Itertools};
@@ -145,10 +144,8 @@ where
                             });
                         }
 
-                        self.compare_and_set_anchor_info_with_write(
-                            old_anchor,
-                            ANCHOR_FOR_ARCHIVE_NODE,
-                        )?;
+                        let new_anchor = old_anchor.as_archive_anchor();
+                        self.compare_and_set_anchor_info_with_write(old_anchor, new_anchor)?;
 
                         return Ok(());
                     } else {