avoid adding to 'uncleaned_roots' when generating index and caller passes accounts-db-skip-shrink (#25936)

runtime/src/accounts_db.rs

@@ -8084,6 +8084,7 @@ impl AccountsDb {
         limit_load_slot_count_from_snapshot: Option<usize>,
         verify: bool,
         genesis_config: &GenesisConfig,
+        accounts_db_skip_shrink: bool,
     ) -> IndexGenerationInfo {
         let mut slots = self.storage.all_slots();
         #[allow(clippy::stable_sort_primitive)]
@@ -8271,7 +8272,12 @@ impl AccountsDb {
             if pass == 0 {
                 // Need to add these last, otherwise older updates will be cleaned
                 for slot in &slots {
-                    self.accounts_index.add_root(*slot, false);
+                    // passing 'false' to 'add_root' causes all slots to be added to 'uncleaned_slots'
+                    // passing 'true' to 'add_root' does NOT add all slots to 'uncleaned_slots'
+                    // if we are skipping shrink, this potentially massive amount of work is never processed at startup, when all threads can be used.
+                    // This causes failures such as oom during the first bg clean, which is expecting to work in 'normal' operating circumstances.
+                    // So, don't add all slots to 'uncleaned_slots' here since by requesting to skip clean and shrink, caller is expecting the starting snapshot to be reasonable.
+                    self.accounts_index.add_root(*slot, accounts_db_skip_shrink);
                 }
 
                 self.set_storage_count_and_alive_bytes(storage_info, &mut timings);

runtime/src/bank.rs

@@ -6820,9 +6820,21 @@ impl Bank {
         last_full_snapshot_slot: Option<Slot>,
     ) -> bool {
         let mut clean_time = Measure::start("clean");
-        if !accounts_db_skip_shrink && self.slot() > 0 {
-            info!("cleaning..");
-            self.clean_accounts(true, true, last_full_snapshot_slot);
+        if !accounts_db_skip_shrink {
+            if self.slot() > 0 {
+                info!("cleaning..");
+                self.clean_accounts(true, true, last_full_snapshot_slot);
+            }
+        } else {
+            // if we are skipping shrink, there should be no uncleaned_roots deferred to later
+            assert_eq!(
+                self.rc
+                    .accounts
+                    .accounts_db
+                    .accounts_index
+                    .uncleaned_roots_len(),
+                0
+            );
         }
         clean_time.stop();
 

runtime/src/serde_snapshot.rs

@@ -242,6 +242,7 @@ pub(crate) fn bank_from_streams<R>(
     verify_index: bool,
     accounts_db_config: Option<AccountsDbConfig>,
     accounts_update_notifier: Option<AccountsUpdateNotifier>,
+    accounts_db_skip_shrink: bool,
 ) -> std::result::Result<Bank, Error>
 where
     R: Read,
@@ -280,6 +281,7 @@ where
                 verify_index,
                 accounts_db_config,
                 accounts_update_notifier,
+                accounts_db_skip_shrink,
             )?;
             Ok(bank)
         }};
@@ -488,6 +490,7 @@ fn reconstruct_bank_from_fields<E>(
     verify_index: bool,
     accounts_db_config: Option<AccountsDbConfig>,
     accounts_update_notifier: Option<AccountsUpdateNotifier>,
+    accounts_db_skip_shrink: bool,
 ) -> Result<Bank, Error>
 where
     E: SerializableStorage + std::marker::Sync,
@@ -504,6 +507,7 @@ where
         verify_index,
         accounts_db_config,
         accounts_update_notifier,
+        accounts_db_skip_shrink,
     )?;
 
     let bank_rc = BankRc::new(Accounts::new_empty(accounts_db), bank_fields.slot);
@@ -563,6 +567,7 @@ fn reconstruct_accountsdb_from_fields<E>(
     verify_index: bool,
     accounts_db_config: Option<AccountsDbConfig>,
     accounts_update_notifier: Option<AccountsUpdateNotifier>,
+    accounts_db_skip_shrink: bool,
 ) -> Result<(AccountsDb, ReconstructedAccountsDbInfo), Error>
 where
     E: SerializableStorage + std::marker::Sync,
@@ -712,6 +717,7 @@ where
         limit_load_slot_count_from_snapshot,
         verify_index,
         genesis_config,
+        accounts_db_skip_shrink,
     );
 
     accounts_db.maybe_add_filler_accounts(

runtime/src/serde_snapshot/tests.rs

@@ -88,6 +88,7 @@ where
         false,
         Some(crate::accounts_db::ACCOUNTS_DB_CONFIG_FOR_TESTING),
         None,
+        false,
     )
     .map(|(accounts_db, _)| accounts_db)
 }
@@ -300,6 +301,7 @@ fn test_bank_serialize_style(
         false,
         Some(crate::accounts_db::ACCOUNTS_DB_CONFIG_FOR_TESTING),
         None,
+        false,
     )
     .unwrap();
     dbank.src = ref_sc;
@@ -415,6 +417,7 @@ fn test_extra_fields_eof() {
         false,
         Some(crate::accounts_db::ACCOUNTS_DB_CONFIG_FOR_TESTING),
         None,
+        false,
     )
     .unwrap();
 
@@ -536,6 +539,7 @@ fn test_blank_extra_fields() {
         false,
         Some(crate::accounts_db::ACCOUNTS_DB_CONFIG_FOR_TESTING),
         None,
+        false,
     )
     .unwrap();
 

runtime/src/snapshot_utils.rs

@@ -821,6 +821,9 @@ pub fn bank_from_snapshot_archives(
         incremental_snapshot_archive_info,
     )?;
 
+    let accounts_db_skip_shrink =
+        accounts_db_skip_shrink || !full_snapshot_archive_info.is_remote();
+
     let parallel_divisions = std::cmp::min(
         PARALLEL_UNTAR_READERS_DEFAULT,
         std::cmp::max(1, num_cpus::get() / 4),
@@ -879,6 +882,7 @@ pub fn bank_from_snapshot_archives(
         verify_index,
         accounts_db_config,
         accounts_update_notifier,
+        accounts_db_skip_shrink,
     )?;
     measure_rebuild.stop();
     info!("{}", measure_rebuild);
@@ -886,7 +890,7 @@ pub fn bank_from_snapshot_archives(
     let mut measure_verify = Measure::start("verify");
     if !bank.verify_snapshot_bank(
         test_hash_calculation,
-        accounts_db_skip_shrink || !full_snapshot_archive_info.is_remote(),
+        accounts_db_skip_shrink,
         Some(full_snapshot_archive_info.slot()),
     ) && limit_load_slot_count_from_snapshot.is_none()
     {
@@ -1575,6 +1579,7 @@ fn rebuild_bank_from_snapshots(
     verify_index: bool,
     accounts_db_config: Option<AccountsDbConfig>,
     accounts_update_notifier: Option<AccountsUpdateNotifier>,
+    accounts_db_skip_shrink: bool,
 ) -> Result<Bank> {
     let (full_snapshot_version, full_snapshot_root_paths) =
         verify_unpacked_snapshots_dir_and_version(
@@ -1623,6 +1628,7 @@ fn rebuild_bank_from_snapshots(
                     verify_index,
                     accounts_db_config,
                     accounts_update_notifier,
+                    accounts_db_skip_shrink,
                 ),
             }?,
         )