1992-custom-snapshot-intervals

cardano-chain-gen/test/Test/Cardano/Db/Mock/Config.hs

@@ -295,8 +295,6 @@ mkSyncNodeParams staticDir mutableDir CommandLineArgs {..} = do
       , enpHasCache = claHasCache
       , enpForceIndexes = claForceIndexes
       , enpHasInOut = True
-      , enpSnEveryFollowing = 35
-      , enpSnEveryLagging = 35
       , enpMaybeRollback = Nothing
       }
 

cardano-db-sync/app/cardano-db-sync.hs

@@ -89,8 +89,6 @@ pRunDbSyncNode = do
     <*> pHasCache
     <*> pForceIndexes
     <*> pHasInOut
-    <*> pure 500
-    <*> pure 10000
     <*> optional pRollbackSlotNo
 
 pConfigFile :: Parser ConfigFile

cardano-db-sync/src/Cardano/DbSync.hs

@@ -295,8 +295,7 @@ extractSyncOptions snp aop snc =
           isTxOutConsumedBootstrap'
           forceTxIn'
     , soptInsertOptions = iopts
-    , snapshotEveryFollowing = enpSnEveryFollowing snp
-    , snapshotEveryLagging = enpSnEveryLagging snp
+    , soptSnapshotInterval = dncSnapshotInterval snc
     }
   where
     maybeKeepMNames =

cardano-db-sync/src/Cardano/DbSync/Api/Types.hs

@@ -28,7 +28,7 @@ import Ouroboros.Network.Magic (NetworkMagic (..))
 
 import qualified Cardano.Db as DB
 import Cardano.DbSync.Cache.Types (CacheStatistics, CacheStatus)
-import Cardano.DbSync.Config.Types (SyncNodeConfig)
+import Cardano.DbSync.Config.Types (SnapshotIntervalConfig, SyncNodeConfig)
 import Cardano.DbSync.Ledger.Types (HasLedgerEnv)
 import Cardano.DbSync.LocalStateQuery (NoLedgerEnv)
 import Cardano.DbSync.Types (
@@ -70,8 +70,7 @@ data SyncOptions = SyncOptions
   , soptCache :: !Bool
   , soptPruneConsumeMigration :: !DB.PruneConsumeMigration
   , soptInsertOptions :: !InsertOptions
-  , snapshotEveryFollowing :: !Word64
-  , snapshotEveryLagging :: !Word64
+  , soptSnapshotInterval :: !SnapshotIntervalConfig
   }
   deriving (Show)
 

cardano-db-sync/src/Cardano/DbSync/Config.hs

@@ -92,6 +92,7 @@ coalesceConfig pcfg ncfg adjustGenesisPath = do
       , dncConwayHardFork = ncConwayHardFork ncfg
       , dncInsertOptions = extractInsertOptions pcfg
       , dncIpfsGateway = endsInSlash <$> pcIpfsGateway pcfg
+      , dncSnapshotInterval = pcSnapshotInterval pcfg
       }
 
 mkAdjustPath :: SyncPreConfig -> (FilePath -> FilePath)

cardano-db-sync/src/Cardano/DbSync/Config/Types.hs

@@ -39,6 +39,7 @@ module Cardano.DbSync.Config.Types (
   GovernanceConfig (..),
   OffchainPoolDataConfig (..),
   JsonTypeConfig (..),
+  SnapshotIntervalConfig (..),
   LedgerStateDir (..),
   LogFileDir (..),
   NetworkName (..),
@@ -109,8 +110,6 @@ data SyncNodeParams = SyncNodeParams
   , enpHasCache :: !Bool
   , enpForceIndexes :: !Bool
   , enpHasInOut :: !Bool
-  , enpSnEveryFollowing :: !Word64
-  , enpSnEveryLagging :: !Word64
   , enpMaybeRollback :: !(Maybe SlotNo)
   }
   deriving (Show)
@@ -147,6 +146,7 @@ data SyncNodeConfig = SyncNodeConfig
   , dncConwayHardFork :: !(CardanoHardForkTrigger (ShelleyBlock (Praos StandardCrypto) ConwayEra))
   , dncInsertOptions :: !SyncInsertOptions
   , dncIpfsGateway :: [Text]
+  , dncSnapshotInterval :: !SnapshotIntervalConfig
   }
 
 data SyncPreConfig = SyncPreConfig
@@ -159,6 +159,7 @@ data SyncPreConfig = SyncPreConfig
   , pcPrometheusPort :: !Int
   , pcInsertConfig :: !SyncInsertConfig
   , pcIpfsGateway :: ![Text]
+  , pcSnapshotInterval :: !SnapshotIntervalConfig
   }
   deriving (Show)
 
@@ -279,6 +280,12 @@ data JsonTypeConfig
   | JsonTypeDisable
   deriving (Eq, Show)
 
+data SnapshotIntervalConfig = SnapshotIntervalConfig
+  { sicFollowing :: !Word64
+  , sicLagging :: !Word64
+  }
+  deriving (Eq, Show)
+
 newtype GenesisFile = GenesisFile
   { unGenesisFile :: FilePath
   }
@@ -407,6 +414,7 @@ parseGenSyncNodeConfig o =
     <*> fmap (fromMaybe 8080) (o .:? "PrometheusPort")
     <*> o .:? "insert_options" .!= def
     <*> o .:? "ipfs_gateway" .!= ["https://ipfs.io/ipfs"]
+    <*> o .:? "snapshot_interval" .!= def
 
 instance FromJSON SyncProtocol where
   parseJSON o =
@@ -728,6 +736,26 @@ instance FromJSON JsonTypeConfig where
     "disable" -> pure JsonTypeDisable
     other -> fail $ "unexpected json_type: " <> show other
 
+instance ToJSON SnapshotIntervalConfig where
+  toJSON cfg =
+    Aeson.object
+      [ "following" .= sicFollowing cfg
+      , "lagging" .= sicLagging cfg
+      ]
+
+instance FromJSON SnapshotIntervalConfig where
+  parseJSON = Aeson.withObject "snapshot_interval" $ \obj ->
+    SnapshotIntervalConfig
+      <$> obj .: "following"
+      <*> obj .: "lagging"
+
+instance Default SnapshotIntervalConfig where
+  def =
+    SnapshotIntervalConfig
+      { sicFollowing = 500 -- Every 500 blocks when near tip
+      , sicLagging = 100000 -- Every 100,000 blocks when syncing (less frequent)
+      }
+
 instance Default SyncInsertConfig where
   def = SyncInsertConfig Nothing def
 

cardano-db-sync/src/Cardano/DbSync/Ledger/State.hs

@@ -186,8 +186,8 @@ mkHasLedgerEnv trce protoInfo dir nw systemStart syncOptions = do
       , leNetwork = nw
       , leSystemStart = systemStart
       , leAbortOnPanic = soptAbortOnInvalid syncOptions
-      , leSnapshotEveryFollowing = snapshotEveryFollowing syncOptions
-      , leSnapshotEveryLagging = snapshotEveryLagging syncOptions
+      , leSnapshotEveryFollowing = sicFollowing $ soptSnapshotInterval syncOptions
+      , leSnapshotEveryLagging = sicLagging $ soptSnapshotInterval syncOptions
       , leInterpreter = intervar
       , leStateVar = svar
       , leStateWriteQueue = swQueue
@@ -330,7 +330,8 @@ storeSnapshotAndCleanupMaybe env oldState appResult blkNo isCons syncState =
     Just newEpoch
       | newEpochNo <- unEpochNo (Generic.neEpoch newEpoch)
       , newEpochNo > 0
-      , isCons || (newEpochNo `mod` 10 == 0) || newEpochNo >= 530 ->
+      , -- Snapshot every epoch when near tip, every 10 epochs when lagging, or always for epoch >= 580
+        (isCons && syncState == SyncFollowing) || (newEpochNo `mod` 10 == 0) || newEpochNo >= 580 ->
           do
             -- TODO: Instead of newEpochNo - 1, is there any way to get the epochNo from 'lssOldState'?
             liftIO $ saveCleanupState env oldState (Just $ EpochNo $ newEpochNo - 1)
@@ -403,7 +404,8 @@ ledgerStateWriteLoop tracer swQueue codecConfig =
 
 mkLedgerStateFilename :: LedgerStateDir -> ExtLedgerState CardanoBlock -> Maybe EpochNo -> WithOrigin FilePath
 mkLedgerStateFilename dir ledger mEpochNo =
-  lsfFilePath . dbPointToFileName dir mEpochNo
+  lsfFilePath
+    . dbPointToFileName dir mEpochNo
     <$> getPoint (ledgerTipPoint @CardanoBlock (ledgerState ledger))
 
 saveCleanupState :: HasLedgerEnv -> CardanoLedgerState -> Maybe EpochNo -> IO ()

cardano-db-sync/test/Cardano/DbSync/Gen.hs

@@ -58,6 +58,13 @@ syncPreConfig =
     <*> Gen.int (Range.linear 0 10000)
     <*> syncInsertConfig
     <*> Gen.list (Range.linear 0 10) (Gen.text (Range.linear 0 100) Gen.unicode)
+    <*> snapshotIntervalConfig
+
+snapshotIntervalConfig :: Gen SnapshotIntervalConfig
+snapshotIntervalConfig =
+  SnapshotIntervalConfig
+    <$> Gen.word64 (Range.linear 100 1000)
+    <*> Gen.word64 (Range.linear 10000 100000)
 
 syncNodeParams :: MonadGen m => m SyncNodeParams
 syncNodeParams =
@@ -71,8 +78,6 @@ syncNodeParams =
     <*> Gen.bool
     <*> Gen.bool
     <*> Gen.bool
-    <*> Gen.word64 (Range.linear 0 1000)
-    <*> Gen.word64 (Range.linear 0 1000)
     <*> pure Nothing
 
 syncNodeConfig :: Logging.Configuration -> Gen SyncNodeConfig
@@ -104,6 +109,7 @@ syncNodeConfig loggingCfg =
     <*> triggerHardFork
     <*> syncInsertOptions
     <*> pure []
+    <*> snapshotIntervalConfig
 
 syncInsertConfig :: Gen SyncInsertConfig
 syncInsertConfig =

doc/configuration.md

@@ -66,6 +66,7 @@ Below is a sample `insert_options` section that shows all the defaults:
 | [pool\_stat](#pool-stat)                     | `enum`     | Optional |
 | [remove\_jsonb_from_schema](#remove-jsonb-from-schema) | `enum`     | Optional |
 | [stop\_at\_block](#stop-at-block)            | `integer`  | Optional |
+| [snapshot\_interval](#snapshot-interval)     | `object`   | Optional |
 
 ## Preset
 
@@ -602,3 +603,55 @@ Stops db-sync after processing the specified block number. Useful for testing an
 }
 ```
 
+## Snapshot Interval
+
+`snapshot_interval`
+
+* Type: `object`
+* Optional: When not specified, uses default values
+
+Controls how frequently ledger state snapshots are taken during sync. Taking snapshots less frequently during initial sync can significantly improve sync performance by reducing IOPS and disk throughput consumption.
+
+Snapshot Interval Properties:
+
+| Property                         | Type      | Required | Default |
+| :------------------------------- | :-------- | :------- | :------ |
+| [following](#following)          | `integer` | Optional | 500     |
+| [lagging](#lagging)              | `integer` | Optional | 100000  |
+
+### Following
+
+`snapshot_interval.following`
+
+* Type: `integer`
+* Default: `500`
+
+Number of blocks between snapshots when db-sync is near the tip of the chain (within approximately 10 minutes). More frequent snapshots when following the tip ensure faster recovery from rollbacks.
+
+### Lagging
+
+`snapshot_interval.lagging`
+
+* Type: `integer`
+* Default: `100000`
+
+Number of blocks between snapshots when db-sync is syncing and significantly behind the tip of the chain. Less frequent snapshots during initial sync improves performance by reducing expensive disk operations.
+
+### Example
+
+```json
+{
+  "snapshot_interval": {
+    "following": 500,
+    "lagging": 100000
+  }
+}
+```
+
+### Performance Considerations
+
+- **Smaller `following` value**: Faster recovery from rollbacks when near the tip, but more frequent disk writes
+- **Larger `lagging` value**: Faster initial sync with reduced IOPS, but slower recovery if rollback is needed during sync
+- **Recommended for initial sync**: Use a large `lagging` value (50000-100000) to maximise sync speed
+- **Recommended when near tip**: Use a small `following` value (500-1000) to enable quick rollback recovery
+