Delete old checkpoints in stateDB automatically

Introduce a constructor parameter for the StateDB called `keep`, which tells
how many checkpoints to keep.  When doing a new checkpoint, if the number of
existing checkpoints exeeds `keep`, the oldest ones will be deleted.

api/api_test.go

@@ -212,7 +212,7 @@ func TestMain(m *testing.M) {
 		}
 	}()
 	chainID := uint16(0)
-	sdb, err := statedb.NewStateDB(dir, statedb.TypeTxSelector, 0, chainID)
+	sdb, err := statedb.NewStateDB(dir, 128, statedb.TypeTxSelector, 0, chainID)
 	if err != nil {
 		panic(err)
 	}

batchbuilder/batchbuilder.go

@@ -29,7 +29,8 @@ type ConfigBatch struct {
 // NewBatchBuilder constructs a new BatchBuilder, and executes the bb.Reset
 // method
 func NewBatchBuilder(dbpath string, synchronizerStateDB *statedb.StateDB, configCircuits []ConfigCircuit, batchNum common.BatchNum, nLevels uint64) (*BatchBuilder, error) {
-	localStateDB, err := statedb.NewLocalStateDB(dbpath, synchronizerStateDB, statedb.TypeBatchBuilder, int(nLevels))
+	localStateDB, err := statedb.NewLocalStateDB(dbpath, 128, synchronizerStateDB,
+		statedb.TypeBatchBuilder, int(nLevels))
 	if err != nil {
 		return nil, tracerr.Wrap(err)
 	}

batchbuilder/batchbuilder_test.go

@@ -16,7 +16,7 @@ func TestBatchBuilder(t *testing.T) {
 	defer assert.Nil(t, os.RemoveAll(dir))
 
 	chainID := uint16(0)
-	synchDB, err := statedb.NewStateDB(dir, statedb.TypeBatchBuilder, 0, chainID)
+	synchDB, err := statedb.NewStateDB(dir, 128, statedb.TypeBatchBuilder, 0, chainID)
 	assert.Nil(t, err)
 
 	bbDir, err := ioutil.TempDir("", "tmpBatchBuilderDB")

cli/node/cfg.buidler.toml

@@ -14,6 +14,7 @@ APIAddress = "localhost:12345"
 
 [StateDB]
 Path = "/tmp/iden3-test/hermez/statedb"
+Keep = 256
 
 [PostgreSQL]
 Port     = 5432

config/config.go

@@ -102,7 +102,8 @@ type Node struct {
 		Type     string   `valudate:"required"`
 	} `validate:"required"`
 	StateDB struct {
-		Path string
+		Path string `validate:"required"`
+		Keep int    `validate:"required"`
 	} `validate:"required"`
 	PostgreSQL struct {
 		Port     int    `validate:"required"`

coordinator/coordinator_test.go

@@ -98,7 +98,7 @@ func newTestModules(t *testing.T) modules {
 	syncDBPath, err = ioutil.TempDir("", "tmpSyncDB")
 	require.NoError(t, err)
 	deleteme = append(deleteme, syncDBPath)
-	syncStateDB, err := statedb.NewStateDB(syncDBPath, statedb.TypeSynchronizer, 48, chainID)
+	syncStateDB, err := statedb.NewStateDB(syncDBPath, 128, statedb.TypeSynchronizer, 48, chainID)
 	assert.NoError(t, err)
 
 	pass := os.Getenv("POSTGRES_PASS")

coordinator/purger_test.go

@@ -28,12 +28,12 @@ func newStateDB(t *testing.T) *statedb.LocalStateDB {
 	syncDBPath, err := ioutil.TempDir("", "tmpSyncDB")
 	require.NoError(t, err)
 	deleteme = append(deleteme, syncDBPath)
-	syncStateDB, err := statedb.NewStateDB(syncDBPath, statedb.TypeSynchronizer, 48, chainID)
+	syncStateDB, err := statedb.NewStateDB(syncDBPath, 128, statedb.TypeSynchronizer, 48, chainID)
 	assert.NoError(t, err)
 	stateDBPath, err := ioutil.TempDir("", "tmpStateDB")
 	require.NoError(t, err)
 	deleteme = append(deleteme, stateDBPath)
-	stateDB, err := statedb.NewLocalStateDB(stateDBPath, syncStateDB, statedb.TypeTxSelector, 0)
+	stateDB, err := statedb.NewLocalStateDB(stateDBPath, 128, syncStateDB, statedb.TypeTxSelector, 0)
 	require.NoError(t, err)
 	return stateDB
 }

db/statedb/statedb.go

@@ -3,9 +3,12 @@ package statedb
 import (
 	"errors"
 	"fmt"
+	"io/ioutil"
 	"math/big"
 	"os"
-	"strconv"
+	"path"
+	"sort"
+	"strings"
 
 	"github.com/hermeznetwork/hermez-node/common"
 	"github.com/hermeznetwork/hermez-node/log"
@@ -51,10 +54,10 @@ var (
 const (
 	// PathBatchNum defines the subpath of the Batch Checkpoint in the
 	// subpath of the StateDB
-	PathBatchNum = "/BatchNum"
+	PathBatchNum = "BatchNum"
 	// PathCurrent defines the subpath of the current Batch in the subpath
 	// of the StateDB
-	PathCurrent = "/current"
+	PathCurrent = "current"
 	// TypeSynchronizer defines a StateDB used by the Synchronizer, that
 	// generates the ExitTree when processing the txs
 	TypeSynchronizer = "synchronizer"
@@ -85,14 +88,16 @@ type StateDB struct {
 	// AccumulatedFees contains the accumulated fees for each token (Coord
 	// Idx) in the processed batch
 	AccumulatedFees map[common.Idx]*big.Int
+	keep            int
 }
 
 // NewStateDB creates a new StateDB, allowing to use an in-memory or in-disk
-// storage
-func NewStateDB(path string, typ TypeStateDB, nLevels int, chainID uint16) (*StateDB, error) {
+// storage.  Checkpoints older than the value defined by `keep` will be
+// deleted.
+func NewStateDB(pathDB string, keep int, typ TypeStateDB, nLevels int, chainID uint16) (*StateDB, error) {
 	var sto *pebble.PebbleStorage
 	var err error
-	sto, err = pebble.NewPebbleStorage(path+PathCurrent, false)
+	sto, err = pebble.NewPebbleStorage(path.Join(pathDB, PathCurrent), false)
 	if err != nil {
 		return nil, tracerr.Wrap(err)
 	}
@@ -109,11 +114,12 @@ func NewStateDB(path string, typ TypeStateDB, nLevels int, chainID uint16) (*Sta
 	}
 
 	sdb := &StateDB{
-		path:    path,
+		path:    pathDB,
 		db:      sto,
 		mt:      mt,
 		typ:     typ,
 		chainID: chainID,
+		keep:    keep,
 	}
 
 	// load currentBatch
@@ -170,10 +176,9 @@ func (s *StateDB) MakeCheckpoint() error {
 	s.currentBatch++
 	log.Debugw("Making StateDB checkpoint", "batch", s.currentBatch, "type", s.typ)
 
-	checkpointPath := s.path + PathBatchNum + strconv.Itoa(int(s.currentBatch))
+	checkpointPath := path.Join(s.path, fmt.Sprintf("%s%d", PathBatchNum, s.currentBatch))
 
-	err := s.setCurrentBatch()
-	if err != nil {
+	if err := s.setCurrentBatch(); err != nil {
 		return tracerr.Wrap(err)
 	}
 
@@ -188,8 +193,11 @@ func (s *StateDB) MakeCheckpoint() error {
 	}
 
 	// execute Checkpoint
-	err = s.db.Pebble().Checkpoint(checkpointPath)
-	if err != nil {
+	if err := s.db.Pebble().Checkpoint(checkpointPath); err != nil {
+		return tracerr.Wrap(err)
+	}
+	// delete old checkpoints
+	if err := s.deleteOldCheckpoints(); err != nil {
 		return tracerr.Wrap(err)
 	}
 
@@ -198,7 +206,7 @@ func (s *StateDB) MakeCheckpoint() error {
 
 // DeleteCheckpoint removes if exist the checkpoint of the given batchNum
 func (s *StateDB) DeleteCheckpoint(batchNum common.BatchNum) error {
-	checkpointPath := s.path + PathBatchNum + strconv.Itoa(int(batchNum))
+	checkpointPath := path.Join(s.path, fmt.Sprintf("%s%d", PathBatchNum, batchNum))
 
 	if _, err := os.Stat(checkpointPath); os.IsNotExist(err) {
 		return tracerr.Wrap(fmt.Errorf("Checkpoint with batchNum %d does not exist in DB", batchNum))
@@ -207,6 +215,55 @@ func (s *StateDB) DeleteCheckpoint(batchNum common.BatchNum) error {
 	return os.RemoveAll(checkpointPath)
 }
 
+// listCheckpoints returns the list of batchNums of the checkpoints, sorted.
+// If there's a gap between the list of checkpoints, an error is returned.
+func (s *StateDB) listCheckpoints() ([]int, error) {
+	files, err := ioutil.ReadDir(s.path)
+	if err != nil {
+		return nil, err
+	}
+	checkpoints := []int{}
+	var checkpoint int
+	pattern := fmt.Sprintf("%s%%d", PathBatchNum)
+	for _, file := range files {
+		fileName := file.Name()
+		if file.IsDir() && strings.HasPrefix(fileName, PathBatchNum) {
+			if _, err := fmt.Sscanf(fileName, pattern, &checkpoint); err != nil {
+				return nil, err
+			}
+			checkpoints = append(checkpoints, checkpoint)
+		}
+	}
+	sort.Ints(checkpoints)
+	if len(checkpoints) > 0 {
+		first := checkpoints[0]
+		for _, checkpoint := range checkpoints[1:] {
+			first++
+			if checkpoint != first {
+				return nil, fmt.Errorf("checkpoint gap at %v", checkpoint)
+			}
+		}
+	}
+	return checkpoints, nil
+}
+
+// deleteOldCheckpoints deletes old checkpoints when there are more than
+// `s.keep` checkpoints
+func (s *StateDB) deleteOldCheckpoints() error {
+	list, err := s.listCheckpoints()
+	if err != nil {
+		return err
+	}
+	if len(list) > s.keep {
+		for _, checkpoint := range list[:len(list)-s.keep] {
+			if err := s.DeleteCheckpoint(common.BatchNum(checkpoint)); err != nil {
+				return err
+			}
+		}
+	}
+	return nil
+}
+
 func pebbleMakeCheckpoint(source, dest string) error {
 	// Remove dest folder (if it exists) before doing the checkpoint
 	if _, err := os.Stat(dest); !os.IsNotExist(err) {
@@ -252,7 +309,7 @@ func (s *StateDB) Reset(batchNum common.BatchNum) error {
 // deleted when MakeCheckpoint overwrites them.  `closeCurrent` will close the
 // currently opened db before doing the reset.
 func (s *StateDB) reset(batchNum common.BatchNum, closeCurrent bool) error {
-	currentPath := s.path + PathCurrent
+	currentPath := path.Join(s.path, PathCurrent)
 
 	if closeCurrent {
 		if err := s.db.Pebble().Close(); err != nil {
@@ -264,6 +321,12 @@ func (s *StateDB) reset(batchNum common.BatchNum, closeCurrent bool) error {
 	if err != nil {
 		return tracerr.Wrap(err)
 	}
+	// remove all checkpoints > batchNum
+	for i := batchNum + 1; i <= s.currentBatch; i++ {
+		if err := s.DeleteCheckpoint(i); err != nil {
+			return err
+		}
+	}
 	if batchNum == 0 {
 		// if batchNum == 0, open the new fresh 'current'
 		sto, err := pebble.NewPebbleStorage(currentPath, false)
@@ -285,7 +348,7 @@ func (s *StateDB) reset(batchNum common.BatchNum, closeCurrent bool) error {
 		return nil
 	}
 
-	checkpointPath := s.path + PathBatchNum + strconv.Itoa(int(batchNum))
+	checkpointPath := path.Join(s.path, fmt.Sprintf("%s%d", PathBatchNum, batchNum))
 	// copy 'BatchNumX' to 'current'
 	err = pebbleMakeCheckpoint(checkpointPath, currentPath)
 	if err != nil {
@@ -521,9 +584,11 @@ type LocalStateDB struct {
 }
 
 // NewLocalStateDB returns a new LocalStateDB connected to the given
-// synchronizerDB
-func NewLocalStateDB(path string, synchronizerDB *StateDB, typ TypeStateDB, nLevels int) (*LocalStateDB, error) {
-	s, err := NewStateDB(path, typ, nLevels, synchronizerDB.chainID)
+// synchronizerDB.  Checkpoints older than the value defined by `keep` will be
+// deleted.
+func NewLocalStateDB(path string, keep int, synchronizerDB *StateDB, typ TypeStateDB,
+	nLevels int) (*LocalStateDB, error) {
+	s, err := NewStateDB(path, keep, typ, nLevels, synchronizerDB.chainID)
 	if err != nil {
 		return nil, tracerr.Wrap(err)
 	}
@@ -541,9 +606,10 @@ func (l *LocalStateDB) Reset(batchNum common.BatchNum, fromSynchronizer bool) er
 		return nil
 	}
 
-	synchronizerCheckpointPath := l.synchronizerStateDB.path + PathBatchNum + strconv.Itoa(int(batchNum))
-	checkpointPath := l.path + PathBatchNum + strconv.Itoa(int(batchNum))
-	currentPath := l.path + PathCurrent
+	synchronizerCheckpointPath := path.Join(l.synchronizerStateDB.path,
+		fmt.Sprintf("%s%d", PathBatchNum, batchNum))
+	checkpointPath := path.Join(l.path, fmt.Sprintf("%s%d", PathBatchNum, batchNum))
+	currentPath := path.Join(l.path, PathCurrent)
 
 	if fromSynchronizer {
 		// use checkpoint from SynchronizerStateDB

db/statedb/statedb_test.go

@@ -46,7 +46,7 @@ func TestNewStateDBIntermediateState(t *testing.T) {
 	defer assert.NoError(t, os.RemoveAll(dir))
 
 	chainID := uint16(0)
-	sdb, err := NewStateDB(dir, TypeTxSelector, 0, chainID)
+	sdb, err := NewStateDB(dir, 128, TypeTxSelector, 0, chainID)
 	assert.NoError(t, err)
 
 	// test values
@@ -68,7 +68,7 @@ func TestNewStateDBIntermediateState(t *testing.T) {
 
 	// call NewStateDB which should get the db at the last checkpoint state
 	// executing a Reset (discarding the last 'testkey0'&'testvalue0' data)
-	sdb, err = NewStateDB(dir, TypeTxSelector, 0, chainID)
+	sdb, err = NewStateDB(dir, 128, TypeTxSelector, 0, chainID)
 	assert.NoError(t, err)
 	v, err = sdb.db.Get(k0)
 	assert.NotNil(t, err)
@@ -110,7 +110,7 @@ func TestNewStateDBIntermediateState(t *testing.T) {
 
 	// call NewStateDB which should get the db at the last checkpoint state
 	// executing a Reset (discarding the last 'testkey1'&'testvalue1' data)
-	sdb, err = NewStateDB(dir, TypeTxSelector, 0, chainID)
+	sdb, err = NewStateDB(dir, 128, TypeTxSelector, 0, chainID)
 	assert.NoError(t, err)
 
 	v, err = sdb.db.Get(k0)
@@ -129,7 +129,7 @@ func TestStateDBWithoutMT(t *testing.T) {
 	defer assert.NoError(t, os.RemoveAll(dir))
 
 	chainID := uint16(0)
-	sdb, err := NewStateDB(dir, TypeTxSelector, 0, chainID)
+	sdb, err := NewStateDB(dir, 128, TypeTxSelector, 0, chainID)
 	assert.NoError(t, err)
 
 	// create test accounts
@@ -184,7 +184,7 @@ func TestStateDBWithMT(t *testing.T) {
 	defer assert.NoError(t, os.RemoveAll(dir))
 
 	chainID := uint16(0)
-	sdb, err := NewStateDB(dir, TypeSynchronizer, 32, chainID)
+	sdb, err := NewStateDB(dir, 128, TypeSynchronizer, 32, chainID)
 	assert.NoError(t, err)
 
 	// create test accounts
@@ -237,7 +237,7 @@ func TestCheckpoints(t *testing.T) {
 	defer assert.NoError(t, os.RemoveAll(dir))
 
 	chainID := uint16(0)
-	sdb, err := NewStateDB(dir, TypeSynchronizer, 32, chainID)
+	sdb, err := NewStateDB(dir, 128, TypeSynchronizer, 32, chainID)
 	assert.NoError(t, err)
 
 	// create test accounts
@@ -291,20 +291,20 @@ func TestCheckpoints(t *testing.T) {
 	assert.NoError(t, err)
 	assert.Equal(t, common.BatchNum(4), cb)
 
-	err = sdb.DeleteCheckpoint(common.BatchNum(9))
+	err = sdb.DeleteCheckpoint(common.BatchNum(1))
 	assert.NoError(t, err)
-	err = sdb.DeleteCheckpoint(common.BatchNum(10))
+	err = sdb.DeleteCheckpoint(common.BatchNum(2))
 	assert.NoError(t, err)
-	err = sdb.DeleteCheckpoint(common.BatchNum(9)) // does not exist, should return err
+	err = sdb.DeleteCheckpoint(common.BatchNum(1)) // does not exist, should return err
 	assert.NotNil(t, err)
-	err = sdb.DeleteCheckpoint(common.BatchNum(11)) // does not exist, should return err
+	err = sdb.DeleteCheckpoint(common.BatchNum(2)) // does not exist, should return err
 	assert.NotNil(t, err)
 
 	// Create a LocalStateDB from the initial StateDB
 	dirLocal, err := ioutil.TempDir("", "ldb")
 	require.NoError(t, err)
 	defer assert.NoError(t, os.RemoveAll(dirLocal))
-	ldb, err := NewLocalStateDB(dirLocal, sdb, TypeBatchBuilder, 32)
+	ldb, err := NewLocalStateDB(dirLocal, 128, sdb, TypeBatchBuilder, 32)
 	assert.NoError(t, err)
 
 	// get checkpoint 4 from sdb (StateDB) to ldb (LocalStateDB)
@@ -325,7 +325,7 @@ func TestCheckpoints(t *testing.T) {
 	dirLocal2, err := ioutil.TempDir("", "ldb2")
 	require.NoError(t, err)
 	defer assert.NoError(t, os.RemoveAll(dirLocal2))
-	ldb2, err := NewLocalStateDB(dirLocal2, sdb, TypeBatchBuilder, 32)
+	ldb2, err := NewLocalStateDB(dirLocal2, 128, sdb, TypeBatchBuilder, 32)
 	assert.NoError(t, err)
 
 	// get checkpoint 4 from sdb (StateDB) to ldb (LocalStateDB)
@@ -355,7 +355,7 @@ func TestStateDBGetAccounts(t *testing.T) {
 	require.NoError(t, err)
 
 	chainID := uint16(0)
-	sdb, err := NewStateDB(dir, TypeTxSelector, 0, chainID)
+	sdb, err := NewStateDB(dir, 128, TypeTxSelector, 0, chainID)
 	assert.NoError(t, err)
 
 	// create test accounts
@@ -403,7 +403,7 @@ func TestCheckAccountsTreeTestVectors(t *testing.T) {
 	defer assert.NoError(t, os.RemoveAll(dir))
 
 	chainID := uint16(0)
-	sdb, err := NewStateDB(dir, TypeSynchronizer, 32, chainID)
+	sdb, err := NewStateDB(dir, 128, TypeSynchronizer, 32, chainID)
 	require.NoError(t, err)
 
 	ay0 := new(big.Int).Sub(new(big.Int).Exp(big.NewInt(2), big.NewInt(253), nil), big.NewInt(1))
@@ -469,3 +469,56 @@ func TestCheckAccountsTreeTestVectors(t *testing.T) {
 	// root value generated by js version:
 	assert.Equal(t, "17298264051379321456969039521810887093935433569451713402227686942080129181291", sdb.mt.Root().BigInt().String())
 }
+
+func TestListCheckpoints(t *testing.T) {
+	dir, err := ioutil.TempDir("", "tmpdb")
+	require.NoError(t, err)
+	defer assert.NoError(t, os.RemoveAll(dir))
+
+	chainID := uint16(0)
+	sdb, err := NewStateDB(dir, 128, TypeSynchronizer, 32, chainID)
+	require.NoError(t, err)
+
+	numCheckpoints := 16
+	// do checkpoints
+	for i := 0; i < numCheckpoints; i++ {
+		err = sdb.MakeCheckpoint()
+		require.NoError(t, err)
+	}
+	list, err := sdb.listCheckpoints()
+	require.NoError(t, err)
+	assert.Equal(t, numCheckpoints, len(list))
+	assert.Equal(t, 1, list[0])
+	assert.Equal(t, numCheckpoints, list[len(list)-1])
+
+	numReset := 10
+	err = sdb.Reset(common.BatchNum(numReset))
+	require.NoError(t, err)
+	list, err = sdb.listCheckpoints()
+	require.NoError(t, err)
+	assert.Equal(t, numReset, len(list))
+	assert.Equal(t, 1, list[0])
+	assert.Equal(t, numReset, list[len(list)-1])
+}
+
+func TestDeleteOldCheckpoints(t *testing.T) {
+	dir, err := ioutil.TempDir("", "tmpdb")
+	require.NoError(t, err)
+	defer assert.NoError(t, os.RemoveAll(dir))
+
+	chainID := uint16(0)
+	keep := 16
+	sdb, err := NewStateDB(dir, keep, TypeSynchronizer, 32, chainID)
+	require.NoError(t, err)
+
+	numCheckpoints := 32
+	// do checkpoints and check that we never have more than `keep`
+	// checkpoints
+	for i := 0; i < numCheckpoints; i++ {
+		err = sdb.MakeCheckpoint()
+		require.NoError(t, err)
+		checkpoints, err := sdb.listCheckpoints()
+		require.NoError(t, err)
+		assert.LessOrEqual(t, len(checkpoints), keep)
+	}
+}

db/statedb/txprocessors_test.go

@@ -29,7 +29,7 @@ func TestComputeEffectiveAmounts(t *testing.T) {
 	defer assert.NoError(t, os.RemoveAll(dir))
 
 	chainID := uint16(0)
-	sdb, err := NewStateDB(dir, TypeSynchronizer, 32, chainID)
+	sdb, err := NewStateDB(dir, 128, TypeSynchronizer, 32, chainID)
 	assert.NoError(t, err)
 
 	set := `
@@ -203,7 +203,7 @@ func TestProcessTxsBalances(t *testing.T) {
 	defer assert.NoError(t, os.RemoveAll(dir))
 
 	chainID := uint16(0)
-	sdb, err := NewStateDB(dir, TypeSynchronizer, 32, chainID)
+	sdb, err := NewStateDB(dir, 128, TypeSynchronizer, 32, chainID)
 	assert.NoError(t, err)
 
 	// generate test transactions from test.SetBlockchain0 code
@@ -336,7 +336,7 @@ func TestProcessTxsSynchronizer(t *testing.T) {
 	defer assert.NoError(t, os.RemoveAll(dir))
 
 	chainID := uint16(0)
-	sdb, err := NewStateDB(dir, TypeSynchronizer, 32, chainID)
+	sdb, err := NewStateDB(dir, 128, TypeSynchronizer, 32, chainID)
 	assert.NoError(t, err)
 
 	// generate test transactions from test.SetBlockchain0 code
@@ -465,7 +465,7 @@ func TestProcessTxsBatchBuilder(t *testing.T) {
 	defer assert.NoError(t, os.RemoveAll(dir))
 
 	chainID := uint16(0)
-	sdb, err := NewStateDB(dir, TypeBatchBuilder, 32, chainID)
+	sdb, err := NewStateDB(dir, 128, TypeBatchBuilder, 32, chainID)
 	assert.NoError(t, err)
 
 	// generate test transactions from test.SetBlockchain0 code
@@ -554,7 +554,7 @@ func TestProcessTxsRootTestVectors(t *testing.T) {
 	defer assert.NoError(t, os.RemoveAll(dir))
 
 	chainID := uint16(0)
-	sdb, err := NewStateDB(dir, TypeBatchBuilder, 32, chainID)
+	sdb, err := NewStateDB(dir, 128, TypeBatchBuilder, 32, chainID)
 	assert.NoError(t, err)
 
 	// same values than in the js test
@@ -603,7 +603,7 @@ func TestCreateAccountDepositMaxValue(t *testing.T) {
 
 	nLevels := 16
 	chainID := uint16(0)
-	sdb, err := NewStateDB(dir, TypeBatchBuilder, nLevels, chainID)
+	sdb, err := NewStateDB(dir, 128, TypeBatchBuilder, nLevels, chainID)
 	assert.NoError(t, err)
 
 	users := generateJsUsers(t)

db/statedb/utils_test.go

@@ -21,7 +21,7 @@ func TestGetIdx(t *testing.T) {
 	defer assert.NoError(t, os.RemoveAll(dir))
 
 	chainID := uint16(0)
-	sdb, err := NewStateDB(dir, TypeTxSelector, 0, chainID)
+	sdb, err := NewStateDB(dir, 128, TypeTxSelector, 0, chainID)
 	assert.NoError(t, err)
 
 	var sk babyjub.PrivateKey

db/statedb/zkinputsgen_test.go

@@ -79,7 +79,7 @@ func TestZKInputsHashTestVector0(t *testing.T) {
 	defer assert.Nil(t, os.RemoveAll(dir))
 
 	chainID := uint16(0)
-	sdb, err := NewStateDB(dir, TypeBatchBuilder, 32, chainID)
+	sdb, err := NewStateDB(dir, 128, TypeBatchBuilder, 32, chainID)
 	assert.Nil(t, err)
 
 	// same values than in the js test
@@ -154,7 +154,7 @@ func TestZKInputsHashTestVector1(t *testing.T) {
 	defer assert.Nil(t, os.RemoveAll(dir))
 
 	chainID := uint16(0)
-	sdb, err := NewStateDB(dir, TypeBatchBuilder, 32, chainID)
+	sdb, err := NewStateDB(dir, 128, TypeBatchBuilder, 32, chainID)
 	assert.Nil(t, err)
 
 	// same values than in the js test
@@ -254,7 +254,7 @@ func TestZKInputsEmpty(t *testing.T) {
 	nLevels := 16
 
 	chainID := uint16(0)
-	sdb, err := NewStateDB(dir, TypeBatchBuilder, nLevels, chainID)
+	sdb, err := NewStateDB(dir, 128, TypeBatchBuilder, nLevels, chainID)
 	assert.Nil(t, err)
 
 	ptc := ProcessTxsConfig{
@@ -403,7 +403,7 @@ func TestZKInputs0(t *testing.T) {
 
 	nLevels := 16
 	chainID := uint16(0)
-	sdb, err := NewStateDB(dir, TypeBatchBuilder, nLevels, chainID)
+	sdb, err := NewStateDB(dir, 128, TypeBatchBuilder, nLevels, chainID)
 	assert.Nil(t, err)
 
 	// same values than in the js test
@@ -491,7 +491,7 @@ func TestZKInputs1(t *testing.T) {
 
 	nLevels := 16
 	chainID := uint16(0)
-	sdb, err := NewStateDB(dir, TypeBatchBuilder, nLevels, chainID)
+	sdb, err := NewStateDB(dir, 128, TypeBatchBuilder, nLevels, chainID)
 	assert.Nil(t, err)
 
 	// same values than in the js test
@@ -598,7 +598,7 @@ func TestZKInputs2(t *testing.T) {
 
 	nLevels := 16
 	chainID := uint16(0)
-	sdb, err := NewStateDB(dir, TypeBatchBuilder, nLevels, chainID)
+	sdb, err := NewStateDB(dir, 128, TypeBatchBuilder, nLevels, chainID)
 	assert.Nil(t, err)
 
 	// same values than in the js test
@@ -742,7 +742,7 @@ func TestZKInputs3(t *testing.T) {
 
 	nLevels := 16
 	chainID := uint16(0)
-	sdb, err := NewStateDB(dir, TypeBatchBuilder, nLevels, chainID)
+	sdb, err := NewStateDB(dir, 128, TypeBatchBuilder, nLevels, chainID)
 	assert.Nil(t, err)
 
 	// same values than in the js test
@@ -886,7 +886,7 @@ func TestZKInputs4(t *testing.T) {
 
 	nLevels := 16
 	chainID := uint16(0)
-	sdb, err := NewStateDB(dir, TypeBatchBuilder, nLevels, chainID)
+	sdb, err := NewStateDB(dir, 128, TypeBatchBuilder, nLevels, chainID)
 	assert.Nil(t, err)
 
 	// same values than in the js test
@@ -1040,7 +1040,7 @@ func TestZKInputs5(t *testing.T) {
 
 	nLevels := 16
 	chainID := uint16(0)
-	sdb, err := NewStateDB(dir, TypeBatchBuilder, nLevels, chainID)
+	sdb, err := NewStateDB(dir, 128, TypeBatchBuilder, nLevels, chainID)
 	assert.Nil(t, err)
 
 	// same values than in the js test
@@ -1164,7 +1164,7 @@ func TestZKInputs6(t *testing.T) {
 
 	nLevels := 16
 	chainID := uint16(0)
-	sdb, err := NewStateDB(dir, TypeBatchBuilder, nLevels, chainID)
+	sdb, err := NewStateDB(dir, 128, TypeBatchBuilder, nLevels, chainID)
 	assert.Nil(t, err)
 
 	// Coordinator Idx where to send the fees

node/node.go

@@ -130,7 +130,13 @@ func NewNode(mode Mode, cfg *config.Node) (*Node, error) {
 	}
 	chainIDU16 := uint16(chainIDU64)
 
-	stateDB, err := statedb.NewStateDB(cfg.StateDB.Path, statedb.TypeSynchronizer, 32, chainIDU16)
+	const safeStateDBKeep = 128
+	if cfg.StateDB.Keep < safeStateDBKeep {
+		return nil, tracerr.Wrap(fmt.Errorf("cfg.StateDB.Keep = %v < %v, which is unsafe",
+			cfg.StateDB.Keep, safeStateDBKeep))
+	}
+	stateDB, err := statedb.NewStateDB(cfg.StateDB.Path, cfg.StateDB.Keep,
+		statedb.TypeSynchronizer, 32, chainIDU16)
 	if err != nil {
 		return nil, tracerr.Wrap(err)
 	}

synchronizer/synchronizer_test.go

@@ -290,7 +290,7 @@ func newTestModules(t *testing.T) (*statedb.StateDB, *historydb.HistoryDB) {
 	require.NoError(t, err)
 	deleteme = append(deleteme, dir)
 
-	stateDB, err := statedb.NewStateDB(dir, statedb.TypeSynchronizer, 32, chainID)
+	stateDB, err := statedb.NewStateDB(dir, 128, statedb.TypeSynchronizer, 32, chainID)
 	require.NoError(t, err)
 
 	// Init History DB

test/debugapi/debugapi_test.go

@@ -45,7 +45,7 @@ func TestDebugAPI(t *testing.T) {
 	require.Nil(t, err)
 
 	chainID := uint16(0)
-	sdb, err := statedb.NewStateDB(dir, statedb.TypeSynchronizer, 32, chainID)
+	sdb, err := statedb.NewStateDB(dir, 128, statedb.TypeSynchronizer, 32, chainID)
 	require.Nil(t, err)
 	err = sdb.MakeCheckpoint() // Make a checkpoint to increment the batchNum
 	require.Nil(t, err)

txselector/txselector.go

@@ -72,7 +72,7 @@ type TxSelector struct {
 // NewTxSelector returns a *TxSelector
 func NewTxSelector(coordAccount *CoordAccount, dbpath string,
 	synchronizerStateDB *statedb.StateDB, l2 *l2db.L2DB) (*TxSelector, error) {
-	localAccountsDB, err := statedb.NewLocalStateDB(dbpath,
+	localAccountsDB, err := statedb.NewLocalStateDB(dbpath, 128,
 		synchronizerStateDB, statedb.TypeTxSelector, 0) // without merkletree
 	if err != nil {
 		return nil, tracerr.Wrap(err)

txselector/txselector_test.go

@@ -29,7 +29,7 @@ func initTest(t *testing.T, chainID uint16, testSet string) *TxSelector {
 	dir, err := ioutil.TempDir("", "tmpdb")
 	require.NoError(t, err)
 	defer assert.NoError(t, os.RemoveAll(dir))
-	sdb, err := statedb.NewStateDB(dir, statedb.TypeTxSelector, 0, chainID)
+	sdb, err := statedb.NewStateDB(dir, 128, statedb.TypeTxSelector, 0, chainID)
 	require.NoError(t, err)
 
 	txselDir, err := ioutil.TempDir("", "tmpTxSelDB")