Add minPriceUSD in L2DB, check maxTxs atomically

- Add config parameter `Coordinator.L2DB.MinPriceUSD` which allows rejecting
  txs to the pool that have a fee lower than the minimum.
- In pool tx insertion, checking the number of pending txs atomically with the
  insertion to avoid data races leading to more than MaxTxs pending txs in the
  pool.

api/api_test.go

@@ -221,7 +221,7 @@ func TestMain(m *testing.M) {
 		panic(err)
 	}
 	// L2DB
-	l2DB := l2db.NewL2DB(database, 10, 1000, 24*time.Hour, apiConnCon)
+	l2DB := l2db.NewL2DB(database, 10, 1000, 0.0, 24*time.Hour, apiConnCon)
 	test.WipeDB(l2DB.DB()) // this will clean HistoryDB and L2DB
 	// Config (smart contract constants)
 	chainID := uint16(0)
@@ -585,7 +585,7 @@ func TestTimeout(t *testing.T) {
 	hdbTO := historydb.NewHistoryDB(databaseTO, apiConnConTO)
 	require.NoError(t, err)
 	// L2DB
-	l2DBTO := l2db.NewL2DB(databaseTO, 10, 1000, 24*time.Hour, apiConnConTO)
+	l2DBTO := l2db.NewL2DB(databaseTO, 10, 1000, 0.0, 24*time.Hour, apiConnConTO)
 
 	// API
 	apiGinTO := gin.Default()

api/handlers.go

@@ -10,6 +10,7 @@ import (
 	"github.com/hermeznetwork/hermez-node/log"
 	"github.com/hermeznetwork/tracerr"
 	"github.com/lib/pq"
+	"github.com/russross/meddler"
 )
 
 const (
@@ -46,24 +47,33 @@ var (
 func retSQLErr(err error, c *gin.Context) {
 	log.Warnw("HTTP API SQL request error", "err", err)
 	errMsg := tracerr.Unwrap(err).Error()
+	retDupKey := func(errCode pq.ErrorCode) {
+		// https://www.postgresql.org/docs/current/errcodes-appendix.html
+		if errCode == "23505" {
+			c.JSON(http.StatusInternalServerError, errorMsg{
+				Message: errDuplicatedKey,
+			})
+		} else {
+			c.JSON(http.StatusInternalServerError, errorMsg{
+				Message: errMsg,
+			})
+		}
+	}
 	if errMsg == errCtxTimeout {
 		c.JSON(http.StatusServiceUnavailable, errorMsg{
 			Message: errSQLTimeout,
 		})
 	} else if sqlErr, ok := tracerr.Unwrap(err).(*pq.Error); ok {
-		// https://www.postgresql.org/docs/current/errcodes-appendix.html
+		retDupKey(sqlErr.Code)
-		if sqlErr.Code == "23505" {
+	} else if sqlErr, ok := meddler.DriverErr(tracerr.Unwrap(err)); ok {
-			c.JSON(http.StatusInternalServerError, errorMsg{
+		retDupKey(sqlErr.(*pq.Error).Code)
-				Message: errDuplicatedKey,
-			})
-		}
 	} else if tracerr.Unwrap(err) == sql.ErrNoRows {
 		c.JSON(http.StatusNotFound, errorMsg{
-			Message: err.Error(),
+			Message: errMsg,
 		})
 	} else {
 		c.JSON(http.StatusInternalServerError, errorMsg{
-			Message: err.Error(),
+			Message: errMsg,
 		})
 	}
 }

api/txspool.go

@@ -2,6 +2,7 @@ package api
 
 import (
 	"errors"
+	"fmt"
 	"math/big"
 	"net/http"
 
@@ -27,6 +28,7 @@ func (a *API) postPoolTx(c *gin.Context) {
 		retBadReq(err, c)
 		return
 	}
+	writeTx.ClientIP = c.ClientIP()
 	// Insert to DB
 	if err := a.l2.AddTxAPI(writeTx); err != nil {
 		retSQLErr(err, c)
@@ -179,6 +181,11 @@ func (a *API) verifyPoolL2TxWrite(txw *l2db.PoolL2TxWrite) error {
 	if err != nil {
 		return tracerr.Wrap(err)
 	}
+	// Validate TokenID
+	if poolTx.TokenID != account.TokenID {
+		return tracerr.Wrap(fmt.Errorf("tx.TokenID (%v) != account.TokenID (%v)",
+			poolTx.TokenID, account.TokenID))
+	}
 	// Check signature
 	if !poolTx.VerifySignature(a.chainID, account.BJJ) {
 		return tracerr.Wrap(errors.New("wrong signature"))

api/txspool_test.go

@@ -10,6 +10,7 @@ import (
 	"github.com/hermeznetwork/hermez-node/db/historydb"
 	"github.com/iden3/go-iden3-crypto/babyjub"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 // testPoolTxReceive is a struct to be used to assert the response
@@ -170,9 +171,9 @@ func TestPoolTxs(t *testing.T) {
 	fetchedTxID := common.TxID{}
 	for _, tx := range tc.poolTxsToSend {
 		jsonTxBytes, err := json.Marshal(tx)
-		assert.NoError(t, err)
+		require.NoError(t, err)
 		jsonTxReader := bytes.NewReader(jsonTxBytes)
-		assert.NoError(
+		require.NoError(
 			t, doGoodReq(
 				"POST",
 				endpoint,
@@ -187,42 +188,42 @@ func TestPoolTxs(t *testing.T) {
 	badTx.Amount = "99950000000000000"
 	badTx.Fee = 255
 	jsonTxBytes, err := json.Marshal(badTx)
-	assert.NoError(t, err)
+	require.NoError(t, err)
 	jsonTxReader := bytes.NewReader(jsonTxBytes)
 	err = doBadReq("POST", endpoint, jsonTxReader, 400)
-	assert.NoError(t, err)
+	require.NoError(t, err)
 	// Wrong signature
 	badTx = tc.poolTxsToSend[0]
 	badTx.FromIdx = "hez:foo:1000"
 	jsonTxBytes, err = json.Marshal(badTx)
-	assert.NoError(t, err)
+	require.NoError(t, err)
 	jsonTxReader = bytes.NewReader(jsonTxBytes)
 	err = doBadReq("POST", endpoint, jsonTxReader, 400)
-	assert.NoError(t, err)
+	require.NoError(t, err)
 	// Wrong to
 	badTx = tc.poolTxsToSend[0]
 	ethAddr := "hez:0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF"
 	badTx.ToEthAddr = &ethAddr
 	badTx.ToIdx = nil
 	jsonTxBytes, err = json.Marshal(badTx)
-	assert.NoError(t, err)
+	require.NoError(t, err)
 	jsonTxReader = bytes.NewReader(jsonTxBytes)
 	err = doBadReq("POST", endpoint, jsonTxReader, 400)
-	assert.NoError(t, err)
+	require.NoError(t, err)
 	// Wrong rq
 	badTx = tc.poolTxsToSend[0]
 	rqFromIdx := "hez:foo:30"
 	badTx.RqFromIdx = &rqFromIdx
 	jsonTxBytes, err = json.Marshal(badTx)
-	assert.NoError(t, err)
+	require.NoError(t, err)
 	jsonTxReader = bytes.NewReader(jsonTxBytes)
 	err = doBadReq("POST", endpoint, jsonTxReader, 400)
-	assert.NoError(t, err)
+	require.NoError(t, err)
 	// GET
 	endpoint += "/"
 	for _, tx := range tc.poolTxsToReceive {
 		fetchedTx := testPoolTxReceive{}
-		assert.NoError(
+		require.NoError(
 			t, doGoodReq(
 				"GET",
 				endpoint+tx.TxID.String(),
@@ -233,10 +234,10 @@ func TestPoolTxs(t *testing.T) {
 	}
 	// 400, due invalid TxID
 	err = doBadReq("GET", endpoint+"0xG2241b6f2b1dd772dba391f4a1a3407c7c21f598d86e2585a14e616fb4a255f823", nil, 400)
-	assert.NoError(t, err)
+	require.NoError(t, err)
 	// 404, due inexistent TxID in DB
 	err = doBadReq("GET", endpoint+"0x02241b6f2b1dd772dba391f4a1a3407c7c21f598d86e2585a14e616fb4a255f823", nil, 404)
-	assert.NoError(t, err)
+	require.NoError(t, err)
 }
 
 func assertPoolTx(t *testing.T, expected, actual testPoolTxReceive) {

cli/node/.gitignore

@@ -1,2 +1,3 @@
 cfg.example.secret.toml
 cfg.toml
+node

cli/node/cfg.buidler.toml

@@ -32,6 +32,7 @@ URL = "http://localhost:8545"
 [Synchronizer]
 SyncLoopInterval = "1s"
 StatsRefreshPeriod = "1s"
+StoreAccountUpdates = true
 
 [SmartContracts]
 Rollup   = "0x8EEaea23686c319133a7cC110b840d1591d9AeE0"
@@ -55,6 +56,7 @@ ForgeRetryInterval = "500ms"
 SyncRetryInterval = "1s"
 ForgeDelay = "10s"
 ForgeNoTxsDelay = "0s"
+PurgeByExtDelInterval = "1m"
 
 [Coordinator.FeeAccount]
 Address = "0x56232B1c5B10038125Bc7345664B4AFD745bcF8E"
@@ -65,6 +67,7 @@ BJJ = "0x1b176232f78ba0d388ecc5f4896eca2d3b3d4f272092469f559247297f5c0c13"
 [Coordinator.L2DB]
 SafetyPeriod = 10
 MaxTxs       = 512
+MinFeeUSD    = 0.0
 TTL          = "24h"
 PurgeBatchDelay = 10
 InvalidateBatchDelay = 20

cli/node/main.go

@@ -173,6 +173,7 @@ func cmdDiscard(c *cli.Context) error {
 		db,
 		cfg.Coordinator.L2DB.SafetyPeriod,
 		cfg.Coordinator.L2DB.MaxTxs,
+		cfg.Coordinator.L2DB.MinFeeUSD,
 		cfg.Coordinator.L2DB.TTL.Duration,
 		nil,
 	)

common/account.go

@@ -263,3 +263,13 @@ type IdxNonce struct {
 	Idx   Idx   `db:"idx"`
 	Nonce Nonce `db:"nonce"`
 }
+
+// AccountUpdate represents an account balance and/or nonce update after a
+// processed batch
+type AccountUpdate struct {
+	EthBlockNum int64    `meddler:"eth_block_num"`
+	BatchNum    BatchNum `meddler:"batch_num"`
+	Idx         Idx      `meddler:"idx"`
+	Nonce       Nonce    `meddler:"nonce"`
+	Balance     *big.Int `meddler:"balance,bigint"`
+}

common/batch.go

@@ -77,6 +77,7 @@ type BatchData struct {
 	L1CoordinatorTxs []L1Tx
 	L2Txs            []L2Tx
 	CreatedAccounts  []Account
+	UpdatedAccounts  []AccountUpdate
 	ExitTree         []ExitInfo
 	Batch            Batch
 }

common/utils.go

@@ -62,3 +62,17 @@ func RmEndingZeroes(siblings []*merkletree.Hash) []*merkletree.Hash {
 	}
 	return siblings[:pos]
 }
+
+// TokensToUSD is a helper function to calculate the USD value of a certain
+// amount of tokens considering the normalized token price (which is the price
+// commonly reported by exhanges)
+func TokensToUSD(amount *big.Int, decimals uint64, valueUSD float64) float64 {
+	amountF := new(big.Float).SetInt(amount)
+	// Divide by 10^decimals to normalize the amount
+	baseF := new(big.Float).SetInt(new(big.Int).Exp(
+		big.NewInt(10), big.NewInt(int64(decimals)), nil)) //nolint:gomnd
+	amountF.Mul(amountF, big.NewFloat(valueUSD))
+	amountF.Quo(amountF, baseF)
+	amountUSD, _ := amountF.Float64()
+	return amountUSD
+}

config/config.go

@@ -91,6 +91,10 @@ type Coordinator struct {
 	// SyncRetryInterval is the waiting interval between calls to the main
 	// handler of a synced block after an error
 	SyncRetryInterval Duration `validate:"required"`
+	// PurgeByExtDelInterval is the waiting interval between calls
+	// to the PurgeByExternalDelete function of the l2db which deletes
+	// pending txs externally marked by the column `external_delete`
+	PurgeByExtDelInterval Duration `validate:"required"`
 	// L2DB is the DB that holds the pool of L2Txs
 	L2DB struct {
 		// SafetyPeriod is the number of batches after which
@@ -101,6 +105,10 @@ type Coordinator struct {
 		// reached, inserts to the pool will be denied until some of
 		// the pending txs are forged.
 		MaxTxs uint32 `validate:"required"`
+		// MinFeeUSD is the minimum fee in USD that a tx must pay in
+		// order to be accepted into the pool.  Txs with lower than
+		// minimum fee will be rejected at the API level.
+		MinFeeUSD float64
 		// TTL is the Time To Live for L2Txs in the pool.  Once MaxTxs
 		// L2Txs is reached, L2Txs older than TTL will be deleted.
 		TTL Duration `validate:"required"`
@@ -232,6 +240,11 @@ type Node struct {
 		// `Eth.LastBatch`).  This value only affects the reported % of
 		// synchronization of blocks and batches, nothing else.
 		StatsRefreshPeriod Duration `validate:"required"`
+		// StoreAccountUpdates when set to true makes the synchronizer
+		// store every account update in the account_update SQL table.
+		// This allows querying nonces and balances from the HistoryDB
+		// via SQL.
+		StoreAccountUpdates bool
 	} `validate:"required"`
 	SmartContracts struct {
 		// Rollup is the address of the Hermez.sol smart contract

coordinator/coordinator.go

@@ -85,6 +85,10 @@ type Config struct {
 	// SyncRetryInterval is the waiting interval between calls to the main
 	// handler of a synced block after an error
 	SyncRetryInterval time.Duration
+	// PurgeByExtDelInterval is the waiting interval between calls
+	// to the PurgeByExternalDelete function of the l2db which deletes
+	// pending txs externally marked by the column `external_delete`
+	PurgeByExtDelInterval time.Duration
 	// EthClientAttemptsDelay is delay between attempts do do an eth client
 	// RPC call
 	EthClientAttemptsDelay time.Duration
@@ -153,6 +157,15 @@ type Coordinator struct {
 	wg     sync.WaitGroup
 	cancel context.CancelFunc
 
+	// mutexL2DBUpdateDelete protects updates to the L2DB so that
+	// these two processes always happen exclusively:
+	// - Pipeline taking pending txs, running through the TxProcessor and
+	//   marking selected txs as forging
+	// - Coordinator deleting pending txs that have been marked with
+	//   `external_delete`.
+	// Without this mutex, the coordinator could delete a pending txs that
+	// has just been selected by the TxProcessor in the pipeline.
+	mutexL2DBUpdateDelete sync.Mutex
 	pipeline              *Pipeline
 	lastNonFailedBatchNum common.BatchNum
 
@@ -248,7 +261,8 @@ func (c *Coordinator) BatchBuilder() *batchbuilder.BatchBuilder {
 func (c *Coordinator) newPipeline(ctx context.Context) (*Pipeline, error) {
 	c.pipelineNum++
 	return NewPipeline(ctx, c.cfg, c.pipelineNum, c.historyDB, c.l2DB, c.txSelector,
-		c.batchBuilder, c.purger, c, c.txManager, c.provers, &c.consts)
+		c.batchBuilder, &c.mutexL2DBUpdateDelete, c.purger, c, c.txManager,
+		c.provers, &c.consts)
 }
 
 // MsgSyncBlock indicates an update to the Synchronizer stats
@@ -527,6 +541,24 @@ func (c *Coordinator) Start() {
 			}
 		}
 	}()
+
+	c.wg.Add(1)
+	go func() {
+		for {
+			select {
+			case <-c.ctx.Done():
+				log.Info("Coordinator L2DB.PurgeByExternalDelete loop done")
+				c.wg.Done()
+				return
+			case <-time.After(c.cfg.PurgeByExtDelInterval):
+				c.mutexL2DBUpdateDelete.Lock()
+				if err := c.l2DB.PurgeByExternalDelete(); err != nil {
+					log.Errorw("L2DB.PurgeByExternalDelete", "err", err)
+				}
+				c.mutexL2DBUpdateDelete.Unlock()
+			}
+		}
+	}()
 }
 
 const stopCtxTimeout = 200 * time.Millisecond

coordinator/coordinator_test.go

@@ -105,7 +105,7 @@ func newTestModules(t *testing.T) modules {
 	db, err := dbUtils.InitSQLDB(5432, "localhost", "hermez", pass, "hermez")
 	require.NoError(t, err)
 	test.WipeDB(db)
-	l2DB := l2db.NewL2DB(db, 10, 100, 24*time.Hour, nil)
+	l2DB := l2db.NewL2DB(db, 10, 100, 0.0, 24*time.Hour, nil)
 	historyDB := historydb.NewHistoryDB(db, nil)
 
 	txSelDBPath, err = ioutil.TempDir("", "tmpTxSelDB")

coordinator/pipeline.go

@@ -53,6 +53,7 @@ type Pipeline struct {
 	l2DB                  *l2db.L2DB
 	txSelector            *txselector.TxSelector
 	batchBuilder          *batchbuilder.BatchBuilder
+	mutexL2DBUpdateDelete *sync.Mutex
 	purger                *Purger
 
 	stats       synchronizer.Stats
@@ -84,6 +85,7 @@ func NewPipeline(ctx context.Context,
 	l2DB *l2db.L2DB,
 	txSelector *txselector.TxSelector,
 	batchBuilder *batchbuilder.BatchBuilder,
+	mutexL2DBUpdateDelete *sync.Mutex,
 	purger *Purger,
 	coord *Coordinator,
 	txManager *TxManager,
@@ -112,6 +114,7 @@ func NewPipeline(ctx context.Context,
 		batchBuilder:          batchBuilder,
 		provers:               provers,
 		proversPool:           proversPool,
+		mutexL2DBUpdateDelete: mutexL2DBUpdateDelete,
 		purger:                purger,
 		coord:                 coord,
 		txManager:             txManager,
@@ -199,7 +202,9 @@ func (p *Pipeline) syncSCVars(vars synchronizer.SCVariablesPtr) {
 // and then waits for an available proof server and sends the zkInputs to it so
 // that the proof computation begins.
 func (p *Pipeline) handleForgeBatch(ctx context.Context, batchNum common.BatchNum) (*BatchInfo, error) {
+	p.mutexL2DBUpdateDelete.Lock()
 	batchInfo, err := p.forgeBatch(batchNum)
+	p.mutexL2DBUpdateDelete.Unlock()
 	if ctx.Err() != nil {
 		return nil, ctx.Err()
 	} else if err != nil {

coordinator/purger_test.go

@@ -21,7 +21,7 @@ func newL2DB(t *testing.T) *l2db.L2DB {
 	db, err := dbUtils.InitSQLDB(5432, "localhost", "hermez", pass, "hermez")
 	require.NoError(t, err)
 	test.WipeDB(db)
-	return l2db.NewL2DB(db, 10, 100, 24*time.Hour, nil)
+	return l2db.NewL2DB(db, 10, 100, 0.0, 24*time.Hour, nil)
 }
 
 func newStateDB(t *testing.T) *statedb.LocalStateDB {

coordinator/txmanager.go

@@ -2,9 +2,9 @@ package coordinator
 
 import (
 	"context"
-	"errors"
 	"fmt"
 	"math/big"
+	"strings"
 	"time"
 
 	"github.com/ethereum/go-ethereum"
@@ -206,22 +206,27 @@ func (t *TxManager) sendRollupForgeBatch(ctx context.Context, batchInfo *BatchIn
 		}
 		// RollupForgeBatch() calls ethclient.SendTransaction()
 		ethTx, err = t.ethClient.RollupForgeBatch(batchInfo.ForgeBatchArgs, auth)
-		if errors.Is(err, core.ErrNonceTooLow) {
+		// We check the errors via strings because we match the
+		// definition of the error from geth, with the string returned
+		// via RPC obtained by the client.
+		if err == nil {
+			break
+		} else if strings.Contains(err.Error(), core.ErrNonceTooLow.Error()) {
 			log.Warnw("TxManager ethClient.RollupForgeBatch incrementing nonce",
 				"err", err, "nonce", auth.Nonce, "batchNum", batchInfo.BatchNum)
 			auth.Nonce.Add(auth.Nonce, big.NewInt(1))
 			attempt--
-		} else if errors.Is(err, core.ErrNonceTooHigh) {
+		} else if strings.Contains(err.Error(), core.ErrNonceTooHigh.Error()) {
 			log.Warnw("TxManager ethClient.RollupForgeBatch decrementing nonce",
 				"err", err, "nonce", auth.Nonce, "batchNum", batchInfo.BatchNum)
 			auth.Nonce.Sub(auth.Nonce, big.NewInt(1))
 			attempt--
-		} else if errors.Is(err, core.ErrUnderpriced) {
+		} else if strings.Contains(err.Error(), core.ErrReplaceUnderpriced.Error()) {
 			log.Warnw("TxManager ethClient.RollupForgeBatch incrementing gasPrice",
 				"err", err, "gasPrice", auth.GasPrice, "batchNum", batchInfo.BatchNum)
 			auth.GasPrice = addPerc(auth.GasPrice, 10)
 			attempt--
-		} else if errors.Is(err, core.ErrReplaceUnderpriced) {
+		} else if strings.Contains(err.Error(), core.ErrUnderpriced.Error()) {
 			log.Warnw("TxManager ethClient.RollupForgeBatch incrementing gasPrice",
 				"err", err, "gasPrice", auth.GasPrice, "batchNum", batchInfo.BatchNum)
 			auth.GasPrice = addPerc(auth.GasPrice, 10)
@@ -230,8 +235,6 @@ func (t *TxManager) sendRollupForgeBatch(ctx context.Context, batchInfo *BatchIn
 			log.Errorw("TxManager ethClient.RollupForgeBatch",
 				"attempt", attempt, "err", err, "block", t.stats.Eth.LastBlock.Num+1,
 				"batchNum", batchInfo.BatchNum)
-		} else {
-			break
 		}
 		select {
 		case <-ctx.Done():

db/historydb/historydb.go

@@ -61,7 +61,7 @@ func (hdb *HistoryDB) addBlocks(d meddler.DB, blocks []common.Block) error {
 			timestamp,
 			hash
 		) VALUES %s;`,
-		blocks[:],
+		blocks,
 	))
 }
 
@@ -273,7 +273,7 @@ func (hdb *HistoryDB) addBids(d meddler.DB, bids []common.Bid) error {
 	return tracerr.Wrap(db.BulkInsert(
 		d,
 		"INSERT INTO bid (slot_num, bid_value, eth_block_num, bidder_addr) VALUES %s;",
-		bids[:],
+		bids,
 	))
 }
 
@@ -324,7 +324,7 @@ func (hdb *HistoryDB) addCoordinators(d meddler.DB, coordinators []common.Coordi
 	return tracerr.Wrap(db.BulkInsert(
 		d,
 		"INSERT INTO coordinator (bidder_addr, forger_addr, eth_block_num, url) VALUES %s;",
-		coordinators[:],
+		coordinators,
 	))
 }
 
@@ -340,7 +340,7 @@ func (hdb *HistoryDB) addExitTree(d meddler.DB, exitTree []common.ExitInfo) erro
 		d,
 		"INSERT INTO exit_tree (batch_num, account_idx, merkle_proof, balance, "+
 			"instant_withdrawn, delayed_withdraw_request, delayed_withdrawn) VALUES %s;",
-		exitTree[:],
+		exitTree,
 	))
 }
 
@@ -443,11 +443,12 @@ func (hdb *HistoryDB) addTokens(d meddler.DB, tokens []common.Token) error {
 			symbol,
 			decimals
 		) VALUES %s;`,
-		tokens[:],
+		tokens,
 	))
 }
 
-// UpdateTokenValue updates the USD value of a token
+// UpdateTokenValue updates the USD value of a token.  Value is the price in
+// USD of a normalized token (token amount divided by 10^decimals)
 func (hdb *HistoryDB) UpdateTokenValue(tokenSymbol string, value float64) error {
 	// Sanitize symbol
 	tokenSymbol = strings.ToValidUTF8(tokenSymbol, " ")
@@ -514,7 +515,7 @@ func (hdb *HistoryDB) addAccounts(d meddler.DB, accounts []common.Account) error
 			bjj,
 			eth_addr
 		) VALUES %s;`,
-		accounts[:],
+		accounts,
 	))
 }
 
@@ -528,6 +529,37 @@ func (hdb *HistoryDB) GetAllAccounts() ([]common.Account, error) {
 	return db.SlicePtrsToSlice(accs).([]common.Account), tracerr.Wrap(err)
 }
 
+// AddAccountUpdates inserts accUpdates into the DB
+func (hdb *HistoryDB) AddAccountUpdates(accUpdates []common.AccountUpdate) error {
+	return tracerr.Wrap(hdb.addAccountUpdates(hdb.db, accUpdates))
+}
+func (hdb *HistoryDB) addAccountUpdates(d meddler.DB, accUpdates []common.AccountUpdate) error {
+	if len(accUpdates) == 0 {
+		return nil
+	}
+	return tracerr.Wrap(db.BulkInsert(
+		d,
+		`INSERT INTO account_update (
+			eth_block_num,
+			batch_num,
+			idx,
+			nonce,
+			balance
+		) VALUES %s;`,
+		accUpdates,
+	))
+}
+
+// GetAllAccountUpdates returns all the AccountUpdate from the DB
+func (hdb *HistoryDB) GetAllAccountUpdates() ([]common.AccountUpdate, error) {
+	var accUpdates []*common.AccountUpdate
+	err := meddler.QueryAll(
+		hdb.db, &accUpdates,
+		"SELECT eth_block_num, batch_num, idx, nonce, balance FROM account_update ORDER BY idx;",
+	)
+	return db.SlicePtrsToSlice(accUpdates).([]common.AccountUpdate), tracerr.Wrap(err)
+}
+
 // AddL1Txs inserts L1 txs to the DB. USD and DepositAmountUSD will be set automatically before storing the tx.
 // If the tx is originated by a coordinator, BatchNum must be provided. If it's originated by a user,
 // BatchNum should be null, and the value will be setted by a trigger when a batch forges the tx.
@@ -646,7 +678,7 @@ func (hdb *HistoryDB) addTxs(d meddler.DB, txs []txWrite) error {
 			fee,
 			nonce
 		) VALUES %s;`,
-		txs[:],
+		txs,
 	))
 }
 
@@ -781,7 +813,7 @@ func (hdb *HistoryDB) addBucketUpdates(d meddler.DB, bucketUpdates []common.Buck
 		 	block_stamp,
 		 	withdrawals
 		) VALUES %s;`,
-		bucketUpdates[:],
+		bucketUpdates,
 	))
 }
 
@@ -813,7 +845,7 @@ func (hdb *HistoryDB) addTokenExchanges(d meddler.DB, tokenExchanges []common.To
     			eth_addr,
     			value_usd
 		) VALUES %s;`,
-		tokenExchanges[:],
+		tokenExchanges,
 	))
 }
 
@@ -841,7 +873,7 @@ func (hdb *HistoryDB) addEscapeHatchWithdrawals(d meddler.DB,
 			token_addr,
 			amount
 		) VALUES %s;`,
-		escapeHatchWithdrawals[:],
+		escapeHatchWithdrawals,
 	))
 }
 
@@ -1018,6 +1050,11 @@ func (hdb *HistoryDB) AddBlockSCData(blockData *common.BlockData) (err error) {
 			return tracerr.Wrap(err)
 		}
 
+		// Add accountBalances if it exists
+		if err := hdb.addAccountUpdates(txn, batch.UpdatedAccounts); err != nil {
+			return tracerr.Wrap(err)
+		}
+
 		// Set the EffectiveAmount and EffectiveDepositAmount of all the
 		// L1UserTxs that have been forged in this batch
 		if err = hdb.setExtraInfoForgedL1UserTxs(txn, batch.L1UserTxs); err != nil {

db/historydb/historydb_test.go

@@ -377,6 +377,22 @@ func TestAccounts(t *testing.T) {
 		accs[i].Balance = nil
 		assert.Equal(t, accs[i], acc)
 	}
+	// Test AccountBalances
+	accUpdates := make([]common.AccountUpdate, len(accs))
+	for i, acc := range accs {
+		accUpdates[i] = common.AccountUpdate{
+			EthBlockNum: batches[acc.BatchNum-1].EthBlockNum,
+			BatchNum:    acc.BatchNum,
+			Idx:         acc.Idx,
+			Nonce:       common.Nonce(i),
+			Balance:     big.NewInt(int64(i)),
+		}
+	}
+	err = historyDB.AddAccountUpdates(accUpdates)
+	require.NoError(t, err)
+	fetchedAccBalances, err := historyDB.GetAllAccountUpdates()
+	require.NoError(t, err)
+	assert.Equal(t, accUpdates, fetchedAccBalances)
 }
 
 func TestTxs(t *testing.T) {
@@ -1195,7 +1211,8 @@ func TestGetMetricsAPIMoreThan24Hours(t *testing.T) {
 	set = append(set, til.Instruction{Typ: til.TypeNewBlock})
 
 	// Transfers
-	for x := 0; x < 6000; x++ {
+	const numBlocks int = 30
+	for x := 0; x < numBlocks; x++ {
 		set = append(set, til.Instruction{
 			Typ:           common.TxTypeTransfer,
 			TokenID:       common.TokenID(0),
@@ -1219,19 +1236,20 @@ func TestGetMetricsAPIMoreThan24Hours(t *testing.T) {
 	err = tc.FillBlocksExtra(blocks, &tilCfgExtra)
 	require.NoError(t, err)
 
-	const numBatches int = 6002
+	const numBatches int = 2 + numBlocks
-	const numTx int = 6003
+	const blockNum = 4 + numBlocks
-	const blockNum = 6005 - 1
 
 	// Sanity check
 	require.Equal(t, blockNum, len(blocks))
 
 	// Adding one batch per block
 	// batch frequency can be chosen
-	const frequency int = 15
+	const blockTime time.Duration = 3600 * time.Second
+	now := time.Now()
+	require.NoError(t, err)
 
 	for i := range blocks {
-		blocks[i].Block.Timestamp = time.Now().Add(-time.Second * time.Duration(frequency*(len(blocks)-i)))
+		blocks[i].Block.Timestamp = now.Add(-time.Duration(len(blocks)-1-i) * blockTime)
 		err = historyDB.AddBlockSCData(&blocks[i])
 		assert.NoError(t, err)
 	}
@@ -1239,16 +1257,10 @@ func TestGetMetricsAPIMoreThan24Hours(t *testing.T) {
 	res, err := historyDBWithACC.GetMetricsAPI(common.BatchNum(numBatches))
 	assert.NoError(t, err)
 
-	assert.Equal(t, math.Trunc((float64(numTx)/float64(numBatches-1))/0.001)*0.001, math.Trunc(res.TransactionsPerBatch/0.001)*0.001)
+	assert.InEpsilon(t, 1.0, res.TransactionsPerBatch, 0.1)
 
-	// Frequency is not exactly the desired one, some decimals may appear
+	assert.InEpsilon(t, res.BatchFrequency, float64(blockTime/time.Second), 0.1)
-	assert.GreaterOrEqual(t, res.BatchFrequency, float64(frequency))
+	assert.InEpsilon(t, 1.0/float64(blockTime/time.Second), res.TransactionsPerSecond, 0.1)
-	assert.Less(t, res.BatchFrequency, float64(frequency+1))
-	// Truncate frecuency into an int to do an exact check
-	assert.Equal(t, frequency, int(res.BatchFrequency))
-	// This may also be different in some decimals
-	// Truncate it to the third decimal to compare
-	assert.Equal(t, math.Trunc((float64(numTx)/float64(frequency*blockNum-frequency))/0.001)*0.001, math.Trunc(res.TransactionsPerSecond/0.001)*0.001)
 	assert.Equal(t, int64(3), res.TotalAccounts)
 	assert.Equal(t, int64(3), res.TotalBJJs)
 	// Til does not set fees

db/l2db/apiqueries.go

@@ -1,12 +1,18 @@
 package l2db
 
 import (
+	"fmt"
+
 	ethCommon "github.com/ethereum/go-ethereum/common"
 	"github.com/hermeznetwork/hermez-node/common"
 	"github.com/hermeznetwork/tracerr"
 	"github.com/russross/meddler"
 )
 
+var (
+	errPoolFull = fmt.Errorf("the pool is at full capacity. More transactions are not accepted currently")
+)
+
 // AddAccountCreationAuthAPI inserts an account creation authorization into the DB
 func (l2db *L2DB) AddAccountCreationAuthAPI(auth *common.AccountCreationAuth) error {
 	cancel, err := l2db.apiConnCon.Acquire()
@@ -42,20 +48,54 @@ func (l2db *L2DB) AddTxAPI(tx *PoolL2TxWrite) error {
 		return tracerr.Wrap(err)
 	}
 	defer l2db.apiConnCon.Release()
-	row := l2db.db.QueryRow(
+
-		"SELECT COUNT(*) FROM tx_pool WHERE state = $1;",
+	row := l2db.db.QueryRow(`SELECT
-		common.PoolL2TxStatePending,
+		($1::NUMERIC * token.usd * fee_percentage($2::NUMERIC)) /
-	)
+			(10.0 ^ token.decimals::NUMERIC)
-	var totalTxs uint32
+		FROM token WHERE token.token_id = $3;`,
-	if err := row.Scan(&totalTxs); err != nil {
+		tx.AmountFloat, tx.Fee, tx.TokenID)
+	var feeUSD float64
+	if err := row.Scan(&feeUSD); err != nil {
 		return tracerr.Wrap(err)
 	}
-	if totalTxs >= l2db.maxTxs {
+	if feeUSD < l2db.minFeeUSD {
-		return tracerr.New(
+		return tracerr.Wrap(fmt.Errorf("tx.feeUSD (%v) < minFeeUSD (%v)",
-			"The pool is at full capacity. More transactions are not accepted currently",
+			feeUSD, l2db.minFeeUSD))
-		)
 	}
-	return tracerr.Wrap(meddler.Insert(l2db.db, "tx_pool", tx))
+
+	// Prepare insert SQL query argument parameters
+	namesPart, err := meddler.Default.ColumnsQuoted(tx, false)
+	if err != nil {
+		return err
+	}
+	valuesPart, err := meddler.Default.PlaceholdersString(tx, false)
+	if err != nil {
+		return err
+	}
+	values, err := meddler.Default.Values(tx, false)
+	if err != nil {
+		return err
+	}
+
+	q := fmt.Sprintf(
+		`INSERT INTO tx_pool (%s)
+		SELECT %s
+		WHERE (SELECT COUNT(*) FROM tx_pool WHERE state = $%v) < $%v;`,
+		namesPart, valuesPart,
+		len(values)+1, len(values)+2) //nolint:gomnd
+	values = append(values, common.PoolL2TxStatePending, l2db.maxTxs)
+	res, err := l2db.db.Exec(q, values...)
+	if err != nil {
+		return tracerr.Wrap(err)
+	}
+	rowsAffected, err := res.RowsAffected()
+	if err != nil {
+		return tracerr.Wrap(err)
+	}
+	if rowsAffected == 0 {
+		return tracerr.Wrap(errPoolFull)
+	}
+	return nil
 }
 
 // selectPoolTxAPI select part of queries to get PoolL2TxRead

db/l2db/l2db.go

@@ -25,6 +25,7 @@ type L2DB struct {
 	safetyPeriod common.BatchNum
 	ttl          time.Duration
 	maxTxs       uint32 // limit of txs that are accepted in the pool
+	minFeeUSD    float64
 	apiConnCon   *db.APIConnectionController
 }
 
@@ -35,6 +36,7 @@ func NewL2DB(
 	db *sqlx.DB,
 	safetyPeriod common.BatchNum,
 	maxTxs uint32,
+	minFeeUSD float64,
 	TTL time.Duration,
 	apiConnCon *db.APIConnectionController,
 ) *L2DB {
@@ -43,6 +45,7 @@ func NewL2DB(
 		safetyPeriod: safetyPeriod,
 		ttl:          TTL,
 		maxTxs:       maxTxs,
+		minFeeUSD:    minFeeUSD,
 		apiConnCon:   apiConnCon,
 	}
 }
@@ -73,24 +76,6 @@ func (l2db *L2DB) GetAccountCreationAuth(addr ethCommon.Address) (*common.Accoun
 	))
 }
 
-// AddTx inserts a tx to the pool
-func (l2db *L2DB) AddTx(tx *PoolL2TxWrite) error {
-	row := l2db.db.QueryRow(
-		"SELECT COUNT(*) FROM tx_pool WHERE state = $1;",
-		common.PoolL2TxStatePending,
-	)
-	var totalTxs uint32
-	if err := row.Scan(&totalTxs); err != nil {
-		return tracerr.Wrap(err)
-	}
-	if totalTxs >= l2db.maxTxs {
-		return tracerr.New(
-			"The pool is at full capacity. More transactions are not accepted currently",
-		)
-	}
-	return tracerr.Wrap(meddler.Insert(l2db.db, "tx_pool", tx))
-}
-
 // UpdateTxsInfo updates the parameter Info of the pool transactions
 func (l2db *L2DB) UpdateTxsInfo(txs []common.PoolL2Tx) error {
 	if len(txs) == 0 {
@@ -122,9 +107,8 @@ func (l2db *L2DB) UpdateTxsInfo(txs []common.PoolL2Tx) error {
 	return nil
 }
 
-// AddTxTest inserts a tx into the L2DB. This is useful for test purposes,
+// NewPoolL2TxWriteFromPoolL2Tx creates a new PoolL2TxWrite from a PoolL2Tx
-// but in production txs will only be inserted through the API
+func NewPoolL2TxWriteFromPoolL2Tx(tx *common.PoolL2Tx) *PoolL2TxWrite {
-func (l2db *L2DB) AddTxTest(tx *common.PoolL2Tx) error {
 	// transform tx from *common.PoolL2Tx to PoolL2TxWrite
 	insertTx := &PoolL2TxWrite{
 		TxID:      tx.TxID,
@@ -166,6 +150,13 @@ func (l2db *L2DB) AddTxTest(tx *common.PoolL2Tx) error {
 	f := new(big.Float).SetInt(tx.Amount)
 	amountF, _ := f.Float64()
 	insertTx.AmountFloat = amountF
+	return insertTx
+}
+
+// AddTxTest inserts a tx into the L2DB. This is useful for test purposes,
+// but in production txs will only be inserted through the API
+func (l2db *L2DB) AddTxTest(tx *common.PoolL2Tx) error {
+	insertTx := NewPoolL2TxWriteFromPoolL2Tx(tx)
 	// insert tx
 	return tracerr.Wrap(meddler.Insert(l2db.db, "tx_pool", insertTx))
 }
@@ -176,7 +167,8 @@ tx_pool.to_bjj, tx_pool.token_id, tx_pool.amount, tx_pool.fee, tx_pool.nonce,
 tx_pool.state, tx_pool.info, tx_pool.signature, tx_pool.timestamp, rq_from_idx, 
 rq_to_idx, tx_pool.rq_to_eth_addr, tx_pool.rq_to_bjj, tx_pool.rq_token_id, tx_pool.rq_amount, 
 tx_pool.rq_fee, tx_pool.rq_nonce, tx_pool.tx_type, 
-fee_percentage(tx_pool.fee::NUMERIC) * token.usd * tx_pool.amount_f AS fee_usd, token.usd_update  
+(fee_percentage(tx_pool.fee::NUMERIC) * token.usd * tx_pool.amount_f) /
+	(10.0 ^ token.decimals::NUMERIC) AS fee_usd, token.usd_update
 FROM tx_pool INNER JOIN token ON tx_pool.token_id = token.token_id `
 
 // GetTx  return the specified Tx in common.PoolL2Tx format
@@ -354,3 +346,14 @@ func (l2db *L2DB) Purge(currentBatchNum common.BatchNum) (err error) {
 	)
 	return tracerr.Wrap(err)
 }
+
+// PurgeByExternalDelete deletes all pending transactions marked with true in
+// the `external_delete` column.  An external process can set this column to
+// true to instruct the coordinator to delete the tx when possible.
+func (l2db *L2DB) PurgeByExternalDelete() error {
+	_, err := l2db.db.Exec(
+		`DELETE from tx_pool WHERE (external_delete = true AND state = $1);`,
+		common.PoolL2TxStatePending,
+	)
+	return tracerr.Wrap(err)
+}

db/l2db/l2db_test.go

@@ -1,8 +1,8 @@
 package l2db
 
 import (
-	"math"
+	"database/sql"
-	"math/big"
+	"fmt"
 	"os"
 	"testing"
 	"time"
@@ -20,12 +20,14 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
+var decimals = uint64(3)
+var tokenValue = 1.0 // The price update gives a value of 1.0 USD to the token
 var l2DB *L2DB
 var l2DBWithACC *L2DB
 var historyDB *historydb.HistoryDB
 var tc *til.Context
 var tokens map[common.TokenID]historydb.TokenWithUSD
-var tokensValue map[common.TokenID]float64
+
 var accs map[common.Idx]common.Account
 
 func TestMain(m *testing.M) {
@@ -35,9 +37,9 @@ func TestMain(m *testing.M) {
 	if err != nil {
 		panic(err)
 	}
-	l2DB = NewL2DB(db, 10, 1000, 24*time.Hour, nil)
+	l2DB = NewL2DB(db, 10, 1000, 0.0, 24*time.Hour, nil)
 	apiConnCon := dbUtils.NewAPICnnectionController(1, time.Second)
-	l2DBWithACC = NewL2DB(db, 10, 1000, 24*time.Hour, apiConnCon)
+	l2DBWithACC = NewL2DB(db, 10, 1000, 0.0, 24*time.Hour, apiConnCon)
 	test.WipeDB(l2DB.DB())
 	historyDB = historydb.NewHistoryDB(db, nil)
 	// Run tests
@@ -58,10 +60,10 @@ func prepareHistoryDB(historyDB *historydb.HistoryDB) error {
 
 			AddToken(1)
 			AddToken(2)
-			CreateAccountDeposit(1) A: 2000
+			CreateAccountDeposit(1) A: 20000
-			CreateAccountDeposit(2) A: 2000
+			CreateAccountDeposit(2) A: 20000
-			CreateAccountDeposit(1) B: 1000
+			CreateAccountDeposit(1) B: 10000
-			CreateAccountDeposit(2) B: 1000
+			CreateAccountDeposit(2) B: 10000
 			> batchL1 
 			> batchL1
 			> block
@@ -82,15 +84,23 @@ func prepareHistoryDB(historyDB *historydb.HistoryDB) error {
 	if err != nil {
 		return tracerr.Wrap(err)
 	}
+	for i := range blocks {
+		block := &blocks[i]
+		for j := range block.Rollup.AddedTokens {
+			token := &block.Rollup.AddedTokens[j]
+			token.Name = fmt.Sprintf("Token %d", token.TokenID)
+			token.Symbol = fmt.Sprintf("TK%d", token.TokenID)
+			token.Decimals = decimals
+		}
+	}
+
 	tokens = make(map[common.TokenID]historydb.TokenWithUSD)
-	tokensValue = make(map[common.TokenID]float64)
+	// tokensValue = make(map[common.TokenID]float64)
 	accs = make(map[common.Idx]common.Account)
-	value := 5 * 5.389329
 	now := time.Now().UTC()
 	// Add all blocks except for the last one
 	for i := range blocks[:len(blocks)-1] {
-		err = historyDB.AddBlockSCData(&blocks[i])
+		if err := historyDB.AddBlockSCData(&blocks[i]); err != nil {
-		if err != nil {
 			return tracerr.Wrap(err)
 		}
 		for _, batch := range blocks[i].Rollup.Batches {
@@ -106,39 +116,38 @@ func prepareHistoryDB(historyDB *historydb.HistoryDB) error {
 				Name:        token.Name,
 				Symbol:      token.Symbol,
 				Decimals:    token.Decimals,
+				USD:         &tokenValue,
+				USDUpdate:   &now,
 			}
-			tokensValue[token.TokenID] = value / math.Pow(10, float64(token.Decimals))
-			readToken.USDUpdate = &now
-			readToken.USD = &value
 			tokens[token.TokenID] = readToken
-		}
+			// Set value to the tokens
-		// Set value to the tokens (tokens have no symbol)
+			err := historyDB.UpdateTokenValue(readToken.Symbol, *readToken.USD)
-		tokenSymbol := ""
-		err := historyDB.UpdateTokenValue(tokenSymbol, value)
 			if err != nil {
 				return tracerr.Wrap(err)
 			}
 		}
+	}
 	return nil
 }
 
 func generatePoolL2Txs() ([]common.PoolL2Tx, error) {
+	// Fee = 126 corresponds to ~10%
 	setPool := `
 			Type: PoolL2
-			PoolTransfer(1) A-B: 6 (4)
+			PoolTransfer(1) A-B: 6000 (126)
-			PoolTransfer(2) A-B: 3 (1)
+			PoolTransfer(2) A-B: 3000 (126)
-			PoolTransfer(1) B-A: 5 (2)
+			PoolTransfer(1) B-A: 5000 (126)
-			PoolTransfer(2) B-A: 10 (3)
+			PoolTransfer(2) B-A: 10000 (126)
-			PoolTransfer(1) A-B: 7 (2)
+			PoolTransfer(1) A-B: 7000 (126)
-			PoolTransfer(2) A-B: 2 (1)
+			PoolTransfer(2) A-B: 2000 (126)
-			PoolTransfer(1) B-A: 8 (2)
+			PoolTransfer(1) B-A: 8000 (126)
-			PoolTransfer(2) B-A: 1 (1)
+			PoolTransfer(2) B-A: 1000 (126)
-			PoolTransfer(1) A-B: 3 (1)
+			PoolTransfer(1) A-B: 3000 (126)
-			PoolTransferToEthAddr(2) B-A: 5 (2)
+			PoolTransferToEthAddr(2) B-A: 5000 (126)
-			PoolTransferToBJJ(2) B-A: 5 (2)
+			PoolTransferToBJJ(2) B-A: 5000 (126)
 
-			PoolExit(1) A: 5 (2)
+			PoolExit(1) A: 5000 (126)
-			PoolExit(2) B: 3 (1)
+			PoolExit(2) B: 3000 (126)
 		`
 	poolL2Txs, err := tc.GeneratePoolL2Txs(setPool)
 	if err != nil {
@@ -153,25 +162,74 @@ func TestAddTxTest(t *testing.T) {
 		log.Error("Error prepare historyDB", err)
 	}
 	poolL2Txs, err := generatePoolL2Txs()
-	assert.NoError(t, err)
+	require.NoError(t, err)
 	for i := range poolL2Txs {
 		err := l2DB.AddTxTest(&poolL2Txs[i])
-		assert.NoError(t, err)
+		require.NoError(t, err)
 		fetchedTx, err := l2DB.GetTx(poolL2Txs[i].TxID)
-		assert.NoError(t, err)
+		require.NoError(t, err)
 		assertTx(t, &poolL2Txs[i], fetchedTx)
 		nameZone, offset := fetchedTx.Timestamp.Zone()
 		assert.Equal(t, "UTC", nameZone)
 		assert.Equal(t, 0, offset)
 	}
 }
+
+func TestAddTxAPI(t *testing.T) {
+	err := prepareHistoryDB(historyDB)
+	if err != nil {
+		log.Error("Error prepare historyDB", err)
+	}
+
+	oldMaxTxs := l2DBWithACC.maxTxs
+	// set max number of pending txs that can be kept in the pool to 5
+	l2DBWithACC.maxTxs = 5
+
+	poolL2Txs, err := generatePoolL2Txs()
+	txs := make([]*PoolL2TxWrite, len(poolL2Txs))
+	for i := range poolL2Txs {
+		txs[i] = NewPoolL2TxWriteFromPoolL2Tx(&poolL2Txs[i])
+	}
+	require.NoError(t, err)
+	require.GreaterOrEqual(t, len(poolL2Txs), 8)
+	for i := range txs[:5] {
+		err := l2DBWithACC.AddTxAPI(txs[i])
+		require.NoError(t, err)
+		fetchedTx, err := l2DB.GetTx(poolL2Txs[i].TxID)
+		require.NoError(t, err)
+		assertTx(t, &poolL2Txs[i], fetchedTx)
+		nameZone, offset := fetchedTx.Timestamp.Zone()
+		assert.Equal(t, "UTC", nameZone)
+		assert.Equal(t, 0, offset)
+	}
+	err = l2DBWithACC.AddTxAPI(txs[5])
+	assert.Equal(t, errPoolFull, tracerr.Unwrap(err))
+	// reset maxTxs to original value
+	l2DBWithACC.maxTxs = oldMaxTxs
+
+	// set minFeeUSD to a high value than the tx feeUSD to test the error
+	// of inserting a tx with lower than min fee
+	oldMinFeeUSD := l2DBWithACC.minFeeUSD
+	tx := txs[5]
+	feeAmount, err := common.CalcFeeAmount(tx.Amount, tx.Fee)
+	require.NoError(t, err)
+	feeAmountUSD := common.TokensToUSD(feeAmount, decimals, tokenValue)
+	// set minFeeUSD higher than the tx fee to trigger the error
+	l2DBWithACC.minFeeUSD = feeAmountUSD + 1
+	err = l2DBWithACC.AddTxAPI(tx)
+	require.Error(t, err)
+	assert.Regexp(t, "tx.feeUSD (.*) < minFeeUSD (.*)", err.Error())
+	// reset minFeeUSD to original value
+	l2DBWithACC.minFeeUSD = oldMinFeeUSD
+}
+
 func TestUpdateTxsInfo(t *testing.T) {
 	err := prepareHistoryDB(historyDB)
 	if err != nil {
 		log.Error("Error prepare historyDB", err)
 	}
 	poolL2Txs, err := generatePoolL2Txs()
-	assert.NoError(t, err)
+	require.NoError(t, err)
 	for i := range poolL2Txs {
 		err := l2DB.AddTxTest(&poolL2Txs[i])
 		require.NoError(t, err)
@@ -185,7 +243,7 @@ func TestUpdateTxsInfo(t *testing.T) {
 
 	for i := range poolL2Txs {
 		fetchedTx, err := l2DB.GetTx(poolL2Txs[i].TxID)
-		assert.NoError(t, err)
+		require.NoError(t, err)
 		assert.Equal(t, "test", fetchedTx.Info)
 	}
 }
@@ -203,9 +261,8 @@ func assertTx(t *testing.T, expected, actual *common.PoolL2Tx) {
 		assert.Less(t, token.USDUpdate.Unix()-3, actual.AbsoluteFeeUpdate.Unix())
 		expected.AbsoluteFeeUpdate = actual.AbsoluteFeeUpdate
 		// Set expected fee
-		f := new(big.Float).SetInt(expected.Amount)
+		amountUSD := common.TokensToUSD(expected.Amount, token.Decimals, *token.USD)
-		amountF, _ := f.Float64()
+		expected.AbsoluteFee = amountUSD * expected.Fee.Percentage()
-		expected.AbsoluteFee = *token.USD * amountF * expected.Fee.Percentage()
 		test.AssertUSD(t, &expected.AbsoluteFee, &actual.AbsoluteFee)
 	}
 	assert.Equal(t, expected, actual)
@@ -230,19 +287,28 @@ func TestGetPending(t *testing.T) {
 		log.Error("Error prepare historyDB", err)
 	}
 	poolL2Txs, err := generatePoolL2Txs()
-	assert.NoError(t, err)
+	require.NoError(t, err)
 	var pendingTxs []*common.PoolL2Tx
 	for i := range poolL2Txs {
 		err := l2DB.AddTxTest(&poolL2Txs[i])
-		assert.NoError(t, err)
+		require.NoError(t, err)
 		pendingTxs = append(pendingTxs, &poolL2Txs[i])
 	}
 	fetchedTxs, err := l2DB.GetPendingTxs()
-	assert.NoError(t, err)
+	require.NoError(t, err)
 	assert.Equal(t, len(pendingTxs), len(fetchedTxs))
 	for i := range fetchedTxs {
 		assertTx(t, pendingTxs[i], &fetchedTxs[i])
 	}
+	// Check AbsoluteFee amount
+	for i := range fetchedTxs {
+		tx := &fetchedTxs[i]
+		feeAmount, err := common.CalcFeeAmount(tx.Amount, tx.Fee)
+		require.NoError(t, err)
+		feeAmountUSD := common.TokensToUSD(feeAmount,
+			tokens[tx.TokenID].Decimals, *tokens[tx.TokenID].USD)
+		assert.InEpsilon(t, feeAmountUSD, tx.AbsoluteFee, 0.01)
+	}
 }
 
 func TestStartForging(t *testing.T) {
@@ -253,13 +319,13 @@ func TestStartForging(t *testing.T) {
 		log.Error("Error prepare historyDB", err)
 	}
 	poolL2Txs, err := generatePoolL2Txs()
-	assert.NoError(t, err)
+	require.NoError(t, err)
 	var startForgingTxIDs []common.TxID
 	randomizer := 0
 	// Add txs to DB
 	for i := range poolL2Txs {
 		err := l2DB.AddTxTest(&poolL2Txs[i])
-		assert.NoError(t, err)
+		require.NoError(t, err)
 		if poolL2Txs[i].State == common.PoolL2TxStatePending && randomizer%2 == 0 {
 			startForgingTxIDs = append(startForgingTxIDs, poolL2Txs[i].TxID)
 		}
@@ -267,11 +333,11 @@ func TestStartForging(t *testing.T) {
 	}
 	// Start forging txs
 	err = l2DB.StartForging(startForgingTxIDs, fakeBatchNum)
-	assert.NoError(t, err)
+	require.NoError(t, err)
 	// Fetch txs and check that they've been updated correctly
 	for _, id := range startForgingTxIDs {
 		fetchedTx, err := l2DBWithACC.GetTxAPI(id)
-		assert.NoError(t, err)
+		require.NoError(t, err)
 		assert.Equal(t, common.PoolL2TxStateForging, fetchedTx.State)
 		assert.Equal(t, &fakeBatchNum, fetchedTx.BatchNum)
 	}
@@ -285,13 +351,13 @@ func TestDoneForging(t *testing.T) {
 		log.Error("Error prepare historyDB", err)
 	}
 	poolL2Txs, err := generatePoolL2Txs()
-	assert.NoError(t, err)
+	require.NoError(t, err)
 	var startForgingTxIDs []common.TxID
 	randomizer := 0
 	// Add txs to DB
 	for i := range poolL2Txs {
 		err := l2DB.AddTxTest(&poolL2Txs[i])
-		assert.NoError(t, err)
+		require.NoError(t, err)
 		if poolL2Txs[i].State == common.PoolL2TxStatePending && randomizer%2 == 0 {
 			startForgingTxIDs = append(startForgingTxIDs, poolL2Txs[i].TxID)
 		}
@@ -299,7 +365,7 @@ func TestDoneForging(t *testing.T) {
 	}
 	// Start forging txs
 	err = l2DB.StartForging(startForgingTxIDs, fakeBatchNum)
-	assert.NoError(t, err)
+	require.NoError(t, err)
 
 	var doneForgingTxIDs []common.TxID
 	randomizer = 0
@@ -311,12 +377,12 @@ func TestDoneForging(t *testing.T) {
 	}
 	// Done forging txs
 	err = l2DB.DoneForging(doneForgingTxIDs, fakeBatchNum)
-	assert.NoError(t, err)
+	require.NoError(t, err)
 
 	// Fetch txs and check that they've been updated correctly
 	for _, id := range doneForgingTxIDs {
 		fetchedTx, err := l2DBWithACC.GetTxAPI(id)
-		assert.NoError(t, err)
+		require.NoError(t, err)
 		assert.Equal(t, common.PoolL2TxStateForged, fetchedTx.State)
 		assert.Equal(t, &fakeBatchNum, fetchedTx.BatchNum)
 	}
@@ -330,13 +396,13 @@ func TestInvalidate(t *testing.T) {
 		log.Error("Error prepare historyDB", err)
 	}
 	poolL2Txs, err := generatePoolL2Txs()
-	assert.NoError(t, err)
+	require.NoError(t, err)
 	var invalidTxIDs []common.TxID
 	randomizer := 0
 	// Add txs to DB
 	for i := range poolL2Txs {
 		err := l2DB.AddTxTest(&poolL2Txs[i])
-		assert.NoError(t, err)
+		require.NoError(t, err)
 		if poolL2Txs[i].State != common.PoolL2TxStateInvalid && randomizer%2 == 0 {
 			randomizer++
 			invalidTxIDs = append(invalidTxIDs, poolL2Txs[i].TxID)
@@ -344,11 +410,11 @@ func TestInvalidate(t *testing.T) {
 	}
 	// Invalidate txs
 	err = l2DB.InvalidateTxs(invalidTxIDs, fakeBatchNum)
-	assert.NoError(t, err)
+	require.NoError(t, err)
 	// Fetch txs and check that they've been updated correctly
 	for _, id := range invalidTxIDs {
 		fetchedTx, err := l2DBWithACC.GetTxAPI(id)
-		assert.NoError(t, err)
+		require.NoError(t, err)
 		assert.Equal(t, common.PoolL2TxStateInvalid, fetchedTx.State)
 		assert.Equal(t, &fakeBatchNum, fetchedTx.BatchNum)
 	}
@@ -362,7 +428,7 @@ func TestInvalidateOldNonces(t *testing.T) {
 		log.Error("Error prepare historyDB", err)
 	}
 	poolL2Txs, err := generatePoolL2Txs()
-	assert.NoError(t, err)
+	require.NoError(t, err)
 	// Update Accounts currentNonce
 	var updateAccounts []common.IdxNonce
 	var currentNonce = common.Nonce(1)
@@ -379,13 +445,13 @@ func TestInvalidateOldNonces(t *testing.T) {
 			invalidTxIDs = append(invalidTxIDs, poolL2Txs[i].TxID)
 		}
 		err := l2DB.AddTxTest(&poolL2Txs[i])
-		assert.NoError(t, err)
+		require.NoError(t, err)
 	}
 	// sanity check
 	require.Greater(t, len(invalidTxIDs), 0)
 
 	err = l2DB.InvalidateOldNonces(updateAccounts, fakeBatchNum)
-	assert.NoError(t, err)
+	require.NoError(t, err)
 	// Fetch txs and check that they've been updated correctly
 	for _, id := range invalidTxIDs {
 		fetchedTx, err := l2DBWithACC.GetTxAPI(id)
@@ -407,7 +473,7 @@ func TestReorg(t *testing.T) {
 		log.Error("Error prepare historyDB", err)
 	}
 	poolL2Txs, err := generatePoolL2Txs()
-	assert.NoError(t, err)
+	require.NoError(t, err)
 
 	reorgedTxIDs := []common.TxID{}
 	nonReorgedTxIDs := []common.TxID{}
@@ -418,7 +484,7 @@ func TestReorg(t *testing.T) {
 	// Add txs to DB
 	for i := range poolL2Txs {
 		err := l2DB.AddTxTest(&poolL2Txs[i])
-		assert.NoError(t, err)
+		require.NoError(t, err)
 		if poolL2Txs[i].State == common.PoolL2TxStatePending && randomizer%2 == 0 {
 			startForgingTxIDs = append(startForgingTxIDs, poolL2Txs[i].TxID)
 			allTxRandomize = append(allTxRandomize, poolL2Txs[i].TxID)
@@ -430,7 +496,7 @@ func TestReorg(t *testing.T) {
 	}
 	// Start forging txs
 	err = l2DB.StartForging(startForgingTxIDs, lastValidBatch)
-	assert.NoError(t, err)
+	require.NoError(t, err)
 
 	var doneForgingTxIDs []common.TxID
 	randomizer = 0
@@ -455,22 +521,22 @@ func TestReorg(t *testing.T) {
 
 	// Invalidate txs BEFORE reorgBatch --> nonReorg
 	err = l2DB.InvalidateTxs(invalidTxIDs, lastValidBatch)
-	assert.NoError(t, err)
+	require.NoError(t, err)
 	// Done forging txs in reorgBatch --> Reorg
 	err = l2DB.DoneForging(doneForgingTxIDs, reorgBatch)
-	assert.NoError(t, err)
+	require.NoError(t, err)
 
 	err = l2DB.Reorg(lastValidBatch)
-	assert.NoError(t, err)
+	require.NoError(t, err)
 	for _, id := range reorgedTxIDs {
 		tx, err := l2DBWithACC.GetTxAPI(id)
-		assert.NoError(t, err)
+		require.NoError(t, err)
 		assert.Nil(t, tx.BatchNum)
 		assert.Equal(t, common.PoolL2TxStatePending, tx.State)
 	}
 	for _, id := range nonReorgedTxIDs {
 		fetchedTx, err := l2DBWithACC.GetTxAPI(id)
-		assert.NoError(t, err)
+		require.NoError(t, err)
 		assert.Equal(t, lastValidBatch, *fetchedTx.BatchNum)
 	}
 }
@@ -487,7 +553,7 @@ func TestReorg2(t *testing.T) {
 		log.Error("Error prepare historyDB", err)
 	}
 	poolL2Txs, err := generatePoolL2Txs()
-	assert.NoError(t, err)
+	require.NoError(t, err)
 
 	reorgedTxIDs := []common.TxID{}
 	nonReorgedTxIDs := []common.TxID{}
@@ -498,7 +564,7 @@ func TestReorg2(t *testing.T) {
 	// Add txs to DB
 	for i := range poolL2Txs {
 		err := l2DB.AddTxTest(&poolL2Txs[i])
-		assert.NoError(t, err)
+		require.NoError(t, err)
 		if poolL2Txs[i].State == common.PoolL2TxStatePending && randomizer%2 == 0 {
 			startForgingTxIDs = append(startForgingTxIDs, poolL2Txs[i].TxID)
 			allTxRandomize = append(allTxRandomize, poolL2Txs[i].TxID)
@@ -510,7 +576,7 @@ func TestReorg2(t *testing.T) {
 	}
 	// Start forging txs
 	err = l2DB.StartForging(startForgingTxIDs, lastValidBatch)
-	assert.NoError(t, err)
+	require.NoError(t, err)
 
 	var doneForgingTxIDs []common.TxID
 	randomizer = 0
@@ -532,22 +598,22 @@ func TestReorg2(t *testing.T) {
 	}
 	// Done forging txs BEFORE reorgBatch --> nonReorg
 	err = l2DB.DoneForging(doneForgingTxIDs, lastValidBatch)
-	assert.NoError(t, err)
+	require.NoError(t, err)
 	// Invalidate txs in reorgBatch --> Reorg
 	err = l2DB.InvalidateTxs(invalidTxIDs, reorgBatch)
-	assert.NoError(t, err)
+	require.NoError(t, err)
 
 	err = l2DB.Reorg(lastValidBatch)
-	assert.NoError(t, err)
+	require.NoError(t, err)
 	for _, id := range reorgedTxIDs {
 		tx, err := l2DBWithACC.GetTxAPI(id)
-		assert.NoError(t, err)
+		require.NoError(t, err)
 		assert.Nil(t, tx.BatchNum)
 		assert.Equal(t, common.PoolL2TxStatePending, tx.State)
 	}
 	for _, id := range nonReorgedTxIDs {
 		fetchedTx, err := l2DBWithACC.GetTxAPI(id)
-		assert.NoError(t, err)
+		require.NoError(t, err)
 		assert.Equal(t, lastValidBatch, *fetchedTx.BatchNum)
 	}
 }
@@ -563,7 +629,7 @@ func TestPurge(t *testing.T) {
 	var poolL2Tx []common.PoolL2Tx
 	for i := 0; i < generateTx; i++ {
 		poolL2TxAux, err := generatePoolL2Txs()
-		assert.NoError(t, err)
+		require.NoError(t, err)
 		poolL2Tx = append(poolL2Tx, poolL2TxAux...)
 	}
 
@@ -590,7 +656,7 @@ func TestPurge(t *testing.T) {
 			deletedIDs = append(deletedIDs, poolL2Tx[i].TxID)
 		}
 		err := l2DB.AddTxTest(&tx)
-		assert.NoError(t, err)
+		require.NoError(t, err)
 	}
 	// Set batchNum keeped txs
 	for i := range keepedIDs {
@@ -598,17 +664,17 @@ func TestPurge(t *testing.T) {
 			"UPDATE tx_pool SET batch_num = $1 WHERE tx_id = $2;",
 			safeBatchNum, keepedIDs[i],
 		)
-		assert.NoError(t, err)
+		require.NoError(t, err)
 	}
 	// Start forging txs and set batchNum
 	err = l2DB.StartForging(doneForgingTxIDs, toDeleteBatchNum)
-	assert.NoError(t, err)
+	require.NoError(t, err)
 	// Done forging txs and set batchNum
 	err = l2DB.DoneForging(doneForgingTxIDs, toDeleteBatchNum)
-	assert.NoError(t, err)
+	require.NoError(t, err)
 	// Invalidate txs and set batchNum
 	err = l2DB.InvalidateTxs(invalidTxIDs, toDeleteBatchNum)
-	assert.NoError(t, err)
+	require.NoError(t, err)
 	// Update timestamp of afterTTL txs
 	deleteTimestamp := time.Unix(time.Now().UTC().Unix()-int64(l2DB.ttl.Seconds()+float64(4*time.Second)), 0)
 	for _, id := range afterTTLIDs {
@@ -617,12 +683,12 @@ func TestPurge(t *testing.T) {
 			"UPDATE tx_pool SET timestamp = $1, state = $2 WHERE tx_id = $3;",
 			deleteTimestamp, common.PoolL2TxStatePending, id,
 		)
-		assert.NoError(t, err)
+		require.NoError(t, err)
 	}
 
 	// Purge txs
 	err = l2DB.Purge(safeBatchNum)
-	assert.NoError(t, err)
+	require.NoError(t, err)
 	// Check results
 	for _, id := range deletedIDs {
 		_, err := l2DB.GetTx(id)
@@ -630,7 +696,7 @@ func TestPurge(t *testing.T) {
 	}
 	for _, id := range keepedIDs {
 		_, err := l2DB.GetTx(id)
-		assert.NoError(t, err)
+		require.NoError(t, err)
 	}
 }
 
@@ -644,10 +710,10 @@ func TestAuth(t *testing.T) {
 	for i := 0; i < len(auths); i++ {
 		// Add to the DB
 		err := l2DB.AddAccountCreationAuth(auths[i])
-		assert.NoError(t, err)
+		require.NoError(t, err)
 		// Fetch from DB
 		auth, err := l2DB.GetAccountCreationAuth(auths[i].EthAddr)
-		assert.NoError(t, err)
+		require.NoError(t, err)
 		// Check fetched vs generated
 		assert.Equal(t, auths[i].EthAddr, auth.EthAddr)
 		assert.Equal(t, auths[i].BJJ, auth.BJJ)
@@ -665,7 +731,7 @@ func TestAddGet(t *testing.T) {
 		log.Error("Error prepare historyDB", err)
 	}
 	poolL2Txs, err := generatePoolL2Txs()
-	assert.NoError(t, err)
+	require.NoError(t, err)
 
 	// We will work with only 3 txs
 	require.GreaterOrEqual(t, len(poolL2Txs), 3)
@@ -701,3 +767,56 @@ func TestAddGet(t *testing.T) {
 		assert.Equal(t, txs[i], *dbTx)
 	}
 }
+
+func TestPurgeByExternalDelete(t *testing.T) {
+	err := prepareHistoryDB(historyDB)
+	if err != nil {
+		log.Error("Error prepare historyDB", err)
+	}
+	txs, err := generatePoolL2Txs()
+	require.NoError(t, err)
+
+	// We will work with 8 txs
+	require.GreaterOrEqual(t, len(txs), 8)
+	txs = txs[:8]
+	for i := range txs {
+		require.NoError(t, l2DB.AddTxTest(&txs[i]))
+	}
+
+	// We will recreate this scenario:
+	// tx index, status , external_delete
+	// 0       , pending, false
+	// 1       , pending, false
+	// 2       , pending, true // will be deleted
+	// 3       , pending, true // will be deleted
+	// 4       , fging  , false
+	// 5       , fging  , false
+	// 6       , fging  , true
+	// 7       , fging  , true
+
+	require.NoError(t, l2DB.StartForging(
+		[]common.TxID{txs[4].TxID, txs[5].TxID, txs[6].TxID, txs[7].TxID},
+		1))
+	_, err = l2DB.db.Exec(
+		`UPDATE tx_pool SET external_delete = true WHERE
+			tx_id IN ($1, $2, $3, $4)
+		;`,
+		txs[2].TxID, txs[3].TxID, txs[6].TxID, txs[7].TxID,
+	)
+	require.NoError(t, err)
+	require.NoError(t, l2DB.PurgeByExternalDelete())
+
+	// Query txs that are have been not deleted
+	for _, i := range []int{0, 1, 4, 5, 6, 7} {
+		txID := txs[i].TxID
+		_, err := l2DB.GetTx(txID)
+		require.NoError(t, err)
+	}
+
+	// Query txs that have been deleted
+	for _, i := range []int{2, 3} {
+		txID := txs[i].TxID
+		_, err := l2DB.GetTx(txID)
+		require.Equal(t, sql.ErrNoRows, tracerr.Unwrap(err))
+	}
+}

db/l2db/views.go

@@ -34,6 +34,7 @@ type PoolL2TxWrite struct {
 	RqFee       *common.FeeSelector    `meddler:"rq_fee"`
 	RqNonce     *common.Nonce          `meddler:"rq_nonce"`
 	Type        common.TxType          `meddler:"tx_type"`
+	ClientIP    string                 `meddler:"client_ip"`
 }
 
 // PoolTxAPI represents a L2 Tx pool with extra metadata used by the API

db/migrations/0001.sql

@@ -47,7 +47,7 @@ CREATE TABLE token (
     name VARCHAR(20) NOT NULL,
     symbol VARCHAR(10) NOT NULL,
     decimals INT NOT NULL,
-    usd NUMERIC,
+    usd NUMERIC, -- value of a normalized token (divided by 10^decimals)
     usd_update TIMESTAMP WITHOUT TIME ZONE
 );
 
@@ -100,6 +100,15 @@ CREATE TABLE account (
     eth_addr BYTEA NOT NULL
 );
 
+CREATE TABLE account_update (
+    item_id SERIAL,
+    eth_block_num BIGINT NOT NULL REFERENCES block (eth_block_num) ON DELETE CASCADE,
+    batch_num BIGINT NOT NULL REFERENCES batch (batch_num) ON DELETE CASCADE,
+    idx BIGINT NOT NULL REFERENCES account (idx) ON DELETE CASCADE,
+    nonce BIGINT NOT NULL,
+    balance BYTEA NOT NULL
+);
+
 CREATE TABLE exit_tree (
     item_id SERIAL PRIMARY KEY,
     batch_num BIGINT REFERENCES batch (batch_num) ON DELETE CASCADE,
@@ -618,7 +627,9 @@ CREATE TABLE tx_pool (
     rq_amount BYTEA,
     rq_fee SMALLINT,
     rq_nonce BIGINT,
-    tx_type VARCHAR(40) NOT NULL
+    tx_type VARCHAR(40) NOT NULL,
+    client_ip VARCHAR,
+    external_delete BOOLEAN NOT NULL DEFAULT false
 );
 
 -- +migrate StatementBegin
@@ -674,6 +685,7 @@ DROP TABLE token_exchange;
 DROP TABLE wdelayer_vars;
 DROP TABLE tx;
 DROP TABLE exit_tree;
+DROP TABLE account_update;
 DROP TABLE account;
 DROP TABLE token;
 DROP TABLE bid;

eth/ethereum.go

@@ -324,5 +324,6 @@ func (c *EthereumClient) EthCall(ctx context.Context, tx *types.Transaction,
 		Value:    tx.Value(),
 		Data:     tx.Data(),
 	}
-	return c.client.CallContract(ctx, msg, blockNum)
+	result, err := c.client.CallContract(ctx, msg, blockNum)
+	return result, tracerr.Wrap(err)
 }

eth/rollup.go

@@ -327,7 +327,7 @@ func (c *RollupClient) RollupForgeBatch(args *RollupForgeBatchArgs, auth *bind.T
 	if auth == nil {
 		auth, err = c.client.NewAuth()
 		if err != nil {
-			return nil, err
+			return nil, tracerr.Wrap(err)
 		}
 		auth.GasLimit = 1000000
 	}
@@ -393,7 +393,7 @@ func (c *RollupClient) RollupForgeBatch(args *RollupForgeBatchArgs, auth *bind.T
 		l1CoordinatorBytes, l1l2TxData, feeIdxCoordinator, args.VerifierIdx, args.L1Batch,
 		args.ProofA, args.ProofB, args.ProofC)
 	if err != nil {
-		return nil, tracerr.Wrap(fmt.Errorf("Failed Hermez.ForgeBatch: %w", err))
+		return nil, tracerr.Wrap(fmt.Errorf("Hermez.ForgeBatch: %w", err))
 	}
 	return tx, nil
 }

log/log.go

@@ -67,6 +67,11 @@ func Init(levelStr string, outputs []string) {
 
 func sprintStackTrace(st []tracerr.Frame) string {
 	builder := strings.Builder{}
+	// Skip deepest frame because it belongs to the go runtime and we don't
+	// care about it.
+	if len(st) > 0 {
+		st = st[:len(st)-1]
+	}
 	for _, f := range st {
 		builder.WriteString(fmt.Sprintf("\n%s:%d %s()", f.Path, f.Line, f.Func))
 	}

node/node.go

@@ -184,6 +184,7 @@ func NewNode(mode Mode, cfg *config.Node) (*Node, error) {
 
 	sync, err := synchronizer.NewSynchronizer(client, historyDB, stateDB, synchronizer.Config{
 		StatsRefreshPeriod:  cfg.Synchronizer.StatsRefreshPeriod.Duration,
+		StoreAccountUpdates: cfg.Synchronizer.StoreAccountUpdates,
 		ChainID:             chainIDU16,
 	})
 	if err != nil {
@@ -204,6 +205,7 @@ func NewNode(mode Mode, cfg *config.Node) (*Node, error) {
 			db,
 			cfg.Coordinator.L2DB.SafetyPeriod,
 			cfg.Coordinator.L2DB.MaxTxs,
+			cfg.Coordinator.L2DB.MinFeeUSD,
 			cfg.Coordinator.L2DB.TTL.Duration,
 			apiConnCon,
 		)
@@ -302,6 +304,7 @@ func NewNode(mode Mode, cfg *config.Node) (*Node, error) {
 				ForgeDelay:             cfg.Coordinator.ForgeDelay.Duration,
 				ForgeNoTxsDelay:        cfg.Coordinator.ForgeNoTxsDelay.Duration,
 				SyncRetryInterval:      cfg.Coordinator.SyncRetryInterval.Duration,
+				PurgeByExtDelInterval:  cfg.Coordinator.PurgeByExtDelInterval.Duration,
 				EthClientAttempts:      cfg.Coordinator.EthClient.Attempts,
 				EthClientAttemptsDelay: cfg.Coordinator.EthClient.AttemptsDelay.Duration,
 				EthNoReuseNonce:        cfg.Coordinator.EthClient.NoReuseNonce,

synchronizer/synchronizer.go

@@ -207,6 +207,7 @@ type SCConsts struct {
 // Config is the Synchronizer configuration
 type Config struct {
 	StatsRefreshPeriod  time.Duration
+	StoreAccountUpdates bool
 	ChainID             uint16
 }
 
@@ -993,6 +994,21 @@ func (s *Synchronizer) rollupSync(ethBlock *common.Block) (*common.RollupData, e
 		}
 		batchData.CreatedAccounts = processTxsOut.CreatedAccounts
 
+		if s.cfg.StoreAccountUpdates {
+			batchData.UpdatedAccounts = make([]common.AccountUpdate, 0,
+				len(processTxsOut.UpdatedAccounts))
+			for _, acc := range processTxsOut.UpdatedAccounts {
+				batchData.UpdatedAccounts = append(batchData.UpdatedAccounts,
+					common.AccountUpdate{
+						EthBlockNum: blockNum,
+						BatchNum:    batchNum,
+						Idx:         acc.Idx,
+						Nonce:       acc.Nonce,
+						Balance:     acc.Balance,
+					})
+			}
+		}
+
 		slotNum := int64(0)
 		if ethBlock.Num >= s.consts.Auction.GenesisBlockNum {
 			slotNum = (ethBlock.Num - s.consts.Auction.GenesisBlockNum) /

synchronizer/synchronizer_test.go

@@ -171,6 +171,8 @@ func checkSyncBlock(t *testing.T, s *Synchronizer, blockNum int, block, syncBloc
 			*exit = syncBatch.ExitTree[j]
 		}
 		assert.Equal(t, batch.Batch, syncBatch.Batch)
+		// Ignore updated accounts
+		syncBatch.UpdatedAccounts = nil
 		assert.Equal(t, batch, syncBatch)
 		assert.Equal(t, &batch.Batch, dbBatch) //nolint:gosec
 
@@ -345,6 +347,7 @@ func TestSyncGeneral(t *testing.T) {
 	// Create Synchronizer
 	s, err := NewSynchronizer(client, historyDB, stateDB, Config{
 		StatsRefreshPeriod:  0 * time.Second,
+		StoreAccountUpdates: true,
 	})
 	require.NoError(t, err)
 
@@ -736,6 +739,7 @@ func TestSyncForgerCommitment(t *testing.T) {
 	// Create Synchronizer
 	s, err := NewSynchronizer(client, historyDB, stateDB, Config{
 		StatsRefreshPeriod:  0 * time.Second,
+		StoreAccountUpdates: true,
 	})
 	require.NoError(t, err)
 
@@ -836,6 +840,7 @@ func TestSyncForgerCommitment(t *testing.T) {
 
 		s2, err := NewSynchronizer(client, historyDB, stateDB, Config{
 			StatsRefreshPeriod:  0 * time.Second,
+			StoreAccountUpdates: true,
 		})
 		require.NoError(t, err)
 		stats = s2.Stats()

test/zkproof/flows_test.go

@@ -75,7 +75,7 @@ func initTxSelector(t *testing.T, chainID uint16, hermezContractAddr ethCommon.A
 	pass := os.Getenv("POSTGRES_PASS")
 	db, err := dbUtils.InitSQLDB(5432, "localhost", "hermez", pass, "hermez")
 	require.NoError(t, err)
-	l2DB := l2db.NewL2DB(db, 10, 100, 24*time.Hour, nil)
+	l2DB := l2db.NewL2DB(db, 10, 100, 0.0, 24*time.Hour, nil)
 
 	dir, err := ioutil.TempDir("", "tmpSyncDB")
 	require.NoError(t, err)

txprocessor/txprocessor.go

@@ -27,6 +27,9 @@ type TxProcessor struct {
 	// AccumulatedFees contains the accumulated fees for each token (Coord
 	// Idx) in the processed batch
 	AccumulatedFees map[common.Idx]*big.Int
+	// updatedAccounts stores the last version of the account when it has
+	// been created/updated by any of the processed transactions.
+	updatedAccounts map[common.Idx]*common.Account
 	config          Config
 }
 
@@ -55,6 +58,9 @@ type ProcessTxOutput struct {
 	CreatedAccounts    []common.Account
 	CoordinatorIdxsMap map[common.TokenID]common.Idx
 	CollectedFees      map[common.TokenID]*big.Int
+	// UpdatedAccounts returns the current state of each account
+	// created/updated by any of the processed transactions.
+	UpdatedAccounts map[common.Idx]*common.Account
 }
 
 func newErrorNotEnoughBalance(tx common.Tx) error {
@@ -127,6 +133,10 @@ func (tp *TxProcessor) ProcessTxs(coordIdxs []common.Idx, l1usertxs, l1coordinat
 		return nil, tracerr.Wrap(fmt.Errorf("L1UserTx + L1CoordinatorTx (%d) can not be bigger than MaxL1Tx (%d)", len(l1usertxs)+len(l1coordinatortxs), tp.config.MaxTx))
 	}
 
+	if tp.s.Type() == statedb.TypeSynchronizer {
+		tp.updatedAccounts = make(map[common.Idx]*common.Account)
+	}
+
 	exits := make([]processedExit, nTx)
 
 	if tp.s.Type() == statedb.TypeBatchBuilder {
@@ -198,7 +208,7 @@ func (tp *TxProcessor) ProcessTxs(coordIdxs []common.Idx, l1usertxs, l1coordinat
 			}
 		}
 		if tp.s.Type() == statedb.TypeSynchronizer || tp.s.Type() == statedb.TypeBatchBuilder {
-			if exitIdx != nil && exitTree != nil {
+			if exitIdx != nil && exitTree != nil && exitAccount != nil {
 				exits[tp.i] = processedExit{
 					exit:    true,
 					newExit: newExit,
@@ -382,7 +392,7 @@ func (tp *TxProcessor) ProcessTxs(coordIdxs []common.Idx, l1usertxs, l1coordinat
 			tp.zki.EthAddr3[iFee] = common.EthAddrToBigInt(accCoord.EthAddr)
 		}
 		accCoord.Balance = new(big.Int).Add(accCoord.Balance, accumulatedFee)
-		pFee, err := tp.s.UpdateAccount(idx, accCoord)
+		pFee, err := tp.updateAccount(idx, accCoord)
 		if err != nil {
 			log.Error(err)
 			return nil, tracerr.Wrap(err)
@@ -407,6 +417,7 @@ func (tp *TxProcessor) ProcessTxs(coordIdxs []common.Idx, l1usertxs, l1coordinat
 		return nil, nil
 	}
 
+	if tp.s.Type() == statedb.TypeSynchronizer {
 		// once all txs processed (exitTree root frozen), for each Exit,
 		// generate common.ExitInfo data
 		var exitInfos []common.ExitInfo
@@ -438,8 +449,7 @@ func (tp *TxProcessor) ProcessTxs(coordIdxs []common.Idx, l1usertxs, l1coordinat
 			}
 		}
 
-	if tp.s.Type() == statedb.TypeSynchronizer {
+		// retun exitInfos, createdAccounts and collectedFees, so Synchronizer will
-		// retuTypeexitInfos, createdAccounts and collectedFees, so Synchronizer will
 		// be able to store it into HistoryDB for the concrete BatchNum
 		return &ProcessTxOutput{
 			ZKInputs:           nil,
@@ -447,6 +457,7 @@ func (tp *TxProcessor) ProcessTxs(coordIdxs []common.Idx, l1usertxs, l1coordinat
 			CreatedAccounts:    createdAccounts,
 			CoordinatorIdxsMap: coordIdxsMap,
 			CollectedFees:      collectedFees,
+			UpdatedAccounts:    tp.updatedAccounts,
 		}, nil
 	}
 
@@ -741,7 +752,7 @@ func (tp *TxProcessor) applyCreateAccount(tx *common.L1Tx) error {
 		EthAddr: tx.FromEthAddr,
 	}
 
-	p, err := tp.s.CreateAccount(common.Idx(tp.s.CurrentIdx()+1), account)
+	p, err := tp.createAccount(common.Idx(tp.s.CurrentIdx()+1), account)
 	if err != nil {
 		return tracerr.Wrap(err)
 	}
@@ -776,6 +787,28 @@ func (tp *TxProcessor) applyCreateAccount(tx *common.L1Tx) error {
 	return tp.s.SetCurrentIdx(tp.s.CurrentIdx() + 1)
 }
 
+// createAccount is a wrapper over the StateDB.CreateAccount method that also
+// stores the created account in the updatedAccounts map in case the StateDB is
+// of TypeSynchronizer
+func (tp *TxProcessor) createAccount(idx common.Idx, account *common.Account) (*merkletree.CircomProcessorProof, error) {
+	if tp.s.Type() == statedb.TypeSynchronizer {
+		account.Idx = idx
+		tp.updatedAccounts[idx] = account
+	}
+	return tp.s.CreateAccount(idx, account)
+}
+
+// updateAccount is a wrapper over the StateDB.UpdateAccount method that also
+// stores the updated account in the updatedAccounts map in case the StateDB is
+// of TypeSynchronizer
+func (tp *TxProcessor) updateAccount(idx common.Idx, account *common.Account) (*merkletree.CircomProcessorProof, error) {
+	if tp.s.Type() == statedb.TypeSynchronizer {
+		account.Idx = idx
+		tp.updatedAccounts[idx] = account
+	}
+	return tp.s.UpdateAccount(idx, account)
+}
+
 // applyDeposit updates the balance in the account of the depositer, if
 // andTransfer parameter is set to true, the method will also apply the
 // Transfer of the L1Tx/DepositTransfer
@@ -806,7 +839,7 @@ func (tp *TxProcessor) applyDeposit(tx *common.L1Tx, transfer bool) error {
 	}
 
 	// update sender account in localStateDB
-	p, err := tp.s.UpdateAccount(tx.FromIdx, accSender)
+	p, err := tp.updateAccount(tx.FromIdx, accSender)
 	if err != nil {
 		return tracerr.Wrap(err)
 	}
@@ -843,7 +876,7 @@ func (tp *TxProcessor) applyDeposit(tx *common.L1Tx, transfer bool) error {
 		accReceiver.Balance = new(big.Int).Add(accReceiver.Balance, tx.EffectiveAmount)
 
 		// update receiver account in localStateDB
-		p, err := tp.s.UpdateAccount(tx.ToIdx, accReceiver)
+		p, err := tp.updateAccount(tx.ToIdx, accReceiver)
 		if err != nil {
 			return tracerr.Wrap(err)
 		}
@@ -926,7 +959,7 @@ func (tp *TxProcessor) applyTransfer(coordIdxsMap map[common.TokenID]common.Idx,
 	}
 
 	// update sender account in localStateDB
-	pSender, err := tp.s.UpdateAccount(tx.FromIdx, accSender)
+	pSender, err := tp.updateAccount(tx.FromIdx, accSender)
 	if err != nil {
 		log.Error(err)
 		return tracerr.Wrap(err)
@@ -965,7 +998,7 @@ func (tp *TxProcessor) applyTransfer(coordIdxsMap map[common.TokenID]common.Idx,
 	accReceiver.Balance = new(big.Int).Add(accReceiver.Balance, tx.Amount)
 
 	// update receiver account in localStateDB
-	pReceiver, err := tp.s.UpdateAccount(auxToIdx, accReceiver)
+	pReceiver, err := tp.updateAccount(auxToIdx, accReceiver)
 	if err != nil {
 		return tracerr.Wrap(err)
 	}
@@ -1008,7 +1041,7 @@ func (tp *TxProcessor) applyCreateAccountDepositTransfer(tx *common.L1Tx) error
 	}
 
 	// create Account of the Sender
-	p, err := tp.s.CreateAccount(common.Idx(tp.s.CurrentIdx()+1), accSender)
+	p, err := tp.createAccount(common.Idx(tp.s.CurrentIdx()+1), accSender)
 	if err != nil {
 		return tracerr.Wrap(err)
 	}
@@ -1056,7 +1089,7 @@ func (tp *TxProcessor) applyCreateAccountDepositTransfer(tx *common.L1Tx) error
 	accReceiver.Balance = new(big.Int).Add(accReceiver.Balance, tx.EffectiveAmount)
 
 	// update receiver account in localStateDB
-	p, err = tp.s.UpdateAccount(tx.ToIdx, accReceiver)
+	p, err = tp.updateAccount(tx.ToIdx, accReceiver)
 	if err != nil {
 		return tracerr.Wrap(err)
 	}
@@ -1130,7 +1163,7 @@ func (tp *TxProcessor) applyExit(coordIdxsMap map[common.TokenID]common.Idx,
 		}
 	}
 
-	p, err := tp.s.UpdateAccount(tx.FromIdx, acc)
+	p, err := tp.updateAccount(tx.FromIdx, acc)
 	if err != nil {
 		return nil, false, tracerr.Wrap(err)
 	}
@@ -1141,6 +1174,11 @@ func (tp *TxProcessor) applyExit(coordIdxsMap map[common.TokenID]common.Idx,
 	if exitTree == nil {
 		return nil, false, nil
 	}
+	if tx.Amount.Cmp(big.NewInt(0)) == 0 { // Amount == 0
+		// if the Exit Amount==0, the Exit is not added to the ExitTree
+		return nil, false, nil
+	}
+
 	exitAccount, err := statedb.GetAccountInTreeDB(exitTree.DB(), tx.FromIdx)
 	if tracerr.Unwrap(err) == db.ErrNotFound {
 		// 1a. if idx does not exist in exitTree:

txprocessor/txprocessor_test.go

@@ -4,6 +4,7 @@ import (
 	"io/ioutil"
 	"math/big"
 	"os"
+	"sort"
 	"testing"
 
 	ethCommon "github.com/ethereum/go-ethereum/common"
@@ -911,3 +912,198 @@ func TestTwoExits(t *testing.T) {
 
 	assert.Equal(t, ptOuts[3].ExitInfos[0].MerkleProof, ptOuts2[3].ExitInfos[0].MerkleProof)
 }
+
+func TestExitOf0Amount(t *testing.T) {
+	// Test to check that when doing an Exit with amount 0 the Exit Root
+	// does not change (as there is no new Exit Leaf created)
+
+	dir, err := ioutil.TempDir("", "tmpdb")
+	require.NoError(t, err)
+	defer assert.NoError(t, os.RemoveAll(dir))
+
+	sdb, err := statedb.NewStateDB(statedb.Config{Path: dir, Keep: 128,
+		Type: statedb.TypeBatchBuilder, NLevels: 32})
+	assert.NoError(t, err)
+
+	chainID := uint16(1)
+
+	tc := til.NewContext(chainID, common.RollupConstMaxL1UserTx)
+
+	set := `
+		Type: Blockchain
+
+		CreateAccountDeposit(0) A: 100
+		CreateAccountDeposit(0) B: 100
+
+		> batchL1 // batch1: freeze L1User{2}
+		> batchL1 // batch2: forge L1User{2}
+
+		ForceExit(0) A: 10
+		ForceExit(0) B: 0
+
+		> batchL1 // batch3: freeze L1User{2}
+		> batchL1 // batch4: forge L1User{2}
+
+		ForceExit(0) A: 10
+
+		> batchL1 // batch5: freeze L1User{1}
+		> batchL1 // batch6: forge L1User{1}
+
+		ForceExit(0) A: 0
+		> batchL1 // batch7: freeze L1User{1}
+		> batchL1 // batch8: forge L1User{1}
+		> block
+	`
+	blocks, err := tc.GenerateBlocks(set)
+	require.NoError(t, err)
+	err = tc.FillBlocksExtra(blocks, &til.ConfigExtra{})
+	require.NoError(t, err)
+	err = tc.FillBlocksForgedL1UserTxs(blocks)
+	require.NoError(t, err)
+
+	// Sanity check
+	require.Equal(t, 2, len(blocks[0].Rollup.Batches[1].L1UserTxs))
+	require.Equal(t, 2, len(blocks[0].Rollup.Batches[3].L1UserTxs))
+	require.Equal(t, big.NewInt(10), blocks[0].Rollup.Batches[3].L1UserTxs[0].Amount)
+	require.Equal(t, big.NewInt(0), blocks[0].Rollup.Batches[3].L1UserTxs[1].Amount)
+
+	config := Config{
+		NLevels:  32,
+		MaxFeeTx: 64,
+		MaxTx:    512,
+		MaxL1Tx:  16,
+		ChainID:  chainID,
+	}
+	tp := NewTxProcessor(sdb, config)
+
+	// For this test are only processed the batches with transactions:
+	// - Batch2, equivalent to Batches[1]
+	// - Batch4, equivalent to Batches[3]
+	// - Batch6, equivalent to Batches[5]
+	// - Batch8, equivalent to Batches[7]
+
+	// process Batch2:
+	_, err = tp.ProcessTxs(nil, blocks[0].Rollup.Batches[1].L1UserTxs, nil, nil)
+	require.NoError(t, err)
+	// process Batch4:
+	ptOut, err := tp.ProcessTxs(nil, blocks[0].Rollup.Batches[3].L1UserTxs, nil, nil)
+	require.NoError(t, err)
+	assert.Equal(t, "14329759303391468223438874789317921522067594445474390443816827472846339238908", ptOut.ZKInputs.Metadata.NewExitRootRaw.BigInt().String())
+	exitRootBatch4 := ptOut.ZKInputs.Metadata.NewExitRootRaw.BigInt().String()
+
+	// process Batch6:
+	ptOut, err = tp.ProcessTxs(nil, blocks[0].Rollup.Batches[5].L1UserTxs, nil, nil)
+	require.NoError(t, err)
+	assert.Equal(t, "14329759303391468223438874789317921522067594445474390443816827472846339238908", ptOut.ZKInputs.Metadata.NewExitRootRaw.BigInt().String())
+	// Expect that the ExitRoot for the Batch6 will be equal than for the
+	// Batch4, as the Batch4 & Batch6 have the same tx with Exit Amount=10,
+	// and Batch4 has a 2nd tx with Exit Amount=0.
+	assert.Equal(t, exitRootBatch4, ptOut.ZKInputs.Metadata.NewExitRootRaw.BigInt().String())
+
+	// For the Batch8, as there is only 1 exit with Amount=0, the ExitRoot
+	// should be 0.
+	// process Batch8:
+	ptOut, err = tp.ProcessTxs(nil, blocks[0].Rollup.Batches[7].L1UserTxs, nil, nil)
+	require.NoError(t, err)
+	assert.Equal(t, "0", ptOut.ZKInputs.Metadata.NewExitRootRaw.BigInt().String())
+}
+
+func TestUpdatedAccounts(t *testing.T) {
+	dir, err := ioutil.TempDir("", "tmpdb")
+	require.NoError(t, err)
+	defer assert.NoError(t, os.RemoveAll(dir))
+
+	sdb, err := statedb.NewStateDB(statedb.Config{Path: dir, Keep: 128,
+		Type: statedb.TypeSynchronizer, NLevels: 32})
+	assert.NoError(t, err)
+
+	set := `
+Type: Blockchain
+AddToken(1)
+CreateAccountCoordinator(0) Coord // 256
+CreateAccountCoordinator(1) Coord // 257
+> batch // 1
+CreateAccountDeposit(0) A: 50 // 258
+CreateAccountDeposit(0) B: 60 // 259
+CreateAccountDeposit(1) A: 70 // 260
+CreateAccountDeposit(1) B: 80 // 261
+> batchL1 // 2
+> batchL1 // 3
+Transfer(0) A-B: 5 (126)
+> batch // 4
+Exit(1) B: 5 (126)
+> batch // 5
+> block
+	`
+
+	chainID := uint16(0)
+	tc := til.NewContext(chainID, common.RollupConstMaxL1UserTx)
+	blocks, err := tc.GenerateBlocks(set)
+	require.NoError(t, err)
+	tilCfgExtra := til.ConfigExtra{
+		BootCoordAddr: ethCommon.HexToAddress("0xE39fEc6224708f0772D2A74fd3f9055A90E0A9f2"),
+		CoordUser:     "Coord",
+	}
+	err = tc.FillBlocksExtra(blocks, &tilCfgExtra)
+	require.NoError(t, err)
+	tc.FillBlocksL1UserTxsBatchNum(blocks)
+	err = tc.FillBlocksForgedL1UserTxs(blocks)
+	require.NoError(t, err)
+
+	require.Equal(t, 5, len(blocks[0].Rollup.Batches))
+
+	config := Config{
+		NLevels:  32,
+		MaxFeeTx: 64,
+		MaxTx:    512,
+		MaxL1Tx:  16,
+		ChainID:  chainID,
+	}
+	tp := NewTxProcessor(sdb, config)
+
+	sortedKeys := func(m map[common.Idx]*common.Account) []int {
+		keys := make([]int, 0)
+		for k := range m {
+			keys = append(keys, int(k))
+		}
+		sort.Ints(keys)
+		return keys
+	}
+
+	for _, batch := range blocks[0].Rollup.Batches {
+		l2Txs := common.L2TxsToPoolL2Txs(batch.L2Txs)
+		ptOut, err := tp.ProcessTxs(batch.Batch.FeeIdxsCoordinator, batch.L1UserTxs,
+			batch.L1CoordinatorTxs, l2Txs)
+		require.NoError(t, err)
+		switch batch.Batch.BatchNum {
+		case 1:
+			assert.Equal(t, 2, len(ptOut.UpdatedAccounts))
+			assert.Equal(t, []int{256, 257}, sortedKeys(ptOut.UpdatedAccounts))
+		case 2:
+			assert.Equal(t, 0, len(ptOut.UpdatedAccounts))
+			assert.Equal(t, []int{}, sortedKeys(ptOut.UpdatedAccounts))
+		case 3:
+			assert.Equal(t, 4, len(ptOut.UpdatedAccounts))
+			assert.Equal(t, []int{258, 259, 260, 261}, sortedKeys(ptOut.UpdatedAccounts))
+		case 4:
+			assert.Equal(t, 2+1, len(ptOut.UpdatedAccounts))
+			assert.Equal(t, []int{256, 258, 259}, sortedKeys(ptOut.UpdatedAccounts))
+		case 5:
+			assert.Equal(t, 1+1, len(ptOut.UpdatedAccounts))
+			assert.Equal(t, []int{257, 261}, sortedKeys(ptOut.UpdatedAccounts))
+		}
+		for idx, updAcc := range ptOut.UpdatedAccounts {
+			acc, err := sdb.GetAccount(idx)
+			require.NoError(t, err)
+			// If acc.Balance is 0, set it to 0 with big.NewInt so
+			// that the comparison succeeds.  Without this, the
+			// comparison will not succeed because acc.Balance is
+			// set from a slice, and thus the internal big.Int
+			// buffer is not nil (big.Int.abs)
+			if acc.Balance.BitLen() == 0 {
+				acc.Balance = big.NewInt(0)
+			}
+			assert.Equal(t, acc, updAcc)
+		}
+	}
+}

txselector/txselector.go

@@ -18,20 +18,6 @@ import (
 	"github.com/iden3/go-iden3-crypto/babyjub"
 )
 
-// txs implements the interface Sort for an array of Tx, and sorts the txs by
-// absolute fee
-type txs []common.PoolL2Tx
-
-func (t txs) Len() int {
-	return len(t)
-}
-func (t txs) Swap(i, j int) {
-	t[i], t[j] = t[j], t[i]
-}
-func (t txs) Less(i, j int) bool {
-	return t[i].AbsoluteFee > t[j].AbsoluteFee
-}
-
 // CoordAccount contains the data of the Coordinator account, that will be used
 // to create new transactions of CreateAccountDeposit type to add new TokenID
 // accounts for the Coordinator to receive the fees.
@@ -191,14 +177,16 @@ func (txsel *TxSelector) GetL1L2TxSelection(selectionConfig *SelectionConfig,
 	}
 
 	// discardedL2Txs contains an array of the L2Txs that have not been selected in this Batch
-	var discardedL2Txs []common.PoolL2Tx
 
 	var l1CoordinatorTxs []common.L1Tx
 	positionL1 := len(l1UserTxs)
 	var accAuths [][]byte
 
 	// sort l2TxsRaw (cropping at MaxTx at this point)
-	l2Txs0 := txsel.getL2Profitable(l2TxsRaw, selectionConfig.TxProcessorConfig.MaxTx)
+	l2Txs0, discardedL2Txs := txsel.getL2Profitable(l2TxsRaw, selectionConfig.TxProcessorConfig.MaxTx)
+	for i := range discardedL2Txs {
+		discardedL2Txs[i].Info = "Tx not selected due to low absolute fee"
+	}
 
 	noncesMap := make(map[common.Idx]common.Nonce)
 	var l2Txs []common.PoolL2Tx
@@ -590,11 +578,22 @@ func checkAlreadyPendingToCreate(l1CoordinatorTxs []common.L1Tx, tokenID common.
 }
 
 // getL2Profitable returns the profitable selection of L2Txssorted by Nonce
-func (txsel *TxSelector) getL2Profitable(l2Txs []common.PoolL2Tx, max uint32) []common.PoolL2Tx {
+func (txsel *TxSelector) getL2Profitable(l2Txs []common.PoolL2Tx, max uint32) ([]common.PoolL2Tx,
-	// Sort by absolute fee
+	[]common.PoolL2Tx) {
-	sort.Sort(txs(l2Txs))
+	// First sort by nonce so that txs from the same account are sorted so
+	// that they could be applied in succession.
+	sort.Slice(l2Txs, func(i, j int) bool {
+		return l2Txs[i].Nonce < l2Txs[j].Nonce
+	})
+	// Sort by absolute fee with SliceStable, so that txs with same
+	// AbsoluteFee are not rearranged and nonce order is kept in such case
+	sort.SliceStable(l2Txs, func(i, j int) bool {
+		return l2Txs[i].AbsoluteFee > l2Txs[j].AbsoluteFee
+	})
 
+	discardedL2Txs := []common.PoolL2Tx{}
 	if len(l2Txs) > int(max) {
+		discardedL2Txs = l2Txs[max:]
 		l2Txs = l2Txs[:max]
 	}
 
@@ -603,9 +602,9 @@ func (txsel *TxSelector) getL2Profitable(l2Txs []common.PoolL2Tx, max uint32) []
 	// Account is sorted, but the l2Txs can not be grouped by sender Account
 	// neither by Fee. This is because later on the Nonces will need to be
 	// sequential for the zkproof generation.
-	sort.SliceStable(l2Txs, func(i, j int) bool {
+	sort.Slice(l2Txs, func(i, j int) bool {
 		return l2Txs[i].Nonce < l2Txs[j].Nonce
 	})
 
-	return l2Txs
+	return l2Txs, discardedL2Txs
 }

txselector/txselector_test.go

@@ -29,7 +29,7 @@ func initTest(t *testing.T, chainID uint16, hermezContractAddr ethCommon.Address
 	pass := os.Getenv("POSTGRES_PASS")
 	db, err := dbUtils.InitSQLDB(5432, "localhost", "hermez", pass, "hermez")
 	require.NoError(t, err)
-	l2DB := l2db.NewL2DB(db, 10, 100, 24*time.Hour, nil)
+	l2DB := l2db.NewL2DB(db, 10, 100, 0.0, 24*time.Hour, nil)
 
 	dir, err := ioutil.TempDir("", "tmpdb")
 	require.NoError(t, err)
@@ -658,7 +658,7 @@ func TestTransferManyFromSameAccount(t *testing.T) {
 	tpc := txprocessor.Config{
 		NLevels:  16,
 		MaxFeeTx: 10,
-		MaxTx:    20,
+		MaxTx:    10,
 		MaxL1Tx:  10,
 		ChainID:  chainID,
 	}
@@ -683,13 +683,17 @@ func TestTransferManyFromSameAccount(t *testing.T) {
 	PoolTransfer(0) A-B: 10 (126) // 6
 	PoolTransfer(0) A-B: 10 (126) // 7
 	PoolTransfer(0) A-B: 10 (126) // 8
+	PoolTransfer(0) A-B: 10 (126) // 9
+	PoolTransfer(0) A-B: 10 (126) // 10
+	PoolTransfer(0) A-B: 10 (126) // 11
 	`
 	poolL2Txs, err := tc.GeneratePoolL2Txs(batchPoolL2)
 	require.NoError(t, err)
+	require.Equal(t, 11, len(poolL2Txs))
 
 	// reorder poolL2Txs so that nonces are not sorted
 	poolL2Txs[0], poolL2Txs[7] = poolL2Txs[7], poolL2Txs[0]
-	poolL2Txs[1], poolL2Txs[6] = poolL2Txs[6], poolL2Txs[1]
+	poolL2Txs[1], poolL2Txs[10] = poolL2Txs[10], poolL2Txs[1]
 
 	// add the PoolL2Txs to the l2DB
 	addL2Txs(t, txsel, poolL2Txs)
@@ -699,8 +703,9 @@ func TestTransferManyFromSameAccount(t *testing.T) {
 	require.NoError(t, err)
 	assert.Equal(t, 3, len(oL1UserTxs))
 	require.Equal(t, 0, len(oL1CoordTxs))
-	assert.Equal(t, 8, len(oL2Txs))
+	assert.Equal(t, 7, len(oL2Txs))
-	assert.Equal(t, 0, len(discardedL2Txs))
+	assert.Equal(t, 1, len(discardedL2Txs))
+
 	err = txsel.l2db.StartForging(common.TxIDsFromPoolL2Txs(oL2Txs), txsel.localAccountsDB.CurrentBatch())
 	require.NoError(t, err)
 }