les: fix UDP connection query (#22451)

This PR fixes multiple issues with the UDP connection pre-negotiation feature:

- the enable condition was wrong (it checked the existence of the DiscV5 struct where it wasn't initialized yet, disabling the feature even if discv5 was enabled)
- the server pool queried already connected nodes when the discovery iterators returned them again
- servers responded positively before they were synced and really willing to accept connections

Metrics are also added on the server side that count the positive and negative replies to served connection queries.
This commit is contained in:
Felföldi Zsolt 2021-03-16 12:53:54 +01:00 committed by GitHub
parent 94ab4ea341
commit 62d8022b51
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
8 changed files with 112 additions and 78 deletions

View File

@ -73,8 +73,9 @@ type LightEthereum struct {
accountManager *accounts.Manager
netRPCService *ethapi.PublicNetAPI
p2pServer *p2p.Server
p2pConfig *p2p.Config
p2pServer *p2p.Server
p2pConfig *p2p.Config
udpEnabled bool
}
// New creates an instance of the light client.
@ -113,10 +114,11 @@ func New(stack *node.Node, config *ethconfig.Config) (*LightEthereum, error) {
bloomIndexer: core.NewBloomIndexer(chainDb, params.BloomBitsBlocksClient, params.HelperTrieConfirmations),
p2pServer: stack.Server(),
p2pConfig: &stack.Config().P2P,
udpEnabled: stack.Config().P2P.DiscoveryV5,
}
var prenegQuery vfc.QueryFunc
if leth.p2pServer.DiscV5 != nil {
if leth.udpEnabled {
prenegQuery = leth.prenegQuery
}
leth.serverPool, leth.serverPoolIterator = vfc.NewServerPool(lesDb, []byte("serverpool:"), time.Second, prenegQuery, &mclock.System{}, config.UltraLightServers, requestList)
@ -198,7 +200,7 @@ func New(stack *node.Node, config *ethconfig.Config) (*LightEthereum, error) {
// VfluxRequest sends a batch of requests to the given node through discv5 UDP TalkRequest and returns the responses
func (s *LightEthereum) VfluxRequest(n *enode.Node, reqs vflux.Requests) vflux.Replies {
if s.p2pServer.DiscV5 == nil {
if !s.udpEnabled {
return nil
}
reqsEnc, _ := rlp.EncodeToBytes(&reqs)
@ -215,7 +217,7 @@ func (s *LightEthereum) VfluxRequest(n *enode.Node, reqs vflux.Requests) vflux.R
func (s *LightEthereum) vfxVersion(n *enode.Node) uint {
if n.Seq() == 0 {
var err error
if s.p2pServer.DiscV5 == nil {
if !s.udpEnabled {
return 0
}
if n, err = s.p2pServer.DiscV5.RequestENR(n); n != nil && err == nil && n.Seq() != 0 {
@ -346,7 +348,11 @@ func (s *LightEthereum) Protocols() []p2p.Protocol {
func (s *LightEthereum) Start() error {
log.Warn("Light client mode is an experimental feature")
discovery, err := s.setupDiscovery(s.p2pConfig)
if s.udpEnabled && s.p2pServer.DiscV5 == nil {
s.udpEnabled = false
log.Error("Discovery v5 is not initialized")
}
discovery, err := s.setupDiscovery()
if err != nil {
return err
}

View File

@ -72,6 +72,7 @@ type clientPool struct {
clock mclock.Clock
closed bool
removePeer func(enode.ID)
synced func() bool
ns *nodestate.NodeStateMachine
pp *vfs.PriorityPool
bt *vfs.BalanceTracker
@ -107,7 +108,7 @@ type clientInfo struct {
}
// newClientPool creates a new client pool
func newClientPool(ns *nodestate.NodeStateMachine, lesDb ethdb.Database, minCap uint64, connectedBias time.Duration, clock mclock.Clock, removePeer func(enode.ID)) *clientPool {
func newClientPool(ns *nodestate.NodeStateMachine, lesDb ethdb.Database, minCap uint64, connectedBias time.Duration, clock mclock.Clock, removePeer func(enode.ID), synced func() bool) *clientPool {
pool := &clientPool{
ns: ns,
BalanceTrackerSetup: balanceTrackerSetup,
@ -116,6 +117,7 @@ func newClientPool(ns *nodestate.NodeStateMachine, lesDb ethdb.Database, minCap
minCap: minCap,
connectedBias: connectedBias,
removePeer: removePeer,
synced: synced,
}
pool.bt = vfs.NewBalanceTracker(ns, balanceTrackerSetup, lesDb, clock, &utils.Expirer{}, &utils.Expirer{})
pool.pp = vfs.NewPriorityPool(ns, priorityPoolSetup, clock, minCap, connectedBias, 4)
@ -396,6 +398,13 @@ func (f *clientPool) serveCapQuery(id enode.ID, freeID string, data []byte) []by
if l := len(req.AddTokens); l == 0 || l > vflux.CapacityQueryMaxLen {
return nil
}
result := make(vflux.CapacityQueryReply, len(req.AddTokens))
if !f.synced() {
capacityQueryZeroMeter.Mark(1)
reply, _ := rlp.EncodeToBytes(&result)
return reply
}
node := f.ns.GetNode(id)
if node == nil {
node = enode.SignNull(&enr.Record{}, id)
@ -416,7 +425,6 @@ func (f *clientPool) serveCapQuery(id enode.ID, freeID string, data []byte) []by
}
// use vfs.CapacityCurve to answer request for multiple newly bought token amounts
curve := f.pp.GetCapacityCurve().Exclude(id)
result := make(vflux.CapacityQueryReply, len(req.AddTokens))
bias := time.Second * time.Duration(req.Bias)
if f.connectedBias > bias {
bias = f.connectedBias
@ -434,6 +442,12 @@ func (f *clientPool) serveCapQuery(id enode.ID, freeID string, data []byte) []by
result[i] = 0
}
}
// add first result to metrics (don't care about priority client multi-queries yet)
if result[0] == 0 {
capacityQueryZeroMeter.Mark(1)
} else {
capacityQueryNonZeroMeter.Mark(1)
}
reply, _ := rlp.EncodeToBytes(&result)
return reply
}

View File

@ -133,7 +133,7 @@ func testClientPool(t *testing.T, activeLimit, clientCount, paidCount int, rando
disconnFn = func(id enode.ID) {
disconnCh <- int(id[0]) + int(id[1])<<8
}
pool = newClientPool(testStateMachine(), db, 1, 0, &clock, disconnFn)
pool = newClientPool(testStateMachine(), db, 1, 0, &clock, disconnFn, alwaysTrueFn)
)
pool.ns.Start()
@ -239,7 +239,7 @@ func TestConnectPaidClient(t *testing.T) {
clock mclock.Simulated
db = rawdb.NewMemoryDatabase()
)
pool := newClientPool(testStateMachine(), db, 1, defaultConnectedBias, &clock, func(id enode.ID) {})
pool := newClientPool(testStateMachine(), db, 1, defaultConnectedBias, &clock, func(id enode.ID) {}, alwaysTrueFn)
pool.ns.Start()
defer pool.stop()
pool.setLimits(10, uint64(10))
@ -255,7 +255,7 @@ func TestConnectPaidClientToSmallPool(t *testing.T) {
clock mclock.Simulated
db = rawdb.NewMemoryDatabase()
)
pool := newClientPool(testStateMachine(), db, 1, defaultConnectedBias, &clock, func(id enode.ID) {})
pool := newClientPool(testStateMachine(), db, 1, defaultConnectedBias, &clock, func(id enode.ID) {}, alwaysTrueFn)
pool.ns.Start()
defer pool.stop()
pool.setLimits(10, uint64(10)) // Total capacity limit is 10
@ -274,7 +274,7 @@ func TestConnectPaidClientToFullPool(t *testing.T) {
db = rawdb.NewMemoryDatabase()
)
removeFn := func(enode.ID) {} // Noop
pool := newClientPool(testStateMachine(), db, 1, defaultConnectedBias, &clock, removeFn)
pool := newClientPool(testStateMachine(), db, 1, defaultConnectedBias, &clock, removeFn, alwaysTrueFn)
pool.ns.Start()
defer pool.stop()
pool.setLimits(10, uint64(10)) // Total capacity limit is 10
@ -304,7 +304,7 @@ func TestPaidClientKickedOut(t *testing.T) {
removeFn := func(id enode.ID) {
kickedCh <- int(id[0])
}
pool := newClientPool(testStateMachine(), db, 1, defaultConnectedBias, &clock, removeFn)
pool := newClientPool(testStateMachine(), db, 1, defaultConnectedBias, &clock, removeFn, alwaysTrueFn)
pool.ns.Start()
pool.bt.SetExpirationTCs(0, 0)
defer pool.stop()
@ -335,7 +335,7 @@ func TestConnectFreeClient(t *testing.T) {
clock mclock.Simulated
db = rawdb.NewMemoryDatabase()
)
pool := newClientPool(testStateMachine(), db, 1, defaultConnectedBias, &clock, func(id enode.ID) {})
pool := newClientPool(testStateMachine(), db, 1, defaultConnectedBias, &clock, func(id enode.ID) {}, alwaysTrueFn)
pool.ns.Start()
defer pool.stop()
pool.setLimits(10, uint64(10))
@ -352,7 +352,7 @@ func TestConnectFreeClientToFullPool(t *testing.T) {
db = rawdb.NewMemoryDatabase()
)
removeFn := func(enode.ID) {} // Noop
pool := newClientPool(testStateMachine(), db, 1, defaultConnectedBias, &clock, removeFn)
pool := newClientPool(testStateMachine(), db, 1, defaultConnectedBias, &clock, removeFn, alwaysTrueFn)
pool.ns.Start()
defer pool.stop()
pool.setLimits(10, uint64(10)) // Total capacity limit is 10
@ -382,7 +382,7 @@ func TestFreeClientKickedOut(t *testing.T) {
kicked = make(chan int, 100)
)
removeFn := func(id enode.ID) { kicked <- int(id[0]) }
pool := newClientPool(testStateMachine(), db, 1, defaultConnectedBias, &clock, removeFn)
pool := newClientPool(testStateMachine(), db, 1, defaultConnectedBias, &clock, removeFn, alwaysTrueFn)
pool.ns.Start()
defer pool.stop()
pool.setLimits(10, uint64(10)) // Total capacity limit is 10
@ -424,7 +424,7 @@ func TestPositiveBalanceCalculation(t *testing.T) {
kicked = make(chan int, 10)
)
removeFn := func(id enode.ID) { kicked <- int(id[0]) } // Noop
pool := newClientPool(testStateMachine(), db, 1, defaultConnectedBias, &clock, removeFn)
pool := newClientPool(testStateMachine(), db, 1, defaultConnectedBias, &clock, removeFn, alwaysTrueFn)
pool.ns.Start()
defer pool.stop()
pool.setLimits(10, uint64(10)) // Total capacity limit is 10
@ -448,7 +448,7 @@ func TestDowngradePriorityClient(t *testing.T) {
kicked = make(chan int, 10)
)
removeFn := func(id enode.ID) { kicked <- int(id[0]) } // Noop
pool := newClientPool(testStateMachine(), db, 1, defaultConnectedBias, &clock, removeFn)
pool := newClientPool(testStateMachine(), db, 1, defaultConnectedBias, &clock, removeFn, alwaysTrueFn)
pool.ns.Start()
defer pool.stop()
pool.setLimits(10, uint64(10)) // Total capacity limit is 10
@ -483,7 +483,7 @@ func TestNegativeBalanceCalculation(t *testing.T) {
clock mclock.Simulated
db = rawdb.NewMemoryDatabase()
)
pool := newClientPool(testStateMachine(), db, 1, defaultConnectedBias, &clock, func(id enode.ID) {})
pool := newClientPool(testStateMachine(), db, 1, defaultConnectedBias, &clock, func(id enode.ID) {}, alwaysTrueFn)
pool.ns.Start()
defer pool.stop()
pool.setLimits(10, uint64(10)) // Total capacity limit is 10
@ -521,7 +521,7 @@ func TestInactiveClient(t *testing.T) {
clock mclock.Simulated
db = rawdb.NewMemoryDatabase()
)
pool := newClientPool(testStateMachine(), db, 1, defaultConnectedBias, &clock, func(id enode.ID) {})
pool := newClientPool(testStateMachine(), db, 1, defaultConnectedBias, &clock, func(id enode.ID) {}, alwaysTrueFn)
pool.ns.Start()
defer pool.stop()
pool.setLimits(2, uint64(2))

View File

@ -18,7 +18,6 @@ package les
import (
"github.com/ethereum/go-ethereum/core/forkid"
"github.com/ethereum/go-ethereum/p2p"
"github.com/ethereum/go-ethereum/p2p/dnsdisc"
"github.com/ethereum/go-ethereum/p2p/enode"
"github.com/ethereum/go-ethereum/rlp"
@ -42,7 +41,7 @@ type ethEntry struct {
func (ethEntry) ENRKey() string { return "eth" }
// setupDiscovery creates the node discovery source for the eth protocol.
func (eth *LightEthereum) setupDiscovery(cfg *p2p.Config) (enode.Iterator, error) {
func (eth *LightEthereum) setupDiscovery() (enode.Iterator, error) {
it := enode.NewFairMix(0)
// Enable DNS discovery.
@ -56,7 +55,7 @@ func (eth *LightEthereum) setupDiscovery(cfg *p2p.Config) (enode.Iterator, error
}
// Enable DHT.
if cfg.DiscoveryV5 && eth.p2pServer.DiscV5 != nil {
if eth.udpEnabled {
it.AddSource(eth.p2pServer.DiscV5.RandomNodes())
}

View File

@ -73,10 +73,12 @@ var (
serverConnectionGauge = metrics.NewRegisteredGauge("les/connection/server", nil)
clientConnectionGauge = metrics.NewRegisteredGauge("les/connection/client", nil)
totalCapacityGauge = metrics.NewRegisteredGauge("les/server/totalCapacity", nil)
totalRechargeGauge = metrics.NewRegisteredGauge("les/server/totalRecharge", nil)
totalConnectedGauge = metrics.NewRegisteredGauge("les/server/totalConnected", nil)
blockProcessingTimer = metrics.NewRegisteredTimer("les/server/blockProcessingTime", nil)
totalCapacityGauge = metrics.NewRegisteredGauge("les/server/totalCapacity", nil)
totalRechargeGauge = metrics.NewRegisteredGauge("les/server/totalRecharge", nil)
totalConnectedGauge = metrics.NewRegisteredGauge("les/server/totalConnected", nil)
blockProcessingTimer = metrics.NewRegisteredTimer("les/server/blockProcessingTime", nil)
capacityQueryZeroMeter = metrics.NewRegisteredMeter("les/server/capQueryZero", nil)
capacityQueryNonZeroMeter = metrics.NewRegisteredMeter("les/server/capQueryNonZero", nil)
requestServedMeter = metrics.NewRegisteredMeter("les/server/req/avgServedTime", nil)
requestServedTimer = metrics.NewRegisteredTimer("les/server/req/servedTime", nil)

View File

@ -149,7 +149,7 @@ func NewLesServer(node *node.Node, e ethBackend, config *ethconfig.Config) (*Les
srv.maxCapacity = totalRecharge
}
srv.fcManager.SetCapacityLimits(srv.minCapacity, srv.maxCapacity, srv.minCapacity*2)
srv.clientPool = newClientPool(ns, lesDb, srv.minCapacity, defaultConnectedBias, mclock.System{}, srv.dropClient)
srv.clientPool = newClientPool(ns, lesDb, srv.minCapacity, defaultConnectedBias, mclock.System{}, srv.dropClient, issync)
srv.clientPool.setDefaultFactors(vfs.PriceFactors{TimeFactor: 0, CapacityFactor: 1, RequestFactor: 1}, vfs.PriceFactors{TimeFactor: 0, CapacityFactor: 1, RequestFactor: 1})
checkpoint := srv.latestLocalCheckpoint()

View File

@ -307,7 +307,7 @@ func newTestServerHandler(blocks int, indexers []*core.ChainIndexer, db ethdb.Da
}
server.costTracker, server.minCapacity = newCostTracker(db, server.config)
server.costTracker.testCostList = testCostList(0) // Disable flow control mechanism.
server.clientPool = newClientPool(ns, db, testBufRecharge, defaultConnectedBias, clock, func(id enode.ID) {})
server.clientPool = newClientPool(ns, db, testBufRecharge, defaultConnectedBias, clock, func(id enode.ID) {}, alwaysTrueFn)
server.clientPool.setLimits(10000, 10000) // Assign enough capacity for clientpool
server.handler = newServerHandler(server, simulation.Blockchain(), db, txpool, func() bool { return true })
if server.oracle != nil {
@ -319,6 +319,10 @@ func newTestServerHandler(blocks int, indexers []*core.ChainIndexer, db ethdb.Da
return server.handler, simulation
}
func alwaysTrueFn() bool {
return true
}
// testPeer is a simulated peer to allow testing direct network calls.
type testPeer struct {
cpeer *clientPeer

View File

@ -47,7 +47,8 @@ const (
nodeWeightThreshold = 100 // minimum weight for keeping a node in the the known (valuable) set
minRedialWait = 10 // minimum redial wait time in seconds
preNegLimit = 5 // maximum number of simultaneous pre-negotiation queries
maxQueryFails = 100 // number of consecutive UDP query failures before we print a warning
warnQueryFails = 20 // number of consecutive UDP query failures before we print a warning
maxQueryFails = 100 // number of consecutive UDP query failures when then chance of skipping a query reaches 50%
)
// ServerPool provides a node iterator for dial candidates. The output is a mix of newly discovered
@ -94,16 +95,16 @@ type nodeHistoryEnc struct {
type QueryFunc func(*enode.Node) int
var (
clientSetup = &nodestate.Setup{Version: 2}
sfHasValue = clientSetup.NewPersistentFlag("hasValue")
sfQueried = clientSetup.NewFlag("queried")
sfCanDial = clientSetup.NewFlag("canDial")
sfDialing = clientSetup.NewFlag("dialed")
sfWaitDialTimeout = clientSetup.NewFlag("dialTimeout")
sfConnected = clientSetup.NewFlag("connected")
sfRedialWait = clientSetup.NewFlag("redialWait")
sfAlwaysConnect = clientSetup.NewFlag("alwaysConnect")
sfDisableSelection = nodestate.MergeFlags(sfQueried, sfCanDial, sfDialing, sfConnected, sfRedialWait)
clientSetup = &nodestate.Setup{Version: 2}
sfHasValue = clientSetup.NewPersistentFlag("hasValue")
sfQuery = clientSetup.NewFlag("query")
sfCanDial = clientSetup.NewFlag("canDial")
sfDialing = clientSetup.NewFlag("dialed")
sfWaitDialTimeout = clientSetup.NewFlag("dialTimeout")
sfConnected = clientSetup.NewFlag("connected")
sfRedialWait = clientSetup.NewFlag("redialWait")
sfAlwaysConnect = clientSetup.NewFlag("alwaysConnect")
sfDialProcess = nodestate.MergeFlags(sfQuery, sfCanDial, sfDialing, sfConnected, sfRedialWait)
sfiNodeHistory = clientSetup.NewPersistentField("nodeHistory", reflect.TypeOf(nodeHistory{}),
func(field interface{}) ([]byte, error) {
@ -162,8 +163,8 @@ func NewServerPool(db ethdb.KeyValueStore, dbKey []byte, mixTimeout time.Duratio
}
s.recalTimeout()
s.mixer = enode.NewFairMix(mixTimeout)
knownSelector := NewWrsIterator(s.ns, sfHasValue, sfDisableSelection, sfiNodeWeight)
alwaysConnect := NewQueueIterator(s.ns, sfAlwaysConnect, sfDisableSelection, true, nil)
knownSelector := NewWrsIterator(s.ns, sfHasValue, sfDialProcess, sfiNodeWeight)
alwaysConnect := NewQueueIterator(s.ns, sfAlwaysConnect, sfDialProcess, true, nil)
s.mixSources = append(s.mixSources, knownSelector)
s.mixSources = append(s.mixSources, alwaysConnect)
@ -226,7 +227,7 @@ func (s *ServerPool) AddMetrics(
s.totalValueGauge = totalValueGauge
s.sessionValueMeter = sessionValueMeter
if serverSelectableGauge != nil {
s.ns.AddLogMetrics(sfHasValue, sfDisableSelection, "selectable", nil, nil, serverSelectableGauge)
s.ns.AddLogMetrics(sfHasValue, sfDialProcess, "selectable", nil, nil, serverSelectableGauge)
}
if serverDialedMeter != nil {
s.ns.AddLogMetrics(sfDialing, nodestate.Flags{}, "dialed", serverDialedMeter, nil, nil)
@ -247,43 +248,51 @@ func (s *ServerPool) AddSource(source enode.Iterator) {
// Nodes that are filtered out and does not appear on the output iterator are put back
// into redialWait state.
func (s *ServerPool) addPreNegFilter(input enode.Iterator, query QueryFunc) enode.Iterator {
s.fillSet = NewFillSet(s.ns, input, sfQueried)
s.ns.SubscribeState(sfQueried, func(n *enode.Node, oldState, newState nodestate.Flags) {
if newState.Equals(sfQueried) {
fails := atomic.LoadUint32(&s.queryFails)
if fails == maxQueryFails {
log.Warn("UDP pre-negotiation query does not seem to work")
s.fillSet = NewFillSet(s.ns, input, sfQuery)
s.ns.SubscribeState(sfDialProcess, func(n *enode.Node, oldState, newState nodestate.Flags) {
if !newState.Equals(sfQuery) {
if newState.HasAll(sfQuery) {
// remove query flag if the node is already somewhere in the dial process
s.ns.SetStateSub(n, nodestate.Flags{}, sfQuery, 0)
}
if fails > maxQueryFails {
fails = maxQueryFails
}
if rand.Intn(maxQueryFails*2) < int(fails) {
// skip pre-negotiation with increasing chance, max 50%
// this ensures that the client can operate even if UDP is not working at all
s.ns.SetStateSub(n, sfCanDial, nodestate.Flags{}, time.Second*10)
// set canDial before resetting queried so that FillSet will not read more
// candidates unnecessarily
s.ns.SetStateSub(n, nodestate.Flags{}, sfQueried, 0)
return
}
go func() {
q := query(n)
if q == -1 {
atomic.AddUint32(&s.queryFails, 1)
} else {
atomic.StoreUint32(&s.queryFails, 0)
}
s.ns.Operation(func() {
// we are no longer running in the operation that the callback belongs to, start a new one because of setRedialWait
if q == 1 {
s.ns.SetStateSub(n, sfCanDial, nodestate.Flags{}, time.Second*10)
} else {
s.setRedialWait(n, queryCost, queryWaitStep)
}
s.ns.SetStateSub(n, nodestate.Flags{}, sfQueried, 0)
})
}()
return
}
fails := atomic.LoadUint32(&s.queryFails)
failMax := fails
if failMax > maxQueryFails {
failMax = maxQueryFails
}
if rand.Intn(maxQueryFails*2) < int(failMax) {
// skip pre-negotiation with increasing chance, max 50%
// this ensures that the client can operate even if UDP is not working at all
s.ns.SetStateSub(n, sfCanDial, nodestate.Flags{}, time.Second*10)
// set canDial before resetting queried so that FillSet will not read more
// candidates unnecessarily
s.ns.SetStateSub(n, nodestate.Flags{}, sfQuery, 0)
return
}
go func() {
q := query(n)
if q == -1 {
atomic.AddUint32(&s.queryFails, 1)
fails++
if fails%warnQueryFails == 0 {
// warn if a large number of consecutive queries have failed
log.Warn("UDP connection queries failed", "count", fails)
}
} else {
atomic.StoreUint32(&s.queryFails, 0)
}
s.ns.Operation(func() {
// we are no longer running in the operation that the callback belongs to, start a new one because of setRedialWait
if q == 1 {
s.ns.SetStateSub(n, sfCanDial, nodestate.Flags{}, time.Second*10)
} else {
s.setRedialWait(n, queryCost, queryWaitStep)
}
s.ns.SetStateSub(n, nodestate.Flags{}, sfQuery, 0)
})
}()
})
return NewQueueIterator(s.ns, sfCanDial, nodestate.Flags{}, false, func(waiting bool) {
if waiting {