plugeth/les/server.go
Felföldi Zsolt b4a2681120
les, les/lespay: implement new server pool (#20758)
This PR reimplements the light client server pool. It is also a first step
to move certain logic into a new lespay package. This package will contain
the implementation of the lespay token sale functions, the token buying and
selling logic and other components related to peer selection/prioritization
and service quality evaluation. Over the long term this package will be
reusable for incentivizing future protocols.

Since the LES peer logic is now based on enode.Iterator, it can now use
DNS-based fallback discovery to find servers.

This document describes the function of the new components:
https://gist.github.com/zsfelfoldi/3c7ace895234b7b345ab4f71dab102d4
2020-05-22 13:46:34 +02:00

282 lines
9.3 KiB
Go

// Copyright 2016 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package les
import (
"crypto/ecdsa"
"time"
"github.com/ethereum/go-ethereum/accounts/abi/bind"
"github.com/ethereum/go-ethereum/common/mclock"
"github.com/ethereum/go-ethereum/core"
"github.com/ethereum/go-ethereum/eth"
"github.com/ethereum/go-ethereum/les/checkpointoracle"
"github.com/ethereum/go-ethereum/les/flowcontrol"
"github.com/ethereum/go-ethereum/light"
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/p2p"
"github.com/ethereum/go-ethereum/p2p/discv5"
"github.com/ethereum/go-ethereum/p2p/enode"
"github.com/ethereum/go-ethereum/p2p/enr"
"github.com/ethereum/go-ethereum/params"
"github.com/ethereum/go-ethereum/rpc"
)
type LesServer struct {
lesCommons
archiveMode bool // Flag whether the ethereum node runs in archive mode.
peers *clientPeerSet
handler *serverHandler
lesTopics []discv5.Topic
privateKey *ecdsa.PrivateKey
// Flow control and capacity management
fcManager *flowcontrol.ClientManager
costTracker *costTracker
defParams flowcontrol.ServerParams
servingQueue *servingQueue
clientPool *clientPool
minCapacity, maxCapacity, freeCapacity uint64
threadsIdle int // Request serving threads count when system is idle.
threadsBusy int // Request serving threads count when system is busy(block insertion).
}
func NewLesServer(e *eth.Ethereum, config *eth.Config) (*LesServer, error) {
// Collect les protocol version information supported by local node.
lesTopics := make([]discv5.Topic, len(AdvertiseProtocolVersions))
for i, pv := range AdvertiseProtocolVersions {
lesTopics[i] = lesTopic(e.BlockChain().Genesis().Hash(), pv)
}
// Calculate the number of threads used to service the light client
// requests based on the user-specified value.
threads := config.LightServ * 4 / 100
if threads < 4 {
threads = 4
}
srv := &LesServer{
lesCommons: lesCommons{
genesis: e.BlockChain().Genesis().Hash(),
config: config,
chainConfig: e.BlockChain().Config(),
iConfig: light.DefaultServerIndexerConfig,
chainDb: e.ChainDb(),
chainReader: e.BlockChain(),
chtIndexer: light.NewChtIndexer(e.ChainDb(), nil, params.CHTFrequency, params.HelperTrieProcessConfirmations),
bloomTrieIndexer: light.NewBloomTrieIndexer(e.ChainDb(), nil, params.BloomBitsBlocks, params.BloomTrieFrequency),
closeCh: make(chan struct{}),
},
archiveMode: e.ArchiveMode(),
peers: newClientPeerSet(),
lesTopics: lesTopics,
fcManager: flowcontrol.NewClientManager(nil, &mclock.System{}),
servingQueue: newServingQueue(int64(time.Millisecond*10), float64(config.LightServ)/100),
threadsBusy: config.LightServ/100 + 1,
threadsIdle: threads,
}
srv.handler = newServerHandler(srv, e.BlockChain(), e.ChainDb(), e.TxPool(), e.Synced)
srv.costTracker, srv.minCapacity = newCostTracker(e.ChainDb(), config)
srv.freeCapacity = srv.minCapacity
// Set up checkpoint oracle.
oracle := config.CheckpointOracle
if oracle == nil {
oracle = params.CheckpointOracles[e.BlockChain().Genesis().Hash()]
}
srv.oracle = checkpointoracle.New(oracle, srv.localCheckpoint)
// Initialize server capacity management fields.
srv.defParams = flowcontrol.ServerParams{
BufLimit: srv.freeCapacity * bufLimitRatio,
MinRecharge: srv.freeCapacity,
}
// LES flow control tries to more or less guarantee the possibility for the
// clients to send a certain amount of requests at any time and get a quick
// response. Most of the clients want this guarantee but don't actually need
// to send requests most of the time. Our goal is to serve as many clients as
// possible while the actually used server capacity does not exceed the limits
totalRecharge := srv.costTracker.totalRecharge()
srv.maxCapacity = srv.freeCapacity * uint64(srv.config.LightPeers)
if totalRecharge > srv.maxCapacity {
srv.maxCapacity = totalRecharge
}
srv.fcManager.SetCapacityLimits(srv.freeCapacity, srv.maxCapacity, srv.freeCapacity*2)
srv.clientPool = newClientPool(srv.chainDb, srv.freeCapacity, mclock.System{}, func(id enode.ID) { go srv.peers.unregister(peerIdToString(id)) })
srv.clientPool.setDefaultFactors(priceFactors{0, 1, 1}, priceFactors{0, 1, 1})
checkpoint := srv.latestLocalCheckpoint()
if !checkpoint.Empty() {
log.Info("Loaded latest checkpoint", "section", checkpoint.SectionIndex, "head", checkpoint.SectionHead,
"chtroot", checkpoint.CHTRoot, "bloomroot", checkpoint.BloomRoot)
}
srv.chtIndexer.Start(e.BlockChain())
return srv, nil
}
func (s *LesServer) APIs() []rpc.API {
return []rpc.API{
{
Namespace: "les",
Version: "1.0",
Service: NewPrivateLightAPI(&s.lesCommons),
Public: false,
},
{
Namespace: "les",
Version: "1.0",
Service: NewPrivateLightServerAPI(s),
Public: false,
},
{
Namespace: "debug",
Version: "1.0",
Service: NewPrivateDebugAPI(s),
Public: false,
},
}
}
func (s *LesServer) Protocols() []p2p.Protocol {
ps := s.makeProtocols(ServerProtocolVersions, s.handler.runPeer, func(id enode.ID) interface{} {
if p := s.peers.peer(peerIdToString(id)); p != nil {
return p.Info()
}
return nil
}, nil)
// Add "les" ENR entries.
for i := range ps {
ps[i].Attributes = []enr.Entry{&lesEntry{}}
}
return ps
}
// Start starts the LES server
func (s *LesServer) Start(srvr *p2p.Server) {
s.privateKey = srvr.PrivateKey
s.handler.start()
s.wg.Add(1)
go s.capacityManagement()
if srvr.DiscV5 != nil {
for _, topic := range s.lesTopics {
topic := topic
go func() {
logger := log.New("topic", topic)
logger.Info("Starting topic registration")
defer logger.Info("Terminated topic registration")
srvr.DiscV5.RegisterTopic(topic, s.closeCh)
}()
}
}
}
// Stop stops the LES service
func (s *LesServer) Stop() {
close(s.closeCh)
// Disconnect existing sessions.
// This also closes the gate for any new registrations on the peer set.
// sessions which are already established but not added to pm.peers yet
// will exit when they try to register.
s.peers.close()
s.fcManager.Stop()
s.costTracker.stop()
s.handler.stop()
s.clientPool.stop() // client pool should be closed after handler.
s.servingQueue.stop()
// Note, bloom trie indexer is closed by parent bloombits indexer.
s.chtIndexer.Close()
s.wg.Wait()
log.Info("Les server stopped")
}
func (s *LesServer) SetBloomBitsIndexer(bloomIndexer *core.ChainIndexer) {
bloomIndexer.AddChildIndexer(s.bloomTrieIndexer)
}
// SetClient sets the rpc client and starts running checkpoint contract if it is not yet watched.
func (s *LesServer) SetContractBackend(backend bind.ContractBackend) {
if s.oracle == nil {
return
}
s.oracle.Start(backend)
}
// capacityManagement starts an event handler loop that updates the recharge curve of
// the client manager and adjusts the client pool's size according to the total
// capacity updates coming from the client manager
func (s *LesServer) capacityManagement() {
defer s.wg.Done()
processCh := make(chan bool, 100)
sub := s.handler.blockchain.SubscribeBlockProcessingEvent(processCh)
defer sub.Unsubscribe()
totalRechargeCh := make(chan uint64, 100)
totalRecharge := s.costTracker.subscribeTotalRecharge(totalRechargeCh)
totalCapacityCh := make(chan uint64, 100)
totalCapacity := s.fcManager.SubscribeTotalCapacity(totalCapacityCh)
s.clientPool.setLimits(s.config.LightPeers, totalCapacity)
var (
busy bool
freePeers uint64
blockProcess mclock.AbsTime
)
updateRecharge := func() {
if busy {
s.servingQueue.setThreads(s.threadsBusy)
s.fcManager.SetRechargeCurve(flowcontrol.PieceWiseLinear{{0, 0}, {totalRecharge, totalRecharge}})
} else {
s.servingQueue.setThreads(s.threadsIdle)
s.fcManager.SetRechargeCurve(flowcontrol.PieceWiseLinear{{0, 0}, {totalRecharge / 10, totalRecharge}, {totalRecharge, totalRecharge}})
}
}
updateRecharge()
for {
select {
case busy = <-processCh:
if busy {
blockProcess = mclock.Now()
} else {
blockProcessingTimer.Update(time.Duration(mclock.Now() - blockProcess))
}
updateRecharge()
case totalRecharge = <-totalRechargeCh:
totalRechargeGauge.Update(int64(totalRecharge))
updateRecharge()
case totalCapacity = <-totalCapacityCh:
totalCapacityGauge.Update(int64(totalCapacity))
newFreePeers := totalCapacity / s.freeCapacity
if newFreePeers < freePeers && newFreePeers < uint64(s.config.LightPeers) {
log.Warn("Reduced free peer connections", "from", freePeers, "to", newFreePeers)
}
freePeers = newFreePeers
s.clientPool.setLimits(s.config.LightPeers, totalCapacity)
case <-s.closeCh:
return
}
}
}