bsc/les/freeclient_test.go
Felföldi Zsolt c2003ed63b les, les/flowcontrol: improved request serving and flow control (#18230)
This change

- implements concurrent LES request serving even for a single peer.
- replaces the request cost estimation method with a cost table based on
  benchmarks which gives much more consistent results. Until now the
  allowed number of light peers was just a guess which probably contributed
  a lot to the fluctuating quality of available service. Everything related
  to request cost is implemented in a single object, the 'cost tracker'. It
  uses a fixed cost table with a global 'correction factor'. Benchmark code
  is included and can be run at any time to adapt costs to low-level
  implementation changes.
- reimplements flowcontrol.ClientManager in a cleaner and more efficient
  way, with added capabilities: There is now control over bandwidth, which
  allows using the flow control parameters for client prioritization.
  Target utilization over 100 percent is now supported to model concurrent
  request processing. Total serving bandwidth is reduced during block
  processing to prevent database contention.
- implements an RPC API for the LES servers allowing server operators to
  assign priority bandwidth to certain clients and change prioritized
  status even while the client is connected. The new API is meant for
  cases where server operators charge for LES using an off-protocol mechanism.
- adds a unit test for the new client manager.
- adds an end-to-end test using the network simulator that tests bandwidth
  control functions through the new API.
2019-02-26 12:32:48 +01:00

146 lines
4.1 KiB
Go

// Copyright 2017 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 (
"fmt"
"math/rand"
"strconv"
"testing"
"time"
"github.com/ethereum/go-ethereum/common/mclock"
"github.com/ethereum/go-ethereum/ethdb"
)
func TestFreeClientPoolL10C100(t *testing.T) {
testFreeClientPool(t, 10, 100)
}
func TestFreeClientPoolL40C200(t *testing.T) {
testFreeClientPool(t, 40, 200)
}
func TestFreeClientPoolL100C300(t *testing.T) {
testFreeClientPool(t, 100, 300)
}
const testFreeClientPoolTicks = 500000
func testFreeClientPool(t *testing.T, connLimit, clientCount int) {
var (
clock mclock.Simulated
db = ethdb.NewMemDatabase()
connected = make([]bool, clientCount)
connTicks = make([]int, clientCount)
disconnCh = make(chan int, clientCount)
peerAddress = func(i int) string {
return fmt.Sprintf("addr #%d", i)
}
peerId = func(i int) string {
return fmt.Sprintf("id #%d", i)
}
disconnFn = func(id string) {
i, err := strconv.Atoi(id[4:])
if err != nil {
panic(err)
}
disconnCh <- i
}
pool = newFreeClientPool(db, 1, 10000, &clock, disconnFn)
)
pool.setLimits(connLimit, uint64(connLimit))
// pool should accept new peers up to its connected limit
for i := 0; i < connLimit; i++ {
if pool.connect(peerAddress(i), peerId(i)) {
connected[i] = true
} else {
t.Fatalf("Test peer #%d rejected", i)
}
}
// since all accepted peers are new and should not be kicked out, the next one should be rejected
if pool.connect(peerAddress(connLimit), peerId(connLimit)) {
connected[connLimit] = true
t.Fatalf("Peer accepted over connected limit")
}
// randomly connect and disconnect peers, expect to have a similar total connection time at the end
for tickCounter := 0; tickCounter < testFreeClientPoolTicks; tickCounter++ {
clock.Run(1 * time.Second)
i := rand.Intn(clientCount)
if connected[i] {
pool.disconnect(peerAddress(i))
connected[i] = false
connTicks[i] += tickCounter
} else {
if pool.connect(peerAddress(i), peerId(i)) {
connected[i] = true
connTicks[i] -= tickCounter
}
}
pollDisconnects:
for {
select {
case i := <-disconnCh:
pool.disconnect(peerAddress(i))
if connected[i] {
connTicks[i] += tickCounter
connected[i] = false
}
default:
break pollDisconnects
}
}
}
expTicks := testFreeClientPoolTicks * connLimit / clientCount
expMin := expTicks - expTicks/10
expMax := expTicks + expTicks/10
// check if the total connected time of peers are all in the expected range
for i, c := range connected {
if c {
connTicks[i] += testFreeClientPoolTicks
}
if connTicks[i] < expMin || connTicks[i] > expMax {
t.Errorf("Total connected time of test node #%d (%d) outside expected range (%d to %d)", i, connTicks[i], expMin, expMax)
}
}
// a previously unknown peer should be accepted now
if !pool.connect("newAddr", "newId") {
t.Fatalf("Previously unknown peer rejected")
}
// close and restart pool
pool.stop()
pool = newFreeClientPool(db, 1, 10000, &clock, disconnFn)
pool.setLimits(connLimit, uint64(connLimit))
// try connecting all known peers (connLimit should be filled up)
for i := 0; i < clientCount; i++ {
pool.connect(peerAddress(i), peerId(i))
}
// expect pool to remember known nodes and kick out one of them to accept a new one
if !pool.connect("newAddr2", "newId2") {
t.Errorf("Previously unknown peer rejected after restarting pool")
}
pool.stop()
}