forked from hashicorp/raft
/
cluster.go
388 lines (363 loc) · 10.6 KB
/
cluster.go
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package fuzzy
import (
"bytes"
"fmt"
"io"
"io/ioutil"
"log"
"os"
"path/filepath"
"testing"
"time"
"github.com/hashicorp/raft"
)
type appliedItem struct {
index uint64
data []byte
}
type cluster struct {
nodes []*raftNode
removedNodes []*raftNode
lastApplySuccess raft.ApplyFuture
lastApplyFailure raft.ApplyFuture
applied []appliedItem
log Logger
transports *transports
hooks TransportHooks
}
// Logger is abstract type for debug log messages
type Logger interface {
Log(v ...interface{})
Logf(s string, v ...interface{})
}
// LoggerAdapter allows a log.Logger to be used with the local Logger interface
type LoggerAdapter struct {
log *log.Logger
}
// Log a message to the contained debug log
func (a *LoggerAdapter) Log(v ...interface{}) {
a.log.Print(v...)
}
// Logf will record a formatted message to the contained debug log
func (a *LoggerAdapter) Logf(s string, v ...interface{}) {
a.log.Printf(s, v...)
}
func newRaftCluster(t *testing.T, logWriter io.Writer, namePrefix string, n uint, transportHooks TransportHooks) *cluster {
res := make([]*raftNode, 0, n)
names := make([]string, 0, n)
for i := uint(0); i < n; i++ {
names = append(names, nodeName(namePrefix, i))
}
l := log.New(logWriter, "", log.Lmicroseconds)
transports := newTransports(l)
for _, i := range names {
r, err := newRaftNode(log.New(logWriter, i+":", log.Lmicroseconds), transports, transportHooks, names, i)
if err != nil {
t.Fatalf("Unable to create raftNode:%v : %v", i, err)
}
res = append(res, r)
}
return &cluster{
nodes: res,
removedNodes: make([]*raftNode, 0, n),
applied: make([]appliedItem, 0, 1024),
log: &LoggerAdapter{l},
transports: transports,
hooks: transportHooks,
}
}
func (c *cluster) CreateAndAddNode(t *testing.T, logWriter io.Writer, namePrefix string, nodeNum uint) error {
name := nodeName(namePrefix, nodeNum)
rn, err := newRaftNode(log.New(logWriter, name+":", log.Lmicroseconds), c.transports, c.hooks, nil, name)
if err != nil {
t.Fatalf("Unable to create raftNode:%v : %v", name, err)
}
c.nodes = append(c.nodes, rn)
f := c.Leader(time.Minute).raft.AddVoter(raft.ServerID(name), raft.ServerAddress(name), 0, 0)
return f.Error()
}
func nodeName(prefix string, num uint) string {
return fmt.Sprintf("%v_%d", prefix, num)
}
func (c *cluster) RemoveNode(t *testing.T, name string) *raftNode {
nc := make([]*raftNode, 0, len(c.nodes))
var nodeToRemove *raftNode
for _, rn := range c.nodes {
if rn.name == name {
nodeToRemove = rn
} else {
nc = append(nc, rn)
}
}
if nodeToRemove == nil {
t.Fatalf("Unable to find node with name '%v' in cluster", name)
}
c.log.Logf("Removing node %v from cluster", name)
c.Leader(time.Minute).raft.RemovePeer(raft.ServerAddress(name)).Error()
c.nodes = nc
c.removedNodes = append(c.removedNodes, nodeToRemove)
return nodeToRemove
}
// Leader returns the node that is currently the Leader, if there is no
// leader this function blocks until a leader is elected (or a timeout occurs)
func (c *cluster) Leader(timeout time.Duration) *raftNode {
start := time.Now()
for true {
for _, n := range c.nodes {
if n.raft.State() == raft.Leader {
return n
}
}
if time.Now().Sub(start) > timeout {
return nil
}
time.Sleep(time.Millisecond)
}
return nil
}
// containsNode returns true if the slice 'nodes' contains 'n'
func containsNode(nodes []*raftNode, n *raftNode) bool {
for _, rn := range nodes {
if rn == n {
return true
}
}
return false
}
// LeaderPlus returns the leader + n additional nodes from the cluster
// the leader is always the first node in the returned slice.
func (c *cluster) LeaderPlus(n int) []*raftNode {
r := make([]*raftNode, 0, n+1)
ldr := c.Leader(time.Second)
if ldr != nil {
r = append(r, ldr)
}
if len(r) >= n {
return r
}
for _, node := range c.nodes {
if !containsNode(r, node) {
r = append(r, node)
if len(r) >= n {
return r
}
}
}
return r
}
func (c *cluster) Stop(t *testing.T, maxWait time.Duration) {
c.WaitTilUptoDate(t, maxWait)
for _, n := range c.nodes {
n.raft.Shutdown()
}
}
// WaitTilUptoDate blocks until all nodes in the cluster have gotten their
// commitedIndex upto the Index from the last successful call to Apply
func (c *cluster) WaitTilUptoDate(t *testing.T, maxWait time.Duration) {
idx := c.lastApplySuccess.Index()
start := time.Now()
for true {
allAtIdx := true
for i := 0; i < len(c.nodes); i++ {
nodeAppliedIdx := c.nodes[i].raft.AppliedIndex()
if nodeAppliedIdx < idx {
allAtIdx = false
break
} else if nodeAppliedIdx > idx {
allAtIdx = false
idx = nodeAppliedIdx
break
}
}
if allAtIdx {
t.Logf("All nodes have appliedIndex=%d", idx)
return
}
if time.Now().Sub(start) > maxWait {
t.Fatalf("Gave up waiting for all nodes to reach raft Index %d, [currently at %v]", idx, c.appliedIndexes())
}
time.Sleep(time.Millisecond * 10)
}
}
func (c *cluster) appliedIndexes() map[string]uint64 {
r := make(map[string]uint64, len(c.nodes))
for _, n := range c.nodes {
r[n.name] = n.raft.AppliedIndex()
}
return r
}
func (c *cluster) ApplyN(t *testing.T, leaderTimeout time.Duration, s *applySource, n uint) uint64 {
f := make([]raft.ApplyFuture, n)
data := make([][]byte, n)
startTime := time.Now()
endTime := startTime.Add(leaderTimeout)
for i := uint(0); i < n; i++ {
ldr := c.Leader(endTime.Sub(time.Now()))
if ldr != nil {
data[i] = s.nextEntry()
f[i] = ldr.raft.Apply(data[i], time.Second)
}
}
success := uint64(0)
for i := uint(0); i < n; i++ {
if f[i] == nil {
continue
}
if err := f[i].Error(); err == nil {
success++
c.lastApplySuccess = f[i]
c.applied = append(c.applied, appliedItem{f[i].Index(), data[i]})
} else {
c.lastApplyFailure = f[i]
}
}
return success
}
func (c *cluster) VerifyFSM(t *testing.T) {
exp := c.nodes[0].fsm
expName := c.nodes[0].name
for i, n := range c.nodes {
if i > 0 {
if exp.lastIndex != n.fsm.lastIndex {
t.Errorf("Node %v FSM lastIndex is %d, but Node %v FSM lastIndex is %d", n.name, n.fsm.lastIndex, expName, exp.lastIndex)
}
if exp.lastTerm != n.fsm.lastTerm {
t.Errorf("Node %v FSM lastTerm is %d, but Node %v FSM lastTerm is %d", n.name, n.fsm.lastTerm, expName, exp.lastTerm)
}
if !bytes.Equal(exp.lastHash, n.fsm.lastHash) {
t.Errorf("Node %v FSM lastHash is %v, but Node %v FSM lastHash is %v", n.name, n.fsm.lastHash, expName, exp.lastHash)
}
}
t.Logf("node %v final FSM hash is %v", n.name, n.fsm.lastHash)
}
if t.Failed() {
c.RecordState(t)
}
}
func (c *cluster) RecordState(t *testing.T) {
td, _ := ioutil.TempDir(os.Getenv("TEST_FAIL_DIR"), "failure")
sd, _ := resolveDirectory("data", false)
copyDir(td, sd)
dump := func(n *raftNode) {
nt := filepath.Join(td, n.name)
os.Mkdir(nt, 0777)
n.fsm.WriteTo(filepath.Join(nt, "fsm.txt"))
n.transport.DumpLog(nt)
}
for _, n := range c.nodes {
dump(n)
}
for _, n := range c.removedNodes {
dump(n)
}
fmt.Printf("State of failing cluster captured in %v", td)
}
func copyDir(target, src string) {
filepath.Walk(src, func(path string, info os.FileInfo, err error) error {
relPath := path[len(src):]
if info.IsDir() {
return os.MkdirAll(filepath.Join(target, relPath), 0777)
}
return copyFile(filepath.Join(target, relPath), path)
})
}
func copyFile(target, src string) error {
r, err := os.Open(src)
if err != nil {
return err
}
defer r.Close()
w, err := os.Create(target)
if err != nil {
return err
}
defer w.Close()
_, err = io.Copy(w, r)
return err
}
func (c *cluster) VerifyLog(t *testing.T, applyCount uint64) {
fi, _ := c.nodes[0].store.FirstIndex()
li, _ := c.nodes[0].store.LastIndex()
name := c.nodes[0].name
for _, n := range c.nodes {
nfi, err := n.store.FirstIndex()
if err != nil {
t.Errorf("Failed to get FirstIndex of log for node %v: %v", n.name, err)
continue
}
if nfi != fi {
t.Errorf("Node %v has FirstIndex of %d but node %v has %d", n.name, nfi, name, fi)
}
nli, err := n.store.LastIndex()
if err != nil {
t.Errorf("Failed to get LastIndex of log for node %v: %v", n.name, err)
continue
}
if nli != li {
t.Errorf("Node %v has LastIndex of %d, but node %v has %d", n.name, nli, name, li)
}
if nli-nfi < applyCount {
t.Errorf("Node %v Log contains %d entries, but should contain at least %d", n.name, nli-nfi, applyCount)
continue
}
var term uint64
for i := fi; i <= li; i++ {
var nEntry raft.Log
var n0Entry raft.Log
if err := c.nodes[0].store.GetLog(i, &n0Entry); err != nil {
t.Errorf("Failed to log entry %d on node %v: %v", i, name, err)
continue
}
if err := n.store.GetLog(i, &nEntry); err != nil {
t.Errorf("Failed to log entry at log Index %d on node %v: %v", i, n.name, err)
continue
}
if i != nEntry.Index {
t.Errorf("Asked for Log Index %d from Store on node %v, but got index %d instead", i, n.name, nEntry.Index)
}
if i == fi {
term = nEntry.Term
} else {
if nEntry.Term < term {
t.Errorf("Node %v, Prior Log Entry was for term %d, but this log entry is for term %d, terms shouldn't go backwards", n.name, term, nEntry.Term)
}
}
term = nEntry.Term
assertLogEntryEqual(t, n.name, &n0Entry, &nEntry)
}
// the above checks the logs between the nodes, also check that the log
// contains the items that Apply returned success for.
var entry raft.Log
for _, ai := range c.applied {
err := n.store.GetLog(ai.index, &entry)
if err != nil {
t.Errorf("Failed to fetch logIndex %d on node %v: %v", ai.index, n.name, err)
}
if !bytes.Equal(ai.data, entry.Data) {
t.Errorf("Client applied %v at index %d, but log for node %v contains %d", ai.data, ai.index, n.name, entry.Data)
}
}
}
}
// assertLogEntryEqual compares the 2 raft Log entries and reports any differences to the supplied testing.T instance
// it return true if the 2 entries are equal, false otherwise.
func assertLogEntryEqual(t *testing.T, node string, exp *raft.Log, act *raft.Log) bool {
res := true
if exp.Term != act.Term {
t.Errorf("Log Entry at Index %d for node %v has mismatched terms %d/%d", exp.Index, node, exp.Term, act.Term)
res = false
}
if exp.Index != act.Index {
t.Errorf("Node %v, Log Entry should be Index %d,but is %d", node, exp.Index, act.Index)
res = false
}
if exp.Type != act.Type {
t.Errorf("Node %v, Log Entry at Index %d should have type %v but is %v", node, exp.Index, exp.Type, act.Type)
res = false
}
if !bytes.Equal(exp.Data, act.Data) {
t.Errorf("Node %v, Log Entry at Index %d should have data %v, but has %v", node, exp.Index, exp.Data, act.Data)
res = false
}
return res
}