k3s/vendor/go.etcd.io/etcd/etcdserver/api/membership/cluster.go

842 lines
22 KiB
Go

// Copyright 2015 The etcd Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package membership
import (
"bytes"
"context"
"crypto/sha1"
"encoding/binary"
"encoding/json"
"fmt"
"path"
"sort"
"strings"
"sync"
"time"
"go.etcd.io/etcd/etcdserver/api/v2store"
"go.etcd.io/etcd/mvcc/backend"
"go.etcd.io/etcd/pkg/netutil"
"go.etcd.io/etcd/pkg/types"
"go.etcd.io/etcd/raft"
"go.etcd.io/etcd/raft/raftpb"
"go.etcd.io/etcd/version"
"github.com/coreos/go-semver/semver"
"github.com/prometheus/client_golang/prometheus"
"go.uber.org/zap"
)
const maxLearners = 1
// RaftCluster is a list of Members that belong to the same raft cluster
type RaftCluster struct {
lg *zap.Logger
localID types.ID
cid types.ID
token string
v2store v2store.Store
be backend.Backend
sync.Mutex // guards the fields below
version *semver.Version
members map[types.ID]*Member
// removed contains the ids of removed members in the cluster.
// removed id cannot be reused.
removed map[types.ID]bool
}
// ConfigChangeContext represents a context for confChange.
type ConfigChangeContext struct {
Member
// IsPromote indicates if the config change is for promoting a learner member.
// This flag is needed because both adding a new member and promoting a learner member
// uses the same config change type 'ConfChangeAddNode'.
IsPromote bool `json:"isPromote"`
}
// NewClusterFromURLsMap creates a new raft cluster using provided urls map. Currently, it does not support creating
// cluster with raft learner member.
func NewClusterFromURLsMap(lg *zap.Logger, token string, urlsmap types.URLsMap) (*RaftCluster, error) {
c := NewCluster(lg, token)
for name, urls := range urlsmap {
m := NewMember(name, urls, token, nil)
if _, ok := c.members[m.ID]; ok {
return nil, fmt.Errorf("member exists with identical ID %v", m)
}
if uint64(m.ID) == raft.None {
return nil, fmt.Errorf("cannot use %x as member id", raft.None)
}
c.members[m.ID] = m
}
c.genID()
return c, nil
}
func NewClusterFromMembers(lg *zap.Logger, token string, id types.ID, membs []*Member) *RaftCluster {
c := NewCluster(lg, token)
c.cid = id
for _, m := range membs {
c.members[m.ID] = m
}
return c
}
func NewCluster(lg *zap.Logger, token string) *RaftCluster {
return &RaftCluster{
lg: lg,
token: token,
members: make(map[types.ID]*Member),
removed: make(map[types.ID]bool),
}
}
func (c *RaftCluster) ID() types.ID { return c.cid }
func (c *RaftCluster) Members() []*Member {
c.Lock()
defer c.Unlock()
var ms MembersByID
for _, m := range c.members {
ms = append(ms, m.Clone())
}
sort.Sort(ms)
return []*Member(ms)
}
func (c *RaftCluster) Member(id types.ID) *Member {
c.Lock()
defer c.Unlock()
return c.members[id].Clone()
}
func (c *RaftCluster) VotingMembers() []*Member {
c.Lock()
defer c.Unlock()
var ms MembersByID
for _, m := range c.members {
if !m.IsLearner {
ms = append(ms, m.Clone())
}
}
sort.Sort(ms)
return []*Member(ms)
}
// MemberByName returns a Member with the given name if exists.
// If more than one member has the given name, it will panic.
func (c *RaftCluster) MemberByName(name string) *Member {
c.Lock()
defer c.Unlock()
var memb *Member
for _, m := range c.members {
if m.Name == name {
if memb != nil {
if c.lg != nil {
c.lg.Panic("two member with same name found", zap.String("name", name))
} else {
plog.Panicf("two members with the given name %q exist", name)
}
}
memb = m
}
}
return memb.Clone()
}
func (c *RaftCluster) MemberIDs() []types.ID {
c.Lock()
defer c.Unlock()
var ids []types.ID
for _, m := range c.members {
ids = append(ids, m.ID)
}
sort.Sort(types.IDSlice(ids))
return ids
}
func (c *RaftCluster) IsIDRemoved(id types.ID) bool {
c.Lock()
defer c.Unlock()
return c.removed[id]
}
// PeerURLs returns a list of all peer addresses.
// The returned list is sorted in ascending lexicographical order.
func (c *RaftCluster) PeerURLs() []string {
c.Lock()
defer c.Unlock()
urls := make([]string, 0)
for _, p := range c.members {
urls = append(urls, p.PeerURLs...)
}
sort.Strings(urls)
return urls
}
// ClientURLs returns a list of all client addresses.
// The returned list is sorted in ascending lexicographical order.
func (c *RaftCluster) ClientURLs() []string {
c.Lock()
defer c.Unlock()
urls := make([]string, 0)
for _, p := range c.members {
urls = append(urls, p.ClientURLs...)
}
sort.Strings(urls)
return urls
}
func (c *RaftCluster) String() string {
c.Lock()
defer c.Unlock()
b := &bytes.Buffer{}
fmt.Fprintf(b, "{ClusterID:%s ", c.cid)
var ms []string
for _, m := range c.members {
ms = append(ms, fmt.Sprintf("%+v", m))
}
fmt.Fprintf(b, "Members:[%s] ", strings.Join(ms, " "))
var ids []string
for id := range c.removed {
ids = append(ids, id.String())
}
fmt.Fprintf(b, "RemovedMemberIDs:[%s]}", strings.Join(ids, " "))
return b.String()
}
func (c *RaftCluster) genID() {
mIDs := c.MemberIDs()
b := make([]byte, 8*len(mIDs))
for i, id := range mIDs {
binary.BigEndian.PutUint64(b[8*i:], uint64(id))
}
hash := sha1.Sum(b)
c.cid = types.ID(binary.BigEndian.Uint64(hash[:8]))
}
func (c *RaftCluster) SetID(localID, cid types.ID) {
c.localID = localID
c.cid = cid
}
func (c *RaftCluster) SetStore(st v2store.Store) { c.v2store = st }
func (c *RaftCluster) SetBackend(be backend.Backend) {
c.be = be
mustCreateBackendBuckets(c.be)
}
func (c *RaftCluster) Recover(onSet func(*zap.Logger, *semver.Version)) {
c.Lock()
defer c.Unlock()
c.members, c.removed = membersFromStore(c.lg, c.v2store)
c.version = clusterVersionFromStore(c.lg, c.v2store)
mustDetectDowngrade(c.lg, c.version)
onSet(c.lg, c.version)
for _, m := range c.members {
if c.lg != nil {
c.lg.Info(
"recovered/added member from store",
zap.String("cluster-id", c.cid.String()),
zap.String("local-member-id", c.localID.String()),
zap.String("recovered-remote-peer-id", m.ID.String()),
zap.Strings("recovered-remote-peer-urls", m.PeerURLs),
)
} else {
plog.Infof("added member %s %v to cluster %s from store", m.ID, m.PeerURLs, c.cid)
}
}
if c.version != nil {
if c.lg != nil {
c.lg.Info(
"set cluster version from store",
zap.String("cluster-version", version.Cluster(c.version.String())),
)
} else {
plog.Infof("set the cluster version to %v from store", version.Cluster(c.version.String()))
}
}
}
// ValidateConfigurationChange takes a proposed ConfChange and
// ensures that it is still valid.
func (c *RaftCluster) ValidateConfigurationChange(cc raftpb.ConfChange) error {
members, removed := membersFromStore(c.lg, c.v2store)
id := types.ID(cc.NodeID)
if removed[id] {
return ErrIDRemoved
}
switch cc.Type {
case raftpb.ConfChangeAddNode, raftpb.ConfChangeAddLearnerNode:
confChangeContext := new(ConfigChangeContext)
if err := json.Unmarshal(cc.Context, confChangeContext); err != nil {
if c.lg != nil {
c.lg.Panic("failed to unmarshal confChangeContext", zap.Error(err))
} else {
plog.Panicf("unmarshal confChangeContext should never fail: %v", err)
}
}
if confChangeContext.IsPromote { // promoting a learner member to voting member
if members[id] == nil {
return ErrIDNotFound
}
if !members[id].IsLearner {
return ErrMemberNotLearner
}
} else { // adding a new member
if members[id] != nil {
return ErrIDExists
}
urls := make(map[string]bool)
for _, m := range members {
for _, u := range m.PeerURLs {
urls[u] = true
}
}
for _, u := range confChangeContext.Member.PeerURLs {
if urls[u] {
return ErrPeerURLexists
}
}
if confChangeContext.Member.IsLearner { // the new member is a learner
numLearners := 0
for _, m := range members {
if m.IsLearner {
numLearners++
}
}
if numLearners+1 > maxLearners {
return ErrTooManyLearners
}
}
}
case raftpb.ConfChangeRemoveNode:
if members[id] == nil {
return ErrIDNotFound
}
case raftpb.ConfChangeUpdateNode:
if members[id] == nil {
return ErrIDNotFound
}
urls := make(map[string]bool)
for _, m := range members {
if m.ID == id {
continue
}
for _, u := range m.PeerURLs {
urls[u] = true
}
}
m := new(Member)
if err := json.Unmarshal(cc.Context, m); err != nil {
if c.lg != nil {
c.lg.Panic("failed to unmarshal member", zap.Error(err))
} else {
plog.Panicf("unmarshal member should never fail: %v", err)
}
}
for _, u := range m.PeerURLs {
if urls[u] {
return ErrPeerURLexists
}
}
default:
if c.lg != nil {
c.lg.Panic("unknown ConfChange type", zap.String("type", cc.Type.String()))
} else {
plog.Panicf("ConfChange type should be either AddNode, RemoveNode or UpdateNode")
}
}
return nil
}
// AddMember adds a new Member into the cluster, and saves the given member's
// raftAttributes into the store. The given member should have empty attributes.
// A Member with a matching id must not exist.
func (c *RaftCluster) AddMember(m *Member) {
c.Lock()
defer c.Unlock()
if c.v2store != nil {
mustSaveMemberToStore(c.v2store, m)
}
if c.be != nil {
mustSaveMemberToBackend(c.be, m)
}
c.members[m.ID] = m
if c.lg != nil {
c.lg.Info(
"added member",
zap.String("cluster-id", c.cid.String()),
zap.String("local-member-id", c.localID.String()),
zap.String("added-peer-id", m.ID.String()),
zap.Strings("added-peer-peer-urls", m.PeerURLs),
)
} else {
plog.Infof("added member %s %v to cluster %s", m.ID, m.PeerURLs, c.cid)
}
}
// RemoveMember removes a member from the store.
// The given id MUST exist, or the function panics.
func (c *RaftCluster) RemoveMember(id types.ID) {
c.Lock()
defer c.Unlock()
if c.v2store != nil {
mustDeleteMemberFromStore(c.v2store, id)
}
if c.be != nil {
mustDeleteMemberFromBackend(c.be, id)
}
m, ok := c.members[id]
delete(c.members, id)
c.removed[id] = true
if c.lg != nil {
if ok {
c.lg.Info(
"removed member",
zap.String("cluster-id", c.cid.String()),
zap.String("local-member-id", c.localID.String()),
zap.String("removed-remote-peer-id", id.String()),
zap.Strings("removed-remote-peer-urls", m.PeerURLs),
)
} else {
c.lg.Warn(
"skipped removing already removed member",
zap.String("cluster-id", c.cid.String()),
zap.String("local-member-id", c.localID.String()),
zap.String("removed-remote-peer-id", id.String()),
)
}
} else {
plog.Infof("removed member %s from cluster %s", id, c.cid)
}
}
func (c *RaftCluster) UpdateAttributes(id types.ID, attr Attributes) {
c.Lock()
defer c.Unlock()
if m, ok := c.members[id]; ok {
m.Attributes = attr
if c.v2store != nil {
mustUpdateMemberAttrInStore(c.v2store, m)
}
if c.be != nil {
mustSaveMemberToBackend(c.be, m)
}
return
}
_, ok := c.removed[id]
if !ok {
if c.lg != nil {
c.lg.Panic(
"failed to update; member unknown",
zap.String("cluster-id", c.cid.String()),
zap.String("local-member-id", c.localID.String()),
zap.String("unknown-remote-peer-id", id.String()),
)
} else {
plog.Panicf("error updating attributes of unknown member %s", id)
}
}
if c.lg != nil {
c.lg.Warn(
"skipped attributes update of removed member",
zap.String("cluster-id", c.cid.String()),
zap.String("local-member-id", c.localID.String()),
zap.String("updated-peer-id", id.String()),
)
} else {
plog.Warningf("skipped updating attributes of removed member %s", id)
}
}
// PromoteMember marks the member's IsLearner RaftAttributes to false.
func (c *RaftCluster) PromoteMember(id types.ID) {
c.Lock()
defer c.Unlock()
c.members[id].RaftAttributes.IsLearner = false
if c.v2store != nil {
mustUpdateMemberInStore(c.v2store, c.members[id])
}
if c.be != nil {
mustSaveMemberToBackend(c.be, c.members[id])
}
if c.lg != nil {
c.lg.Info(
"promote member",
zap.String("cluster-id", c.cid.String()),
zap.String("local-member-id", c.localID.String()),
)
} else {
plog.Noticef("promote member %s in cluster %s", id, c.cid)
}
}
func (c *RaftCluster) UpdateRaftAttributes(id types.ID, raftAttr RaftAttributes) {
c.Lock()
defer c.Unlock()
c.members[id].RaftAttributes = raftAttr
if c.v2store != nil {
mustUpdateMemberInStore(c.v2store, c.members[id])
}
if c.be != nil {
mustSaveMemberToBackend(c.be, c.members[id])
}
if c.lg != nil {
c.lg.Info(
"updated member",
zap.String("cluster-id", c.cid.String()),
zap.String("local-member-id", c.localID.String()),
zap.String("updated-remote-peer-id", id.String()),
zap.Strings("updated-remote-peer-urls", raftAttr.PeerURLs),
)
} else {
plog.Noticef("updated member %s %v in cluster %s", id, raftAttr.PeerURLs, c.cid)
}
}
func (c *RaftCluster) Version() *semver.Version {
c.Lock()
defer c.Unlock()
if c.version == nil {
return nil
}
return semver.Must(semver.NewVersion(c.version.String()))
}
func (c *RaftCluster) SetVersion(ver *semver.Version, onSet func(*zap.Logger, *semver.Version)) {
c.Lock()
defer c.Unlock()
if c.version != nil {
if c.lg != nil {
c.lg.Info(
"updated cluster version",
zap.String("cluster-id", c.cid.String()),
zap.String("local-member-id", c.localID.String()),
zap.String("from", version.Cluster(c.version.String())),
zap.String("from", version.Cluster(ver.String())),
)
} else {
plog.Noticef("updated the cluster version from %v to %v", version.Cluster(c.version.String()), version.Cluster(ver.String()))
}
} else {
if c.lg != nil {
c.lg.Info(
"set initial cluster version",
zap.String("cluster-id", c.cid.String()),
zap.String("local-member-id", c.localID.String()),
zap.String("cluster-version", version.Cluster(ver.String())),
)
} else {
plog.Noticef("set the initial cluster version to %v", version.Cluster(ver.String()))
}
}
oldVer := c.version
c.version = ver
mustDetectDowngrade(c.lg, c.version)
if c.v2store != nil {
mustSaveClusterVersionToStore(c.v2store, ver)
}
if c.be != nil {
mustSaveClusterVersionToBackend(c.be, ver)
}
if oldVer != nil {
ClusterVersionMetrics.With(prometheus.Labels{"cluster_version": version.Cluster(oldVer.String())}).Set(0)
}
ClusterVersionMetrics.With(prometheus.Labels{"cluster_version": version.Cluster(ver.String())}).Set(1)
onSet(c.lg, ver)
}
func (c *RaftCluster) IsReadyToAddVotingMember() bool {
nmembers := 1
nstarted := 0
for _, member := range c.VotingMembers() {
if member.IsStarted() {
nstarted++
}
nmembers++
}
if nstarted == 1 && nmembers == 2 {
// a case of adding a new node to 1-member cluster for restoring cluster data
// https://github.com/etcd-io/etcd/blob/master/Documentation/v2/admin_guide.md#restoring-the-cluster
if c.lg != nil {
c.lg.Debug("number of started member is 1; can accept add member request")
} else {
plog.Debugf("The number of started member is 1. This cluster can accept add member request.")
}
return true
}
nquorum := nmembers/2 + 1
if nstarted < nquorum {
if c.lg != nil {
c.lg.Warn(
"rejecting member add; started member will be less than quorum",
zap.Int("number-of-started-member", nstarted),
zap.Int("quorum", nquorum),
zap.String("cluster-id", c.cid.String()),
zap.String("local-member-id", c.localID.String()),
)
} else {
plog.Warningf("Reject add member request: the number of started member (%d) will be less than the quorum number of the cluster (%d)", nstarted, nquorum)
}
return false
}
return true
}
func (c *RaftCluster) IsReadyToRemoveVotingMember(id uint64) bool {
nmembers := 0
nstarted := 0
for _, member := range c.VotingMembers() {
if uint64(member.ID) == id {
continue
}
if member.IsStarted() {
nstarted++
}
nmembers++
}
nquorum := nmembers/2 + 1
if nstarted < nquorum {
if c.lg != nil {
c.lg.Warn(
"rejecting member remove; started member will be less than quorum",
zap.Int("number-of-started-member", nstarted),
zap.Int("quorum", nquorum),
zap.String("cluster-id", c.cid.String()),
zap.String("local-member-id", c.localID.String()),
)
} else {
plog.Warningf("Reject remove member request: the number of started member (%d) will be less than the quorum number of the cluster (%d)", nstarted, nquorum)
}
return false
}
return true
}
func (c *RaftCluster) IsReadyToPromoteMember(id uint64) bool {
nmembers := 1 // We count the learner to be promoted for the future quorum
nstarted := 1 // and we also count it as started.
for _, member := range c.VotingMembers() {
if member.IsStarted() {
nstarted++
}
nmembers++
}
nquorum := nmembers/2 + 1
if nstarted < nquorum {
if c.lg != nil {
c.lg.Warn(
"rejecting member promote; started member will be less than quorum",
zap.Int("number-of-started-member", nstarted),
zap.Int("quorum", nquorum),
zap.String("cluster-id", c.cid.String()),
zap.String("local-member-id", c.localID.String()),
)
} else {
plog.Warningf("Reject promote member request: the number of started member (%d) will be less than the quorum number of the cluster (%d)", nstarted, nquorum)
}
return false
}
return true
}
func membersFromStore(lg *zap.Logger, st v2store.Store) (map[types.ID]*Member, map[types.ID]bool) {
members := make(map[types.ID]*Member)
removed := make(map[types.ID]bool)
e, err := st.Get(StoreMembersPrefix, true, true)
if err != nil {
if isKeyNotFound(err) {
return members, removed
}
if lg != nil {
lg.Panic("failed to get members from store", zap.String("path", StoreMembersPrefix), zap.Error(err))
} else {
plog.Panicf("get storeMembers should never fail: %v", err)
}
}
for _, n := range e.Node.Nodes {
var m *Member
m, err = nodeToMember(n)
if err != nil {
if lg != nil {
lg.Panic("failed to nodeToMember", zap.Error(err))
} else {
plog.Panicf("nodeToMember should never fail: %v", err)
}
}
members[m.ID] = m
}
e, err = st.Get(storeRemovedMembersPrefix, true, true)
if err != nil {
if isKeyNotFound(err) {
return members, removed
}
if lg != nil {
lg.Panic(
"failed to get removed members from store",
zap.String("path", storeRemovedMembersPrefix),
zap.Error(err),
)
} else {
plog.Panicf("get storeRemovedMembers should never fail: %v", err)
}
}
for _, n := range e.Node.Nodes {
removed[MustParseMemberIDFromKey(n.Key)] = true
}
return members, removed
}
func clusterVersionFromStore(lg *zap.Logger, st v2store.Store) *semver.Version {
e, err := st.Get(path.Join(storePrefix, "version"), false, false)
if err != nil {
if isKeyNotFound(err) {
return nil
}
if lg != nil {
lg.Panic(
"failed to get cluster version from store",
zap.String("path", path.Join(storePrefix, "version")),
zap.Error(err),
)
} else {
plog.Panicf("unexpected error (%v) when getting cluster version from store", err)
}
}
return semver.Must(semver.NewVersion(*e.Node.Value))
}
// ValidateClusterAndAssignIDs validates the local cluster by matching the PeerURLs
// with the existing cluster. If the validation succeeds, it assigns the IDs
// from the existing cluster to the local cluster.
// If the validation fails, an error will be returned.
func ValidateClusterAndAssignIDs(lg *zap.Logger, local *RaftCluster, existing *RaftCluster) error {
ems := existing.Members()
lms := local.Members()
if len(ems) != len(lms) {
return fmt.Errorf("member count is unequal")
}
sort.Sort(MembersByPeerURLs(ems))
sort.Sort(MembersByPeerURLs(lms))
ctx, cancel := context.WithTimeout(context.TODO(), 30*time.Second)
defer cancel()
for i := range ems {
if ok, err := netutil.URLStringsEqual(ctx, lg, ems[i].PeerURLs, lms[i].PeerURLs); !ok {
return fmt.Errorf("unmatched member while checking PeerURLs (%v)", err)
}
lms[i].ID = ems[i].ID
}
local.members = make(map[types.ID]*Member)
for _, m := range lms {
local.members[m.ID] = m
}
return nil
}
func mustDetectDowngrade(lg *zap.Logger, cv *semver.Version) {
lv := semver.Must(semver.NewVersion(version.Version))
// only keep major.minor version for comparison against cluster version
lv = &semver.Version{Major: lv.Major, Minor: lv.Minor}
if cv != nil && lv.LessThan(*cv) {
if lg != nil {
lg.Fatal(
"invalid downgrade; server version is lower than determined cluster version",
zap.String("current-server-version", version.Version),
zap.String("determined-cluster-version", version.Cluster(cv.String())),
)
} else {
plog.Fatalf("cluster cannot be downgraded (current version: %s is lower than determined cluster version: %s).", version.Version, version.Cluster(cv.String()))
}
}
}
// IsLocalMemberLearner returns if the local member is raft learner
func (c *RaftCluster) IsLocalMemberLearner() bool {
c.Lock()
defer c.Unlock()
localMember, ok := c.members[c.localID]
if !ok {
if c.lg != nil {
c.lg.Error(
"failed to find local ID in cluster members",
zap.String("cluster-id", c.cid.String()),
zap.String("local-member-id", c.localID.String()),
)
} else {
plog.Errorf("failed to find local ID %s in cluster %s", c.localID.String(), c.cid.String())
}
return false
}
return localMember.IsLearner
}
// IsMemberExist returns if the member with the given id exists in cluster.
func (c *RaftCluster) IsMemberExist(id types.ID) bool {
c.Lock()
defer c.Unlock()
_, ok := c.members[id]
return ok
}
// VotingMemberIDs returns the ID of voting members in cluster.
func (c *RaftCluster) VotingMemberIDs() []types.ID {
c.Lock()
defer c.Unlock()
var ids []types.ID
for _, m := range c.members {
if !m.IsLearner {
ids = append(ids, m.ID)
}
}
sort.Sort(types.IDSlice(ids))
return ids
}