khenaidoo | d948f77 | 2021-08-11 17:49:24 -0400 | [diff] [blame] | 1 | // Copyright 2015 The etcd Authors |
| 2 | // |
| 3 | // Licensed under the Apache License, Version 2.0 (the "License"); |
| 4 | // you may not use this file except in compliance with the License. |
| 5 | // You may obtain a copy of the License at |
| 6 | // |
| 7 | // http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | // |
| 9 | // Unless required by applicable law or agreed to in writing, software |
| 10 | // distributed under the License is distributed on an "AS IS" BASIS, |
| 11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 12 | // See the License for the specific language governing permissions and |
| 13 | // limitations under the License. |
| 14 | |
| 15 | package etcdserver |
| 16 | |
| 17 | import ( |
| 18 | "context" |
| 19 | "encoding/json" |
| 20 | "expvar" |
| 21 | "fmt" |
| 22 | "math" |
| 23 | "math/rand" |
| 24 | "net/http" |
| 25 | "os" |
| 26 | "path" |
| 27 | "regexp" |
| 28 | "sync" |
| 29 | "sync/atomic" |
| 30 | "time" |
| 31 | |
| 32 | "github.com/coreos/etcd/alarm" |
| 33 | "github.com/coreos/etcd/auth" |
| 34 | "github.com/coreos/etcd/compactor" |
| 35 | "github.com/coreos/etcd/discovery" |
| 36 | "github.com/coreos/etcd/etcdserver/api" |
| 37 | "github.com/coreos/etcd/etcdserver/api/v2http/httptypes" |
| 38 | pb "github.com/coreos/etcd/etcdserver/etcdserverpb" |
| 39 | "github.com/coreos/etcd/etcdserver/membership" |
| 40 | "github.com/coreos/etcd/etcdserver/stats" |
| 41 | "github.com/coreos/etcd/lease" |
| 42 | "github.com/coreos/etcd/lease/leasehttp" |
| 43 | "github.com/coreos/etcd/mvcc" |
| 44 | "github.com/coreos/etcd/mvcc/backend" |
| 45 | "github.com/coreos/etcd/pkg/fileutil" |
| 46 | "github.com/coreos/etcd/pkg/idutil" |
| 47 | "github.com/coreos/etcd/pkg/pbutil" |
| 48 | "github.com/coreos/etcd/pkg/runtime" |
| 49 | "github.com/coreos/etcd/pkg/schedule" |
| 50 | "github.com/coreos/etcd/pkg/types" |
| 51 | "github.com/coreos/etcd/pkg/wait" |
| 52 | "github.com/coreos/etcd/raft" |
| 53 | "github.com/coreos/etcd/raft/raftpb" |
| 54 | "github.com/coreos/etcd/rafthttp" |
| 55 | "github.com/coreos/etcd/snap" |
| 56 | "github.com/coreos/etcd/store" |
| 57 | "github.com/coreos/etcd/version" |
| 58 | "github.com/coreos/etcd/wal" |
| 59 | |
| 60 | "github.com/coreos/go-semver/semver" |
| 61 | "github.com/coreos/pkg/capnslog" |
| 62 | "github.com/prometheus/client_golang/prometheus" |
| 63 | ) |
| 64 | |
| 65 | const ( |
| 66 | DefaultSnapCount = 100000 |
| 67 | |
| 68 | StoreClusterPrefix = "/0" |
| 69 | StoreKeysPrefix = "/1" |
| 70 | |
| 71 | // HealthInterval is the minimum time the cluster should be healthy |
| 72 | // before accepting add member requests. |
| 73 | HealthInterval = 5 * time.Second |
| 74 | |
| 75 | purgeFileInterval = 30 * time.Second |
| 76 | // monitorVersionInterval should be smaller than the timeout |
| 77 | // on the connection. Or we will not be able to reuse the connection |
| 78 | // (since it will timeout). |
| 79 | monitorVersionInterval = rafthttp.ConnWriteTimeout - time.Second |
| 80 | |
| 81 | // max number of in-flight snapshot messages etcdserver allows to have |
| 82 | // This number is more than enough for most clusters with 5 machines. |
| 83 | maxInFlightMsgSnap = 16 |
| 84 | |
| 85 | releaseDelayAfterSnapshot = 30 * time.Second |
| 86 | |
| 87 | // maxPendingRevokes is the maximum number of outstanding expired lease revocations. |
| 88 | maxPendingRevokes = 16 |
| 89 | |
| 90 | recommendedMaxRequestBytes = 10 * 1024 * 1024 |
| 91 | ) |
| 92 | |
| 93 | var ( |
| 94 | plog = capnslog.NewPackageLogger("github.com/coreos/etcd", "etcdserver") |
| 95 | |
| 96 | storeMemberAttributeRegexp = regexp.MustCompile(path.Join(membership.StoreMembersPrefix, "[[:xdigit:]]{1,16}", "attributes")) |
| 97 | ) |
| 98 | |
| 99 | func init() { |
| 100 | rand.Seed(time.Now().UnixNano()) |
| 101 | |
| 102 | expvar.Publish( |
| 103 | "file_descriptor_limit", |
| 104 | expvar.Func( |
| 105 | func() interface{} { |
| 106 | n, _ := runtime.FDLimit() |
| 107 | return n |
| 108 | }, |
| 109 | ), |
| 110 | ) |
| 111 | } |
| 112 | |
| 113 | type Response struct { |
| 114 | Term uint64 |
| 115 | Index uint64 |
| 116 | Event *store.Event |
| 117 | Watcher store.Watcher |
| 118 | Err error |
| 119 | } |
| 120 | |
| 121 | type ServerV2 interface { |
| 122 | Server |
| 123 | // Do takes a V2 request and attempts to fulfill it, returning a Response. |
| 124 | Do(ctx context.Context, r pb.Request) (Response, error) |
| 125 | stats.Stats |
| 126 | ClientCertAuthEnabled() bool |
| 127 | } |
| 128 | |
| 129 | type ServerV3 interface { |
| 130 | Server |
| 131 | ID() types.ID |
| 132 | RaftTimer |
| 133 | } |
| 134 | |
| 135 | func (s *EtcdServer) ClientCertAuthEnabled() bool { return s.Cfg.ClientCertAuthEnabled } |
| 136 | |
| 137 | type Server interface { |
| 138 | // Leader returns the ID of the leader Server. |
| 139 | Leader() types.ID |
| 140 | |
| 141 | // AddMember attempts to add a member into the cluster. It will return |
| 142 | // ErrIDRemoved if member ID is removed from the cluster, or return |
| 143 | // ErrIDExists if member ID exists in the cluster. |
| 144 | AddMember(ctx context.Context, memb membership.Member) ([]*membership.Member, error) |
| 145 | // RemoveMember attempts to remove a member from the cluster. It will |
| 146 | // return ErrIDRemoved if member ID is removed from the cluster, or return |
| 147 | // ErrIDNotFound if member ID is not in the cluster. |
| 148 | RemoveMember(ctx context.Context, id uint64) ([]*membership.Member, error) |
| 149 | // UpdateMember attempts to update an existing member in the cluster. It will |
| 150 | // return ErrIDNotFound if the member ID does not exist. |
| 151 | UpdateMember(ctx context.Context, updateMemb membership.Member) ([]*membership.Member, error) |
| 152 | |
| 153 | // ClusterVersion is the cluster-wide minimum major.minor version. |
| 154 | // Cluster version is set to the min version that an etcd member is |
| 155 | // compatible with when first bootstrap. |
| 156 | // |
| 157 | // ClusterVersion is nil until the cluster is bootstrapped (has a quorum). |
| 158 | // |
| 159 | // During a rolling upgrades, the ClusterVersion will be updated |
| 160 | // automatically after a sync. (5 second by default) |
| 161 | // |
| 162 | // The API/raft component can utilize ClusterVersion to determine if |
| 163 | // it can accept a client request or a raft RPC. |
| 164 | // NOTE: ClusterVersion might be nil when etcd 2.1 works with etcd 2.0 and |
| 165 | // the leader is etcd 2.0. etcd 2.0 leader will not update clusterVersion since |
| 166 | // this feature is introduced post 2.0. |
| 167 | ClusterVersion() *semver.Version |
| 168 | Cluster() api.Cluster |
| 169 | Alarms() []*pb.AlarmMember |
| 170 | } |
| 171 | |
| 172 | // EtcdServer is the production implementation of the Server interface |
| 173 | type EtcdServer struct { |
| 174 | // inflightSnapshots holds count the number of snapshots currently inflight. |
| 175 | inflightSnapshots int64 // must use atomic operations to access; keep 64-bit aligned. |
| 176 | appliedIndex uint64 // must use atomic operations to access; keep 64-bit aligned. |
| 177 | committedIndex uint64 // must use atomic operations to access; keep 64-bit aligned. |
| 178 | // consistIndex used to hold the offset of current executing entry |
| 179 | // It is initialized to 0 before executing any entry. |
| 180 | consistIndex consistentIndex // must use atomic operations to access; keep 64-bit aligned. |
| 181 | r raftNode // uses 64-bit atomics; keep 64-bit aligned. |
| 182 | |
| 183 | readych chan struct{} |
| 184 | Cfg ServerConfig |
| 185 | |
| 186 | w wait.Wait |
| 187 | |
| 188 | readMu sync.RWMutex |
| 189 | // read routine notifies etcd server that it waits for reading by sending an empty struct to |
| 190 | // readwaitC |
| 191 | readwaitc chan struct{} |
| 192 | // readNotifier is used to notify the read routine that it can process the request |
| 193 | // when there is no error |
| 194 | readNotifier *notifier |
| 195 | |
| 196 | // stop signals the run goroutine should shutdown. |
| 197 | stop chan struct{} |
| 198 | // stopping is closed by run goroutine on shutdown. |
| 199 | stopping chan struct{} |
| 200 | // done is closed when all goroutines from start() complete. |
| 201 | done chan struct{} |
| 202 | leaderChanged chan struct{} |
| 203 | leaderChangedMu sync.RWMutex |
| 204 | |
| 205 | errorc chan error |
| 206 | id types.ID |
| 207 | attributes membership.Attributes |
| 208 | |
| 209 | cluster *membership.RaftCluster |
| 210 | |
| 211 | store store.Store |
| 212 | snapshotter *snap.Snapshotter |
| 213 | |
| 214 | applyV2 ApplierV2 |
| 215 | |
| 216 | // applyV3 is the applier with auth and quotas |
| 217 | applyV3 applierV3 |
| 218 | // applyV3Base is the core applier without auth or quotas |
| 219 | applyV3Base applierV3 |
| 220 | applyWait wait.WaitTime |
| 221 | |
| 222 | kv mvcc.ConsistentWatchableKV |
| 223 | lessor lease.Lessor |
| 224 | bemu sync.Mutex |
| 225 | be backend.Backend |
| 226 | authStore auth.AuthStore |
| 227 | alarmStore *alarm.AlarmStore |
| 228 | |
| 229 | stats *stats.ServerStats |
| 230 | lstats *stats.LeaderStats |
| 231 | |
| 232 | SyncTicker *time.Ticker |
| 233 | // compactor is used to auto-compact the KV. |
| 234 | compactor compactor.Compactor |
| 235 | |
| 236 | // peerRt used to send requests (version, lease) to peers. |
| 237 | peerRt http.RoundTripper |
| 238 | reqIDGen *idutil.Generator |
| 239 | |
| 240 | // forceVersionC is used to force the version monitor loop |
| 241 | // to detect the cluster version immediately. |
| 242 | forceVersionC chan struct{} |
| 243 | |
| 244 | // wgMu blocks concurrent waitgroup mutation while server stopping |
| 245 | wgMu sync.RWMutex |
| 246 | // wg is used to wait for the go routines that depends on the server state |
| 247 | // to exit when stopping the server. |
| 248 | wg sync.WaitGroup |
| 249 | |
| 250 | // ctx is used for etcd-initiated requests that may need to be canceled |
| 251 | // on etcd server shutdown. |
| 252 | ctx context.Context |
| 253 | cancel context.CancelFunc |
| 254 | |
| 255 | leadTimeMu sync.RWMutex |
| 256 | leadElectedTime time.Time |
| 257 | } |
| 258 | |
| 259 | // NewServer creates a new EtcdServer from the supplied configuration. The |
| 260 | // configuration is considered static for the lifetime of the EtcdServer. |
| 261 | func NewServer(cfg ServerConfig) (srv *EtcdServer, err error) { |
| 262 | st := store.New(StoreClusterPrefix, StoreKeysPrefix) |
| 263 | |
| 264 | var ( |
| 265 | w *wal.WAL |
| 266 | n raft.Node |
| 267 | s *raft.MemoryStorage |
| 268 | id types.ID |
| 269 | cl *membership.RaftCluster |
| 270 | ) |
| 271 | |
| 272 | if cfg.MaxRequestBytes > recommendedMaxRequestBytes { |
| 273 | plog.Warningf("MaxRequestBytes %v exceeds maximum recommended size %v", cfg.MaxRequestBytes, recommendedMaxRequestBytes) |
| 274 | } |
| 275 | |
| 276 | if terr := fileutil.TouchDirAll(cfg.DataDir); terr != nil { |
| 277 | return nil, fmt.Errorf("cannot access data directory: %v", terr) |
| 278 | } |
| 279 | |
| 280 | haveWAL := wal.Exist(cfg.WALDir()) |
| 281 | |
| 282 | if err = fileutil.TouchDirAll(cfg.SnapDir()); err != nil { |
| 283 | plog.Fatalf("create snapshot directory error: %v", err) |
| 284 | } |
| 285 | ss := snap.New(cfg.SnapDir()) |
| 286 | |
| 287 | bepath := cfg.backendPath() |
| 288 | beExist := fileutil.Exist(bepath) |
| 289 | be := openBackend(cfg) |
| 290 | |
| 291 | defer func() { |
| 292 | if err != nil { |
| 293 | be.Close() |
| 294 | } |
| 295 | }() |
| 296 | |
| 297 | prt, err := rafthttp.NewRoundTripper(cfg.PeerTLSInfo, cfg.peerDialTimeout()) |
| 298 | if err != nil { |
| 299 | return nil, err |
| 300 | } |
| 301 | var ( |
| 302 | remotes []*membership.Member |
| 303 | snapshot *raftpb.Snapshot |
| 304 | ) |
| 305 | |
| 306 | switch { |
| 307 | case !haveWAL && !cfg.NewCluster: |
| 308 | if err = cfg.VerifyJoinExisting(); err != nil { |
| 309 | return nil, err |
| 310 | } |
| 311 | cl, err = membership.NewClusterFromURLsMap(cfg.InitialClusterToken, cfg.InitialPeerURLsMap) |
| 312 | if err != nil { |
| 313 | return nil, err |
| 314 | } |
| 315 | existingCluster, gerr := GetClusterFromRemotePeers(getRemotePeerURLs(cl, cfg.Name), prt) |
| 316 | if gerr != nil { |
| 317 | return nil, fmt.Errorf("cannot fetch cluster info from peer urls: %v", gerr) |
| 318 | } |
| 319 | if err = membership.ValidateClusterAndAssignIDs(cl, existingCluster); err != nil { |
| 320 | return nil, fmt.Errorf("error validating peerURLs %s: %v", existingCluster, err) |
| 321 | } |
| 322 | if !isCompatibleWithCluster(cl, cl.MemberByName(cfg.Name).ID, prt) { |
| 323 | return nil, fmt.Errorf("incompatible with current running cluster") |
| 324 | } |
| 325 | |
| 326 | remotes = existingCluster.Members() |
| 327 | cl.SetID(existingCluster.ID()) |
| 328 | cl.SetStore(st) |
| 329 | cl.SetBackend(be) |
| 330 | cfg.Print() |
| 331 | id, n, s, w = startNode(cfg, cl, nil) |
| 332 | case !haveWAL && cfg.NewCluster: |
| 333 | if err = cfg.VerifyBootstrap(); err != nil { |
| 334 | return nil, err |
| 335 | } |
| 336 | cl, err = membership.NewClusterFromURLsMap(cfg.InitialClusterToken, cfg.InitialPeerURLsMap) |
| 337 | if err != nil { |
| 338 | return nil, err |
| 339 | } |
| 340 | m := cl.MemberByName(cfg.Name) |
| 341 | if isMemberBootstrapped(cl, cfg.Name, prt, cfg.bootstrapTimeout()) { |
| 342 | return nil, fmt.Errorf("member %s has already been bootstrapped", m.ID) |
| 343 | } |
| 344 | if cfg.ShouldDiscover() { |
| 345 | var str string |
| 346 | str, err = discovery.JoinCluster(cfg.DiscoveryURL, cfg.DiscoveryProxy, m.ID, cfg.InitialPeerURLsMap.String()) |
| 347 | if err != nil { |
| 348 | return nil, &DiscoveryError{Op: "join", Err: err} |
| 349 | } |
| 350 | var urlsmap types.URLsMap |
| 351 | urlsmap, err = types.NewURLsMap(str) |
| 352 | if err != nil { |
| 353 | return nil, err |
| 354 | } |
| 355 | if checkDuplicateURL(urlsmap) { |
| 356 | return nil, fmt.Errorf("discovery cluster %s has duplicate url", urlsmap) |
| 357 | } |
| 358 | if cl, err = membership.NewClusterFromURLsMap(cfg.InitialClusterToken, urlsmap); err != nil { |
| 359 | return nil, err |
| 360 | } |
| 361 | } |
| 362 | cl.SetStore(st) |
| 363 | cl.SetBackend(be) |
| 364 | cfg.PrintWithInitial() |
| 365 | id, n, s, w = startNode(cfg, cl, cl.MemberIDs()) |
| 366 | case haveWAL: |
| 367 | if err = fileutil.IsDirWriteable(cfg.MemberDir()); err != nil { |
| 368 | return nil, fmt.Errorf("cannot write to member directory: %v", err) |
| 369 | } |
| 370 | |
| 371 | if err = fileutil.IsDirWriteable(cfg.WALDir()); err != nil { |
| 372 | return nil, fmt.Errorf("cannot write to WAL directory: %v", err) |
| 373 | } |
| 374 | |
| 375 | if cfg.ShouldDiscover() { |
| 376 | plog.Warningf("discovery token ignored since a cluster has already been initialized. Valid log found at %q", cfg.WALDir()) |
| 377 | } |
| 378 | |
| 379 | // Find a snapshot to start/restart a raft node |
| 380 | walSnaps, serr := wal.ValidSnapshotEntries(cfg.WALDir()) |
| 381 | if serr != nil { |
| 382 | return nil, serr |
| 383 | } |
| 384 | // snapshot files can be orphaned if etcd crashes after writing them but before writing the corresponding |
| 385 | // wal log entries |
| 386 | snapshot, err = ss.LoadNewestAvailable(walSnaps) |
| 387 | if err != nil && err != snap.ErrNoSnapshot { |
| 388 | return nil, err |
| 389 | } |
| 390 | if snapshot != nil { |
| 391 | if err = st.Recovery(snapshot.Data); err != nil { |
| 392 | plog.Panicf("recovered store from snapshot error: %v", err) |
| 393 | } |
| 394 | plog.Infof("recovered store from snapshot at index %d", snapshot.Metadata.Index) |
| 395 | if be, err = recoverSnapshotBackend(cfg, be, *snapshot); err != nil { |
| 396 | plog.Panicf("recovering backend from snapshot error: %v", err) |
| 397 | } |
| 398 | } |
| 399 | cfg.Print() |
| 400 | if !cfg.ForceNewCluster { |
| 401 | id, cl, n, s, w = restartNode(cfg, snapshot) |
| 402 | } else { |
| 403 | id, cl, n, s, w = restartAsStandaloneNode(cfg, snapshot) |
| 404 | } |
| 405 | cl.SetStore(st) |
| 406 | cl.SetBackend(be) |
| 407 | cl.Recover(api.UpdateCapability) |
| 408 | if cl.Version() != nil && !cl.Version().LessThan(semver.Version{Major: 3}) && !beExist { |
| 409 | os.RemoveAll(bepath) |
| 410 | return nil, fmt.Errorf("database file (%v) of the backend is missing", bepath) |
| 411 | } |
| 412 | default: |
| 413 | return nil, fmt.Errorf("unsupported bootstrap config") |
| 414 | } |
| 415 | |
| 416 | if terr := fileutil.TouchDirAll(cfg.MemberDir()); terr != nil { |
| 417 | return nil, fmt.Errorf("cannot access member directory: %v", terr) |
| 418 | } |
| 419 | |
| 420 | sstats := stats.NewServerStats(cfg.Name, id.String()) |
| 421 | lstats := stats.NewLeaderStats(id.String()) |
| 422 | |
| 423 | heartbeat := time.Duration(cfg.TickMs) * time.Millisecond |
| 424 | srv = &EtcdServer{ |
| 425 | readych: make(chan struct{}), |
| 426 | Cfg: cfg, |
| 427 | errorc: make(chan error, 1), |
| 428 | store: st, |
| 429 | snapshotter: ss, |
| 430 | r: *newRaftNode( |
| 431 | raftNodeConfig{ |
| 432 | isIDRemoved: func(id uint64) bool { return cl.IsIDRemoved(types.ID(id)) }, |
| 433 | Node: n, |
| 434 | heartbeat: heartbeat, |
| 435 | raftStorage: s, |
| 436 | storage: NewStorage(w, ss), |
| 437 | }, |
| 438 | ), |
| 439 | id: id, |
| 440 | attributes: membership.Attributes{Name: cfg.Name, ClientURLs: cfg.ClientURLs.StringSlice()}, |
| 441 | cluster: cl, |
| 442 | stats: sstats, |
| 443 | lstats: lstats, |
| 444 | SyncTicker: time.NewTicker(500 * time.Millisecond), |
| 445 | peerRt: prt, |
| 446 | reqIDGen: idutil.NewGenerator(uint16(id), time.Now()), |
| 447 | forceVersionC: make(chan struct{}), |
| 448 | } |
| 449 | serverID.With(prometheus.Labels{"server_id": id.String()}).Set(1) |
| 450 | |
| 451 | srv.applyV2 = &applierV2store{store: srv.store, cluster: srv.cluster} |
| 452 | |
| 453 | srv.be = be |
| 454 | minTTL := time.Duration((3*cfg.ElectionTicks)/2) * heartbeat |
| 455 | |
| 456 | // always recover lessor before kv. When we recover the mvcc.KV it will reattach keys to its leases. |
| 457 | // If we recover mvcc.KV first, it will attach the keys to the wrong lessor before it recovers. |
| 458 | srv.lessor = lease.NewLessor(srv.be, int64(math.Ceil(minTTL.Seconds()))) |
| 459 | |
| 460 | tp, err := auth.NewTokenProvider(cfg.AuthToken, |
| 461 | func(index uint64) <-chan struct{} { |
| 462 | return srv.applyWait.Wait(index) |
| 463 | }, |
| 464 | time.Duration(cfg.TokenTTL)*time.Second, |
| 465 | ) |
| 466 | if err != nil { |
| 467 | plog.Warningf("failed to create token provider,err is %v", err) |
| 468 | return nil, err |
| 469 | } |
| 470 | srv.authStore = auth.NewAuthStore(srv.be, tp) |
| 471 | |
| 472 | srv.kv = mvcc.New(srv.be, srv.lessor, srv.authStore, &srv.consistIndex) |
| 473 | if beExist { |
| 474 | kvindex := srv.kv.ConsistentIndex() |
| 475 | // TODO: remove kvindex != 0 checking when we do not expect users to upgrade |
| 476 | // etcd from pre-3.0 release. |
| 477 | if snapshot != nil && kvindex < snapshot.Metadata.Index { |
| 478 | if kvindex != 0 { |
| 479 | return nil, fmt.Errorf("database file (%v index %d) does not match with snapshot (index %d).", bepath, kvindex, snapshot.Metadata.Index) |
| 480 | } |
| 481 | plog.Warningf("consistent index never saved (snapshot index=%d)", snapshot.Metadata.Index) |
| 482 | } |
| 483 | } |
| 484 | newSrv := srv // since srv == nil in defer if srv is returned as nil |
| 485 | defer func() { |
| 486 | // closing backend without first closing kv can cause |
| 487 | // resumed compactions to fail with closed tx errors |
| 488 | if err != nil { |
| 489 | newSrv.kv.Close() |
| 490 | } |
| 491 | }() |
| 492 | |
| 493 | srv.consistIndex.setConsistentIndex(srv.kv.ConsistentIndex()) |
| 494 | if num := cfg.AutoCompactionRetention; num != 0 { |
| 495 | srv.compactor, err = compactor.New(cfg.AutoCompactionMode, num, srv.kv, srv) |
| 496 | if err != nil { |
| 497 | return nil, err |
| 498 | } |
| 499 | srv.compactor.Run() |
| 500 | } |
| 501 | |
| 502 | srv.applyV3Base = srv.newApplierV3Backend() |
| 503 | if err = srv.restoreAlarms(); err != nil { |
| 504 | return nil, err |
| 505 | } |
| 506 | |
| 507 | // TODO: move transport initialization near the definition of remote |
| 508 | tr := &rafthttp.Transport{ |
| 509 | TLSInfo: cfg.PeerTLSInfo, |
| 510 | DialTimeout: cfg.peerDialTimeout(), |
| 511 | ID: id, |
| 512 | URLs: cfg.PeerURLs, |
| 513 | ClusterID: cl.ID(), |
| 514 | Raft: srv, |
| 515 | Snapshotter: ss, |
| 516 | ServerStats: sstats, |
| 517 | LeaderStats: lstats, |
| 518 | ErrorC: srv.errorc, |
| 519 | } |
| 520 | if err = tr.Start(); err != nil { |
| 521 | return nil, err |
| 522 | } |
| 523 | // add all remotes into transport |
| 524 | for _, m := range remotes { |
| 525 | if m.ID != id { |
| 526 | tr.AddRemote(m.ID, m.PeerURLs) |
| 527 | } |
| 528 | } |
| 529 | for _, m := range cl.Members() { |
| 530 | if m.ID != id { |
| 531 | tr.AddPeer(m.ID, m.PeerURLs) |
| 532 | } |
| 533 | } |
| 534 | srv.r.transport = tr |
| 535 | |
| 536 | return srv, nil |
| 537 | } |
| 538 | |
| 539 | func (s *EtcdServer) adjustTicks() { |
| 540 | clusterN := len(s.cluster.Members()) |
| 541 | |
| 542 | // single-node fresh start, or single-node recovers from snapshot |
| 543 | if clusterN == 1 { |
| 544 | ticks := s.Cfg.ElectionTicks - 1 |
| 545 | plog.Infof("%s as single-node; fast-forwarding %d ticks (election ticks %d)", s.ID(), ticks, s.Cfg.ElectionTicks) |
| 546 | s.r.advanceTicks(ticks) |
| 547 | return |
| 548 | } |
| 549 | |
| 550 | if !s.Cfg.InitialElectionTickAdvance { |
| 551 | plog.Infof("skipping initial election tick advance (election tick %d)", s.Cfg.ElectionTicks) |
| 552 | return |
| 553 | } |
| 554 | |
| 555 | // retry up to "rafthttp.ConnReadTimeout", which is 5-sec |
| 556 | // until peer connection reports; otherwise: |
| 557 | // 1. all connections failed, or |
| 558 | // 2. no active peers, or |
| 559 | // 3. restarted single-node with no snapshot |
| 560 | // then, do nothing, because advancing ticks would have no effect |
| 561 | waitTime := rafthttp.ConnReadTimeout |
| 562 | itv := 50 * time.Millisecond |
| 563 | for i := int64(0); i < int64(waitTime/itv); i++ { |
| 564 | select { |
| 565 | case <-time.After(itv): |
| 566 | case <-s.stopping: |
| 567 | return |
| 568 | } |
| 569 | |
| 570 | peerN := s.r.transport.ActivePeers() |
| 571 | if peerN > 1 { |
| 572 | // multi-node received peer connection reports |
| 573 | // adjust ticks, in case slow leader message receive |
| 574 | ticks := s.Cfg.ElectionTicks - 2 |
| 575 | plog.Infof("%s initialzed peer connection; fast-forwarding %d ticks (election ticks %d) with %d active peer(s)", s.ID(), ticks, s.Cfg.ElectionTicks, peerN) |
| 576 | s.r.advanceTicks(ticks) |
| 577 | return |
| 578 | } |
| 579 | } |
| 580 | } |
| 581 | |
| 582 | // Start performs any initialization of the Server necessary for it to |
| 583 | // begin serving requests. It must be called before Do or Process. |
| 584 | // Start must be non-blocking; any long-running server functionality |
| 585 | // should be implemented in goroutines. |
| 586 | func (s *EtcdServer) Start() { |
| 587 | s.start() |
| 588 | s.goAttach(func() { s.adjustTicks() }) |
| 589 | s.goAttach(func() { s.publish(s.Cfg.ReqTimeout()) }) |
| 590 | s.goAttach(s.purgeFile) |
| 591 | s.goAttach(func() { monitorFileDescriptor(s.stopping) }) |
| 592 | s.goAttach(s.monitorVersions) |
| 593 | s.goAttach(s.linearizableReadLoop) |
| 594 | s.goAttach(s.monitorKVHash) |
| 595 | } |
| 596 | |
| 597 | // start prepares and starts server in a new goroutine. It is no longer safe to |
| 598 | // modify a server's fields after it has been sent to Start. |
| 599 | // This function is just used for testing. |
| 600 | func (s *EtcdServer) start() { |
| 601 | if s.Cfg.SnapCount == 0 { |
| 602 | plog.Infof("set snapshot count to default %d", DefaultSnapCount) |
| 603 | s.Cfg.SnapCount = DefaultSnapCount |
| 604 | } |
| 605 | s.w = wait.New() |
| 606 | s.applyWait = wait.NewTimeList() |
| 607 | s.done = make(chan struct{}) |
| 608 | s.stop = make(chan struct{}) |
| 609 | s.stopping = make(chan struct{}) |
| 610 | s.ctx, s.cancel = context.WithCancel(context.Background()) |
| 611 | s.readwaitc = make(chan struct{}, 1) |
| 612 | s.readNotifier = newNotifier() |
| 613 | s.leaderChanged = make(chan struct{}) |
| 614 | if s.ClusterVersion() != nil { |
| 615 | plog.Infof("starting server... [version: %v, cluster version: %v]", version.Version, version.Cluster(s.ClusterVersion().String())) |
| 616 | membership.ClusterVersionMetrics.With(prometheus.Labels{"cluster_version": version.Cluster(s.ClusterVersion().String())}).Set(1) |
| 617 | } else { |
| 618 | plog.Infof("starting server... [version: %v, cluster version: to_be_decided]", version.Version) |
| 619 | } |
| 620 | // TODO: if this is an empty log, writes all peer infos |
| 621 | // into the first entry |
| 622 | go s.run() |
| 623 | } |
| 624 | |
| 625 | func (s *EtcdServer) purgeFile() { |
| 626 | var dberrc, serrc, werrc <-chan error |
| 627 | var dbdonec, sdonec, wdonec <-chan struct{} |
| 628 | if s.Cfg.MaxSnapFiles > 0 { |
| 629 | dbdonec, dberrc = fileutil.PurgeFileWithDoneNotify(s.Cfg.SnapDir(), "snap.db", s.Cfg.MaxSnapFiles, purgeFileInterval, s.stopping) |
| 630 | sdonec, serrc = fileutil.PurgeFileWithDoneNotify(s.Cfg.SnapDir(), "snap", s.Cfg.MaxSnapFiles, purgeFileInterval, s.stopping) |
| 631 | } |
| 632 | if s.Cfg.MaxWALFiles > 0 { |
| 633 | wdonec, werrc = fileutil.PurgeFileWithDoneNotify(s.Cfg.WALDir(), "wal", s.Cfg.MaxWALFiles, purgeFileInterval, s.stopping) |
| 634 | } |
| 635 | select { |
| 636 | case e := <-dberrc: |
| 637 | plog.Fatalf("failed to purge snap db file %v", e) |
| 638 | case e := <-serrc: |
| 639 | plog.Fatalf("failed to purge snap file %v", e) |
| 640 | case e := <-werrc: |
| 641 | plog.Fatalf("failed to purge wal file %v", e) |
| 642 | case <-s.stopping: |
| 643 | if dbdonec != nil { |
| 644 | <-dbdonec |
| 645 | } |
| 646 | if sdonec != nil { |
| 647 | <-sdonec |
| 648 | } |
| 649 | if wdonec != nil { |
| 650 | <-wdonec |
| 651 | } |
| 652 | return |
| 653 | } |
| 654 | } |
| 655 | |
| 656 | func (s *EtcdServer) ID() types.ID { return s.id } |
| 657 | |
| 658 | func (s *EtcdServer) Cluster() api.Cluster { return s.cluster } |
| 659 | |
| 660 | func (s *EtcdServer) ApplyWait() <-chan struct{} { return s.applyWait.Wait(s.getCommittedIndex()) } |
| 661 | |
| 662 | type ServerPeer interface { |
| 663 | ServerV2 |
| 664 | RaftHandler() http.Handler |
| 665 | LeaseHandler() http.Handler |
| 666 | } |
| 667 | |
| 668 | func (s *EtcdServer) LeaseHandler() http.Handler { |
| 669 | if s.lessor == nil { |
| 670 | return nil |
| 671 | } |
| 672 | return leasehttp.NewHandler(s.lessor, s.ApplyWait) |
| 673 | } |
| 674 | |
| 675 | func (s *EtcdServer) RaftHandler() http.Handler { return s.r.transport.Handler() } |
| 676 | |
| 677 | // Process takes a raft message and applies it to the server's raft state |
| 678 | // machine, respecting any timeout of the given context. |
| 679 | func (s *EtcdServer) Process(ctx context.Context, m raftpb.Message) error { |
| 680 | if s.cluster.IsIDRemoved(types.ID(m.From)) { |
| 681 | plog.Warningf("reject message from removed member %s", types.ID(m.From).String()) |
| 682 | return httptypes.NewHTTPError(http.StatusForbidden, "cannot process message from removed member") |
| 683 | } |
| 684 | if m.Type == raftpb.MsgApp { |
| 685 | s.stats.RecvAppendReq(types.ID(m.From).String(), m.Size()) |
| 686 | } |
| 687 | return s.r.Step(ctx, m) |
| 688 | } |
| 689 | |
| 690 | func (s *EtcdServer) IsIDRemoved(id uint64) bool { return s.cluster.IsIDRemoved(types.ID(id)) } |
| 691 | |
| 692 | func (s *EtcdServer) ReportUnreachable(id uint64) { s.r.ReportUnreachable(id) } |
| 693 | |
| 694 | // ReportSnapshot reports snapshot sent status to the raft state machine, |
| 695 | // and clears the used snapshot from the snapshot store. |
| 696 | func (s *EtcdServer) ReportSnapshot(id uint64, status raft.SnapshotStatus) { |
| 697 | s.r.ReportSnapshot(id, status) |
| 698 | } |
| 699 | |
| 700 | type etcdProgress struct { |
| 701 | confState raftpb.ConfState |
| 702 | snapi uint64 |
| 703 | appliedt uint64 |
| 704 | appliedi uint64 |
| 705 | } |
| 706 | |
| 707 | // raftReadyHandler contains a set of EtcdServer operations to be called by raftNode, |
| 708 | // and helps decouple state machine logic from Raft algorithms. |
| 709 | // TODO: add a state machine interface to apply the commit entries and do snapshot/recover |
| 710 | type raftReadyHandler struct { |
| 711 | updateLeadership func(newLeader bool) |
| 712 | updateCommittedIndex func(uint64) |
| 713 | } |
| 714 | |
| 715 | func (s *EtcdServer) run() { |
| 716 | sn, err := s.r.raftStorage.Snapshot() |
| 717 | if err != nil { |
| 718 | plog.Panicf("get snapshot from raft storage error: %v", err) |
| 719 | } |
| 720 | |
| 721 | // asynchronously accept apply packets, dispatch progress in-order |
| 722 | sched := schedule.NewFIFOScheduler() |
| 723 | |
| 724 | var ( |
| 725 | smu sync.RWMutex |
| 726 | syncC <-chan time.Time |
| 727 | ) |
| 728 | setSyncC := func(ch <-chan time.Time) { |
| 729 | smu.Lock() |
| 730 | syncC = ch |
| 731 | smu.Unlock() |
| 732 | } |
| 733 | getSyncC := func() (ch <-chan time.Time) { |
| 734 | smu.RLock() |
| 735 | ch = syncC |
| 736 | smu.RUnlock() |
| 737 | return |
| 738 | } |
| 739 | rh := &raftReadyHandler{ |
| 740 | updateLeadership: func(newLeader bool) { |
| 741 | if !s.isLeader() { |
| 742 | if s.lessor != nil { |
| 743 | s.lessor.Demote() |
| 744 | } |
| 745 | if s.compactor != nil { |
| 746 | s.compactor.Pause() |
| 747 | } |
| 748 | setSyncC(nil) |
| 749 | } else { |
| 750 | if newLeader { |
| 751 | t := time.Now() |
| 752 | s.leadTimeMu.Lock() |
| 753 | s.leadElectedTime = t |
| 754 | s.leadTimeMu.Unlock() |
| 755 | } |
| 756 | setSyncC(s.SyncTicker.C) |
| 757 | if s.compactor != nil { |
| 758 | s.compactor.Resume() |
| 759 | } |
| 760 | } |
| 761 | if newLeader { |
| 762 | select { |
| 763 | case s.leaderChanged <- struct{}{}: |
| 764 | default: |
| 765 | } |
| 766 | s.leaderChangedMu.Lock() |
| 767 | lc := s.leaderChanged |
| 768 | s.leaderChanged = make(chan struct{}) |
| 769 | s.leaderChangedMu.Unlock() |
| 770 | close(lc) |
| 771 | } |
| 772 | |
| 773 | // TODO: remove the nil checking |
| 774 | // current test utility does not provide the stats |
| 775 | if s.stats != nil { |
| 776 | s.stats.BecomeLeader() |
| 777 | } |
| 778 | }, |
| 779 | updateCommittedIndex: func(ci uint64) { |
| 780 | cci := s.getCommittedIndex() |
| 781 | if ci > cci { |
| 782 | s.setCommittedIndex(ci) |
| 783 | } |
| 784 | }, |
| 785 | } |
| 786 | s.r.start(rh) |
| 787 | |
| 788 | ep := etcdProgress{ |
| 789 | confState: sn.Metadata.ConfState, |
| 790 | snapi: sn.Metadata.Index, |
| 791 | appliedt: sn.Metadata.Term, |
| 792 | appliedi: sn.Metadata.Index, |
| 793 | } |
| 794 | |
| 795 | defer func() { |
| 796 | s.wgMu.Lock() // block concurrent waitgroup adds in goAttach while stopping |
| 797 | close(s.stopping) |
| 798 | s.wgMu.Unlock() |
| 799 | s.cancel() |
| 800 | |
| 801 | sched.Stop() |
| 802 | |
| 803 | // wait for gouroutines before closing raft so wal stays open |
| 804 | s.wg.Wait() |
| 805 | |
| 806 | s.SyncTicker.Stop() |
| 807 | |
| 808 | // must stop raft after scheduler-- etcdserver can leak rafthttp pipelines |
| 809 | // by adding a peer after raft stops the transport |
| 810 | s.r.stop() |
| 811 | |
| 812 | // kv, lessor and backend can be nil if running without v3 enabled |
| 813 | // or running unit tests. |
| 814 | if s.lessor != nil { |
| 815 | s.lessor.Stop() |
| 816 | } |
| 817 | if s.kv != nil { |
| 818 | s.kv.Close() |
| 819 | } |
| 820 | if s.authStore != nil { |
| 821 | s.authStore.Close() |
| 822 | } |
| 823 | if s.be != nil { |
| 824 | s.be.Close() |
| 825 | } |
| 826 | if s.compactor != nil { |
| 827 | s.compactor.Stop() |
| 828 | } |
| 829 | close(s.done) |
| 830 | }() |
| 831 | |
| 832 | var expiredLeaseC <-chan []*lease.Lease |
| 833 | if s.lessor != nil { |
| 834 | expiredLeaseC = s.lessor.ExpiredLeasesC() |
| 835 | } |
| 836 | |
| 837 | for { |
| 838 | select { |
| 839 | case ap := <-s.r.apply(): |
| 840 | f := func(context.Context) { s.applyAll(&ep, &ap) } |
| 841 | sched.Schedule(f) |
| 842 | case leases := <-expiredLeaseC: |
| 843 | s.goAttach(func() { |
| 844 | // Increases throughput of expired leases deletion process through parallelization |
| 845 | c := make(chan struct{}, maxPendingRevokes) |
| 846 | for _, lease := range leases { |
| 847 | select { |
| 848 | case c <- struct{}{}: |
| 849 | case <-s.stopping: |
| 850 | return |
| 851 | } |
| 852 | lid := lease.ID |
| 853 | s.goAttach(func() { |
| 854 | ctx := s.authStore.WithRoot(s.ctx) |
| 855 | _, lerr := s.LeaseRevoke(ctx, &pb.LeaseRevokeRequest{ID: int64(lid)}) |
| 856 | if lerr == nil { |
| 857 | leaseExpired.Inc() |
| 858 | } else { |
| 859 | plog.Warningf("failed to revoke %016x (%q)", lid, lerr.Error()) |
| 860 | } |
| 861 | |
| 862 | <-c |
| 863 | }) |
| 864 | } |
| 865 | }) |
| 866 | case err := <-s.errorc: |
| 867 | plog.Errorf("%s", err) |
| 868 | plog.Infof("the data-dir used by this member must be removed.") |
| 869 | return |
| 870 | case <-getSyncC(): |
| 871 | if s.store.HasTTLKeys() { |
| 872 | s.sync(s.Cfg.ReqTimeout()) |
| 873 | } |
| 874 | case <-s.stop: |
| 875 | return |
| 876 | } |
| 877 | } |
| 878 | } |
| 879 | |
| 880 | func (s *EtcdServer) leaderChangedNotify() <-chan struct{} { |
| 881 | s.leaderChangedMu.RLock() |
| 882 | defer s.leaderChangedMu.RUnlock() |
| 883 | return s.leaderChanged |
| 884 | } |
| 885 | |
| 886 | func (s *EtcdServer) applyAll(ep *etcdProgress, apply *apply) { |
| 887 | s.applySnapshot(ep, apply) |
| 888 | s.applyEntries(ep, apply) |
| 889 | |
| 890 | proposalsApplied.Set(float64(ep.appliedi)) |
| 891 | s.applyWait.Trigger(ep.appliedi) |
| 892 | // wait for the raft routine to finish the disk writes before triggering a |
| 893 | // snapshot. or applied index might be greater than the last index in raft |
| 894 | // storage, since the raft routine might be slower than apply routine. |
| 895 | <-apply.notifyc |
| 896 | |
| 897 | s.triggerSnapshot(ep) |
| 898 | select { |
| 899 | // snapshot requested via send() |
| 900 | case m := <-s.r.msgSnapC: |
| 901 | merged := s.createMergedSnapshotMessage(m, ep.appliedt, ep.appliedi, ep.confState) |
| 902 | s.sendMergedSnap(merged) |
| 903 | default: |
| 904 | } |
| 905 | } |
| 906 | |
| 907 | func (s *EtcdServer) applySnapshot(ep *etcdProgress, apply *apply) { |
| 908 | if raft.IsEmptySnap(apply.snapshot) { |
| 909 | return |
| 910 | } |
| 911 | applySnapshotInProgress.Inc() |
| 912 | plog.Infof("applying snapshot at index %d...", ep.snapi) |
| 913 | defer func() { |
| 914 | plog.Infof("finished applying incoming snapshot at index %d", ep.snapi) |
| 915 | applySnapshotInProgress.Dec() |
| 916 | }() |
| 917 | |
| 918 | if apply.snapshot.Metadata.Index <= ep.appliedi { |
| 919 | plog.Panicf("snapshot index [%d] should > appliedi[%d] + 1", |
| 920 | apply.snapshot.Metadata.Index, ep.appliedi) |
| 921 | } |
| 922 | |
| 923 | // wait for raftNode to persist snapshot onto the disk |
| 924 | <-apply.notifyc |
| 925 | |
| 926 | newbe, err := openSnapshotBackend(s.Cfg, s.snapshotter, apply.snapshot) |
| 927 | if err != nil { |
| 928 | plog.Panic(err) |
| 929 | } |
| 930 | |
| 931 | // always recover lessor before kv. When we recover the mvcc.KV it will reattach keys to its leases. |
| 932 | // If we recover mvcc.KV first, it will attach the keys to the wrong lessor before it recovers. |
| 933 | if s.lessor != nil { |
| 934 | plog.Info("recovering lessor...") |
| 935 | s.lessor.Recover(newbe, func() lease.TxnDelete { return s.kv.Write() }) |
| 936 | plog.Info("finished recovering lessor") |
| 937 | } |
| 938 | |
| 939 | plog.Info("restoring mvcc store...") |
| 940 | |
| 941 | if err := s.kv.Restore(newbe); err != nil { |
| 942 | plog.Panicf("restore KV error: %v", err) |
| 943 | } |
| 944 | s.consistIndex.setConsistentIndex(s.kv.ConsistentIndex()) |
| 945 | |
| 946 | plog.Info("finished restoring mvcc store") |
| 947 | |
| 948 | // Closing old backend might block until all the txns |
| 949 | // on the backend are finished. |
| 950 | // We do not want to wait on closing the old backend. |
| 951 | s.bemu.Lock() |
| 952 | oldbe := s.be |
| 953 | go func() { |
| 954 | plog.Info("closing old backend...") |
| 955 | defer plog.Info("finished closing old backend") |
| 956 | |
| 957 | if err := oldbe.Close(); err != nil { |
| 958 | plog.Panicf("close backend error: %v", err) |
| 959 | } |
| 960 | }() |
| 961 | |
| 962 | s.be = newbe |
| 963 | s.bemu.Unlock() |
| 964 | |
| 965 | plog.Info("recovering alarms...") |
| 966 | if err := s.restoreAlarms(); err != nil { |
| 967 | plog.Panicf("restore alarms error: %v", err) |
| 968 | } |
| 969 | plog.Info("finished recovering alarms") |
| 970 | |
| 971 | if s.authStore != nil { |
| 972 | plog.Info("recovering auth store...") |
| 973 | s.authStore.Recover(newbe) |
| 974 | plog.Info("finished recovering auth store") |
| 975 | } |
| 976 | |
| 977 | plog.Info("recovering store v2...") |
| 978 | if err := s.store.Recovery(apply.snapshot.Data); err != nil { |
| 979 | plog.Panicf("recovery store error: %v", err) |
| 980 | } |
| 981 | plog.Info("finished recovering store v2") |
| 982 | |
| 983 | s.cluster.SetBackend(s.be) |
| 984 | plog.Info("recovering cluster configuration...") |
| 985 | s.cluster.Recover(api.UpdateCapability) |
| 986 | plog.Info("finished recovering cluster configuration") |
| 987 | |
| 988 | plog.Info("removing old peers from network...") |
| 989 | // recover raft transport |
| 990 | s.r.transport.RemoveAllPeers() |
| 991 | plog.Info("finished removing old peers from network") |
| 992 | |
| 993 | plog.Info("adding peers from new cluster configuration into network...") |
| 994 | for _, m := range s.cluster.Members() { |
| 995 | if m.ID == s.ID() { |
| 996 | continue |
| 997 | } |
| 998 | s.r.transport.AddPeer(m.ID, m.PeerURLs) |
| 999 | } |
| 1000 | plog.Info("finished adding peers from new cluster configuration into network...") |
| 1001 | |
| 1002 | ep.appliedt = apply.snapshot.Metadata.Term |
| 1003 | ep.appliedi = apply.snapshot.Metadata.Index |
| 1004 | ep.snapi = ep.appliedi |
| 1005 | ep.confState = apply.snapshot.Metadata.ConfState |
| 1006 | } |
| 1007 | |
| 1008 | func (s *EtcdServer) applyEntries(ep *etcdProgress, apply *apply) { |
| 1009 | if len(apply.entries) == 0 { |
| 1010 | return |
| 1011 | } |
| 1012 | firsti := apply.entries[0].Index |
| 1013 | if firsti > ep.appliedi+1 { |
| 1014 | plog.Panicf("first index of committed entry[%d] should <= appliedi[%d] + 1", firsti, ep.appliedi) |
| 1015 | } |
| 1016 | var ents []raftpb.Entry |
| 1017 | if ep.appliedi+1-firsti < uint64(len(apply.entries)) { |
| 1018 | ents = apply.entries[ep.appliedi+1-firsti:] |
| 1019 | } |
| 1020 | if len(ents) == 0 { |
| 1021 | return |
| 1022 | } |
| 1023 | var shouldstop bool |
| 1024 | if ep.appliedt, ep.appliedi, shouldstop = s.apply(ents, &ep.confState); shouldstop { |
| 1025 | go s.stopWithDelay(10*100*time.Millisecond, fmt.Errorf("the member has been permanently removed from the cluster")) |
| 1026 | } |
| 1027 | } |
| 1028 | |
| 1029 | func (s *EtcdServer) triggerSnapshot(ep *etcdProgress) { |
| 1030 | if ep.appliedi-ep.snapi <= s.Cfg.SnapCount { |
| 1031 | return |
| 1032 | } |
| 1033 | |
| 1034 | plog.Infof("start to snapshot (applied: %d, lastsnap: %d)", ep.appliedi, ep.snapi) |
| 1035 | s.snapshot(ep.appliedi, ep.confState) |
| 1036 | ep.snapi = ep.appliedi |
| 1037 | } |
| 1038 | |
| 1039 | func (s *EtcdServer) isMultiNode() bool { |
| 1040 | return s.cluster != nil && len(s.cluster.MemberIDs()) > 1 |
| 1041 | } |
| 1042 | |
| 1043 | func (s *EtcdServer) isLeader() bool { |
| 1044 | return uint64(s.ID()) == s.Lead() |
| 1045 | } |
| 1046 | |
| 1047 | // MoveLeader transfers the leader to the given transferee. |
| 1048 | func (s *EtcdServer) MoveLeader(ctx context.Context, lead, transferee uint64) error { |
| 1049 | now := time.Now() |
| 1050 | interval := time.Duration(s.Cfg.TickMs) * time.Millisecond |
| 1051 | |
| 1052 | plog.Infof("%s starts leadership transfer from %s to %s", s.ID(), types.ID(lead), types.ID(transferee)) |
| 1053 | s.r.TransferLeadership(ctx, lead, transferee) |
| 1054 | for s.Lead() != transferee { |
| 1055 | select { |
| 1056 | case <-ctx.Done(): // time out |
| 1057 | return ErrTimeoutLeaderTransfer |
| 1058 | case <-time.After(interval): |
| 1059 | } |
| 1060 | } |
| 1061 | |
| 1062 | // TODO: drain all requests, or drop all messages to the old leader |
| 1063 | |
| 1064 | plog.Infof("%s finished leadership transfer from %s to %s (took %v)", s.ID(), types.ID(lead), types.ID(transferee), time.Since(now)) |
| 1065 | return nil |
| 1066 | } |
| 1067 | |
| 1068 | // TransferLeadership transfers the leader to the chosen transferee. |
| 1069 | func (s *EtcdServer) TransferLeadership() error { |
| 1070 | if !s.isLeader() { |
| 1071 | plog.Printf("skipped leadership transfer for stopping non-leader member") |
| 1072 | return nil |
| 1073 | } |
| 1074 | |
| 1075 | if !s.isMultiNode() { |
| 1076 | plog.Printf("skipped leadership transfer for single member cluster") |
| 1077 | return nil |
| 1078 | } |
| 1079 | |
| 1080 | transferee, ok := longestConnected(s.r.transport, s.cluster.MemberIDs()) |
| 1081 | if !ok { |
| 1082 | return ErrUnhealthy |
| 1083 | } |
| 1084 | |
| 1085 | tm := s.Cfg.ReqTimeout() |
| 1086 | ctx, cancel := context.WithTimeout(s.ctx, tm) |
| 1087 | err := s.MoveLeader(ctx, s.Lead(), uint64(transferee)) |
| 1088 | cancel() |
| 1089 | return err |
| 1090 | } |
| 1091 | |
| 1092 | // HardStop stops the server without coordination with other members in the cluster. |
| 1093 | func (s *EtcdServer) HardStop() { |
| 1094 | select { |
| 1095 | case s.stop <- struct{}{}: |
| 1096 | case <-s.done: |
| 1097 | return |
| 1098 | } |
| 1099 | <-s.done |
| 1100 | } |
| 1101 | |
| 1102 | // Stop stops the server gracefully, and shuts down the running goroutine. |
| 1103 | // Stop should be called after a Start(s), otherwise it will block forever. |
| 1104 | // When stopping leader, Stop transfers its leadership to one of its peers |
| 1105 | // before stopping the server. |
| 1106 | // Stop terminates the Server and performs any necessary finalization. |
| 1107 | // Do and Process cannot be called after Stop has been invoked. |
| 1108 | func (s *EtcdServer) Stop() { |
| 1109 | if err := s.TransferLeadership(); err != nil { |
| 1110 | plog.Warningf("%s failed to transfer leadership (%v)", s.ID(), err) |
| 1111 | } |
| 1112 | s.HardStop() |
| 1113 | } |
| 1114 | |
| 1115 | // ReadyNotify returns a channel that will be closed when the server |
| 1116 | // is ready to serve client requests |
| 1117 | func (s *EtcdServer) ReadyNotify() <-chan struct{} { return s.readych } |
| 1118 | |
| 1119 | func (s *EtcdServer) stopWithDelay(d time.Duration, err error) { |
| 1120 | select { |
| 1121 | case <-time.After(d): |
| 1122 | case <-s.done: |
| 1123 | } |
| 1124 | select { |
| 1125 | case s.errorc <- err: |
| 1126 | default: |
| 1127 | } |
| 1128 | } |
| 1129 | |
| 1130 | // StopNotify returns a channel that receives a empty struct |
| 1131 | // when the server is stopped. |
| 1132 | func (s *EtcdServer) StopNotify() <-chan struct{} { return s.done } |
| 1133 | |
| 1134 | func (s *EtcdServer) SelfStats() []byte { return s.stats.JSON() } |
| 1135 | |
| 1136 | func (s *EtcdServer) LeaderStats() []byte { |
| 1137 | lead := atomic.LoadUint64(&s.r.lead) |
| 1138 | if lead != uint64(s.id) { |
| 1139 | return nil |
| 1140 | } |
| 1141 | return s.lstats.JSON() |
| 1142 | } |
| 1143 | |
| 1144 | func (s *EtcdServer) StoreStats() []byte { return s.store.JsonStats() } |
| 1145 | |
| 1146 | func (s *EtcdServer) checkMembershipOperationPermission(ctx context.Context) error { |
| 1147 | if s.authStore == nil { |
| 1148 | // In the context of ordinary etcd process, s.authStore will never be nil. |
| 1149 | // This branch is for handling cases in server_test.go |
| 1150 | return nil |
| 1151 | } |
| 1152 | |
| 1153 | // Note that this permission check is done in the API layer, |
| 1154 | // so TOCTOU problem can be caused potentially in a schedule like this: |
| 1155 | // update membership with user A -> revoke root role of A -> apply membership change |
| 1156 | // in the state machine layer |
| 1157 | // However, both of membership change and role management requires the root privilege. |
| 1158 | // So careful operation by admins can prevent the problem. |
| 1159 | authInfo, err := s.AuthInfoFromCtx(ctx) |
| 1160 | if err != nil { |
| 1161 | return err |
| 1162 | } |
| 1163 | |
| 1164 | return s.AuthStore().IsAdminPermitted(authInfo) |
| 1165 | } |
| 1166 | |
| 1167 | func (s *EtcdServer) AddMember(ctx context.Context, memb membership.Member) ([]*membership.Member, error) { |
| 1168 | if err := s.checkMembershipOperationPermission(ctx); err != nil { |
| 1169 | return nil, err |
| 1170 | } |
| 1171 | |
| 1172 | if s.Cfg.StrictReconfigCheck { |
| 1173 | // by default StrictReconfigCheck is enabled; reject new members if unhealthy |
| 1174 | if !s.cluster.IsReadyToAddNewMember() { |
| 1175 | plog.Warningf("not enough started members, rejecting member add %+v", memb) |
| 1176 | return nil, ErrNotEnoughStartedMembers |
| 1177 | } |
| 1178 | if !isConnectedFullySince(s.r.transport, time.Now().Add(-HealthInterval), s.ID(), s.cluster.Members()) { |
| 1179 | plog.Warningf("not healthy for reconfigure, rejecting member add %+v", memb) |
| 1180 | return nil, ErrUnhealthy |
| 1181 | } |
| 1182 | } |
| 1183 | |
| 1184 | // TODO: move Member to protobuf type |
| 1185 | b, err := json.Marshal(memb) |
| 1186 | if err != nil { |
| 1187 | return nil, err |
| 1188 | } |
| 1189 | cc := raftpb.ConfChange{ |
| 1190 | Type: raftpb.ConfChangeAddNode, |
| 1191 | NodeID: uint64(memb.ID), |
| 1192 | Context: b, |
| 1193 | } |
| 1194 | return s.configure(ctx, cc) |
| 1195 | } |
| 1196 | |
| 1197 | func (s *EtcdServer) RemoveMember(ctx context.Context, id uint64) ([]*membership.Member, error) { |
| 1198 | if err := s.checkMembershipOperationPermission(ctx); err != nil { |
| 1199 | return nil, err |
| 1200 | } |
| 1201 | |
| 1202 | // by default StrictReconfigCheck is enabled; reject removal if leads to quorum loss |
| 1203 | if err := s.mayRemoveMember(types.ID(id)); err != nil { |
| 1204 | return nil, err |
| 1205 | } |
| 1206 | |
| 1207 | cc := raftpb.ConfChange{ |
| 1208 | Type: raftpb.ConfChangeRemoveNode, |
| 1209 | NodeID: id, |
| 1210 | } |
| 1211 | return s.configure(ctx, cc) |
| 1212 | } |
| 1213 | |
| 1214 | func (s *EtcdServer) mayRemoveMember(id types.ID) error { |
| 1215 | if !s.Cfg.StrictReconfigCheck { |
| 1216 | return nil |
| 1217 | } |
| 1218 | |
| 1219 | if !s.cluster.IsReadyToRemoveMember(uint64(id)) { |
| 1220 | plog.Warningf("not enough started members, rejecting remove member %s", id) |
| 1221 | return ErrNotEnoughStartedMembers |
| 1222 | } |
| 1223 | |
| 1224 | // downed member is safe to remove since it's not part of the active quorum |
| 1225 | if t := s.r.transport.ActiveSince(id); id != s.ID() && t.IsZero() { |
| 1226 | return nil |
| 1227 | } |
| 1228 | |
| 1229 | // protect quorum if some members are down |
| 1230 | m := s.cluster.Members() |
| 1231 | active := numConnectedSince(s.r.transport, time.Now().Add(-HealthInterval), s.ID(), m) |
| 1232 | if (active - 1) < 1+((len(m)-1)/2) { |
| 1233 | plog.Warningf("reconfigure breaks active quorum, rejecting remove member %s", id) |
| 1234 | return ErrUnhealthy |
| 1235 | } |
| 1236 | |
| 1237 | return nil |
| 1238 | } |
| 1239 | |
| 1240 | func (s *EtcdServer) UpdateMember(ctx context.Context, memb membership.Member) ([]*membership.Member, error) { |
| 1241 | b, merr := json.Marshal(memb) |
| 1242 | if merr != nil { |
| 1243 | return nil, merr |
| 1244 | } |
| 1245 | |
| 1246 | if err := s.checkMembershipOperationPermission(ctx); err != nil { |
| 1247 | return nil, err |
| 1248 | } |
| 1249 | cc := raftpb.ConfChange{ |
| 1250 | Type: raftpb.ConfChangeUpdateNode, |
| 1251 | NodeID: uint64(memb.ID), |
| 1252 | Context: b, |
| 1253 | } |
| 1254 | return s.configure(ctx, cc) |
| 1255 | } |
| 1256 | |
| 1257 | // Implement the RaftTimer interface |
| 1258 | |
| 1259 | func (s *EtcdServer) Index() uint64 { return atomic.LoadUint64(&s.r.index) } |
| 1260 | |
| 1261 | func (s *EtcdServer) Term() uint64 { return atomic.LoadUint64(&s.r.term) } |
| 1262 | |
| 1263 | // Lead is only for testing purposes. |
| 1264 | // TODO: add Raft server interface to expose raft related info: |
| 1265 | // Index, Term, Lead, Committed, Applied, LastIndex, etc. |
| 1266 | func (s *EtcdServer) Lead() uint64 { return atomic.LoadUint64(&s.r.lead) } |
| 1267 | |
| 1268 | func (s *EtcdServer) Leader() types.ID { return types.ID(s.Lead()) } |
| 1269 | |
| 1270 | type confChangeResponse struct { |
| 1271 | membs []*membership.Member |
| 1272 | err error |
| 1273 | } |
| 1274 | |
| 1275 | // configure sends a configuration change through consensus and |
| 1276 | // then waits for it to be applied to the server. It |
| 1277 | // will block until the change is performed or there is an error. |
| 1278 | func (s *EtcdServer) configure(ctx context.Context, cc raftpb.ConfChange) ([]*membership.Member, error) { |
| 1279 | cc.ID = s.reqIDGen.Next() |
| 1280 | ch := s.w.Register(cc.ID) |
| 1281 | start := time.Now() |
| 1282 | if err := s.r.ProposeConfChange(ctx, cc); err != nil { |
| 1283 | s.w.Trigger(cc.ID, nil) |
| 1284 | return nil, err |
| 1285 | } |
| 1286 | select { |
| 1287 | case x := <-ch: |
| 1288 | if x == nil { |
| 1289 | plog.Panicf("configure trigger value should never be nil") |
| 1290 | } |
| 1291 | resp := x.(*confChangeResponse) |
| 1292 | return resp.membs, resp.err |
| 1293 | case <-ctx.Done(): |
| 1294 | s.w.Trigger(cc.ID, nil) // GC wait |
| 1295 | return nil, s.parseProposeCtxErr(ctx.Err(), start) |
| 1296 | case <-s.stopping: |
| 1297 | return nil, ErrStopped |
| 1298 | } |
| 1299 | } |
| 1300 | |
| 1301 | // sync proposes a SYNC request and is non-blocking. |
| 1302 | // This makes no guarantee that the request will be proposed or performed. |
| 1303 | // The request will be canceled after the given timeout. |
| 1304 | func (s *EtcdServer) sync(timeout time.Duration) { |
| 1305 | req := pb.Request{ |
| 1306 | Method: "SYNC", |
| 1307 | ID: s.reqIDGen.Next(), |
| 1308 | Time: time.Now().UnixNano(), |
| 1309 | } |
| 1310 | data := pbutil.MustMarshal(&req) |
| 1311 | // There is no promise that node has leader when do SYNC request, |
| 1312 | // so it uses goroutine to propose. |
| 1313 | ctx, cancel := context.WithTimeout(s.ctx, timeout) |
| 1314 | s.goAttach(func() { |
| 1315 | s.r.Propose(ctx, data) |
| 1316 | cancel() |
| 1317 | }) |
| 1318 | } |
| 1319 | |
| 1320 | // publish registers server information into the cluster. The information |
| 1321 | // is the JSON representation of this server's member struct, updated with the |
| 1322 | // static clientURLs of the server. |
| 1323 | // The function keeps attempting to register until it succeeds, |
| 1324 | // or its server is stopped. |
| 1325 | func (s *EtcdServer) publish(timeout time.Duration) { |
| 1326 | b, err := json.Marshal(s.attributes) |
| 1327 | if err != nil { |
| 1328 | plog.Panicf("json marshal error: %v", err) |
| 1329 | return |
| 1330 | } |
| 1331 | req := pb.Request{ |
| 1332 | Method: "PUT", |
| 1333 | Path: membership.MemberAttributesStorePath(s.id), |
| 1334 | Val: string(b), |
| 1335 | } |
| 1336 | |
| 1337 | for { |
| 1338 | ctx, cancel := context.WithTimeout(s.ctx, timeout) |
| 1339 | _, err := s.Do(ctx, req) |
| 1340 | cancel() |
| 1341 | switch err { |
| 1342 | case nil: |
| 1343 | close(s.readych) |
| 1344 | plog.Infof("published %+v to cluster %s", s.attributes, s.cluster.ID()) |
| 1345 | return |
| 1346 | case ErrStopped: |
| 1347 | plog.Infof("aborting publish because server is stopped") |
| 1348 | return |
| 1349 | default: |
| 1350 | plog.Errorf("publish error: %v", err) |
| 1351 | } |
| 1352 | } |
| 1353 | } |
| 1354 | |
| 1355 | func (s *EtcdServer) sendMergedSnap(merged snap.Message) { |
| 1356 | atomic.AddInt64(&s.inflightSnapshots, 1) |
| 1357 | |
| 1358 | s.r.transport.SendSnapshot(merged) |
| 1359 | s.goAttach(func() { |
| 1360 | select { |
| 1361 | case ok := <-merged.CloseNotify(): |
| 1362 | // delay releasing inflight snapshot for another 30 seconds to |
| 1363 | // block log compaction. |
| 1364 | // If the follower still fails to catch up, it is probably just too slow |
| 1365 | // to catch up. We cannot avoid the snapshot cycle anyway. |
| 1366 | if ok { |
| 1367 | select { |
| 1368 | case <-time.After(releaseDelayAfterSnapshot): |
| 1369 | case <-s.stopping: |
| 1370 | } |
| 1371 | } |
| 1372 | atomic.AddInt64(&s.inflightSnapshots, -1) |
| 1373 | case <-s.stopping: |
| 1374 | return |
| 1375 | } |
| 1376 | }) |
| 1377 | } |
| 1378 | |
| 1379 | // apply takes entries received from Raft (after it has been committed) and |
| 1380 | // applies them to the current state of the EtcdServer. |
| 1381 | // The given entries should not be empty. |
| 1382 | func (s *EtcdServer) apply(es []raftpb.Entry, confState *raftpb.ConfState) (appliedt uint64, appliedi uint64, shouldStop bool) { |
| 1383 | for i := range es { |
| 1384 | e := es[i] |
| 1385 | switch e.Type { |
| 1386 | case raftpb.EntryNormal: |
| 1387 | s.applyEntryNormal(&e) |
| 1388 | case raftpb.EntryConfChange: |
| 1389 | // set the consistent index of current executing entry |
| 1390 | if e.Index > s.consistIndex.ConsistentIndex() { |
| 1391 | s.consistIndex.setConsistentIndex(e.Index) |
| 1392 | } |
| 1393 | var cc raftpb.ConfChange |
| 1394 | pbutil.MustUnmarshal(&cc, e.Data) |
| 1395 | removedSelf, err := s.applyConfChange(cc, confState) |
| 1396 | s.setAppliedIndex(e.Index) |
| 1397 | shouldStop = shouldStop || removedSelf |
| 1398 | s.w.Trigger(cc.ID, &confChangeResponse{s.cluster.Members(), err}) |
| 1399 | default: |
| 1400 | plog.Panicf("entry type should be either EntryNormal or EntryConfChange") |
| 1401 | } |
| 1402 | atomic.StoreUint64(&s.r.index, e.Index) |
| 1403 | atomic.StoreUint64(&s.r.term, e.Term) |
| 1404 | appliedt = e.Term |
| 1405 | appliedi = e.Index |
| 1406 | } |
| 1407 | return appliedt, appliedi, shouldStop |
| 1408 | } |
| 1409 | |
| 1410 | // applyEntryNormal apples an EntryNormal type raftpb request to the EtcdServer |
| 1411 | func (s *EtcdServer) applyEntryNormal(e *raftpb.Entry) { |
| 1412 | shouldApplyV3 := false |
| 1413 | if e.Index > s.consistIndex.ConsistentIndex() { |
| 1414 | // set the consistent index of current executing entry |
| 1415 | s.consistIndex.setConsistentIndex(e.Index) |
| 1416 | shouldApplyV3 = true |
| 1417 | } |
| 1418 | defer s.setAppliedIndex(e.Index) |
| 1419 | |
| 1420 | // raft state machine may generate noop entry when leader confirmation. |
| 1421 | // skip it in advance to avoid some potential bug in the future |
| 1422 | if len(e.Data) == 0 { |
| 1423 | select { |
| 1424 | case s.forceVersionC <- struct{}{}: |
| 1425 | default: |
| 1426 | } |
| 1427 | // promote lessor when the local member is leader and finished |
| 1428 | // applying all entries from the last term. |
| 1429 | if s.isLeader() { |
| 1430 | s.lessor.Promote(s.Cfg.electionTimeout()) |
| 1431 | } |
| 1432 | return |
| 1433 | } |
| 1434 | |
| 1435 | var raftReq pb.InternalRaftRequest |
| 1436 | if !pbutil.MaybeUnmarshal(&raftReq, e.Data) { // backward compatible |
| 1437 | var r pb.Request |
| 1438 | rp := &r |
| 1439 | pbutil.MustUnmarshal(rp, e.Data) |
| 1440 | s.w.Trigger(r.ID, s.applyV2Request((*RequestV2)(rp))) |
| 1441 | return |
| 1442 | } |
| 1443 | if raftReq.V2 != nil { |
| 1444 | req := (*RequestV2)(raftReq.V2) |
| 1445 | s.w.Trigger(req.ID, s.applyV2Request(req)) |
| 1446 | return |
| 1447 | } |
| 1448 | |
| 1449 | // do not re-apply applied entries. |
| 1450 | if !shouldApplyV3 { |
| 1451 | return |
| 1452 | } |
| 1453 | |
| 1454 | id := raftReq.ID |
| 1455 | if id == 0 { |
| 1456 | id = raftReq.Header.ID |
| 1457 | } |
| 1458 | |
| 1459 | var ar *applyResult |
| 1460 | needResult := s.w.IsRegistered(id) |
| 1461 | if needResult || !noSideEffect(&raftReq) { |
| 1462 | if !needResult && raftReq.Txn != nil { |
| 1463 | removeNeedlessRangeReqs(raftReq.Txn) |
| 1464 | } |
| 1465 | ar = s.applyV3.Apply(&raftReq) |
| 1466 | } |
| 1467 | |
| 1468 | if ar == nil { |
| 1469 | return |
| 1470 | } |
| 1471 | |
| 1472 | if ar.err != ErrNoSpace || len(s.alarmStore.Get(pb.AlarmType_NOSPACE)) > 0 { |
| 1473 | s.w.Trigger(id, ar) |
| 1474 | return |
| 1475 | } |
| 1476 | |
| 1477 | plog.Errorf("applying raft message exceeded backend quota") |
| 1478 | s.goAttach(func() { |
| 1479 | a := &pb.AlarmRequest{ |
| 1480 | MemberID: uint64(s.ID()), |
| 1481 | Action: pb.AlarmRequest_ACTIVATE, |
| 1482 | Alarm: pb.AlarmType_NOSPACE, |
| 1483 | } |
| 1484 | s.raftRequest(s.ctx, pb.InternalRaftRequest{Alarm: a}) |
| 1485 | s.w.Trigger(id, ar) |
| 1486 | }) |
| 1487 | } |
| 1488 | |
| 1489 | // applyConfChange applies a ConfChange to the server. It is only |
| 1490 | // invoked with a ConfChange that has already passed through Raft |
| 1491 | func (s *EtcdServer) applyConfChange(cc raftpb.ConfChange, confState *raftpb.ConfState) (bool, error) { |
| 1492 | if err := s.cluster.ValidateConfigurationChange(cc); err != nil { |
| 1493 | cc.NodeID = raft.None |
| 1494 | s.r.ApplyConfChange(cc) |
| 1495 | return false, err |
| 1496 | } |
| 1497 | *confState = *s.r.ApplyConfChange(cc) |
| 1498 | switch cc.Type { |
| 1499 | case raftpb.ConfChangeAddNode: |
| 1500 | m := new(membership.Member) |
| 1501 | if err := json.Unmarshal(cc.Context, m); err != nil { |
| 1502 | plog.Panicf("unmarshal member should never fail: %v", err) |
| 1503 | } |
| 1504 | if cc.NodeID != uint64(m.ID) { |
| 1505 | plog.Panicf("nodeID should always be equal to member ID") |
| 1506 | } |
| 1507 | s.cluster.AddMember(m) |
| 1508 | if m.ID != s.id { |
| 1509 | s.r.transport.AddPeer(m.ID, m.PeerURLs) |
| 1510 | } |
| 1511 | case raftpb.ConfChangeRemoveNode: |
| 1512 | id := types.ID(cc.NodeID) |
| 1513 | s.cluster.RemoveMember(id) |
| 1514 | if id == s.id { |
| 1515 | return true, nil |
| 1516 | } |
| 1517 | s.r.transport.RemovePeer(id) |
| 1518 | case raftpb.ConfChangeUpdateNode: |
| 1519 | m := new(membership.Member) |
| 1520 | if err := json.Unmarshal(cc.Context, m); err != nil { |
| 1521 | plog.Panicf("unmarshal member should never fail: %v", err) |
| 1522 | } |
| 1523 | if cc.NodeID != uint64(m.ID) { |
| 1524 | plog.Panicf("nodeID should always be equal to member ID") |
| 1525 | } |
| 1526 | s.cluster.UpdateRaftAttributes(m.ID, m.RaftAttributes) |
| 1527 | if m.ID != s.id { |
| 1528 | s.r.transport.UpdatePeer(m.ID, m.PeerURLs) |
| 1529 | } |
| 1530 | } |
| 1531 | return false, nil |
| 1532 | } |
| 1533 | |
| 1534 | // TODO: non-blocking snapshot |
| 1535 | func (s *EtcdServer) snapshot(snapi uint64, confState raftpb.ConfState) { |
| 1536 | clone := s.store.Clone() |
| 1537 | // commit kv to write metadata (for example: consistent index) to disk. |
| 1538 | // KV().commit() updates the consistent index in backend. |
| 1539 | // All operations that update consistent index must be called sequentially |
| 1540 | // from applyAll function. |
| 1541 | // So KV().Commit() cannot run in parallel with apply. It has to be called outside |
| 1542 | // the go routine created below. |
| 1543 | s.KV().Commit() |
| 1544 | |
| 1545 | s.goAttach(func() { |
| 1546 | d, err := clone.SaveNoCopy() |
| 1547 | // TODO: current store will never fail to do a snapshot |
| 1548 | // what should we do if the store might fail? |
| 1549 | if err != nil { |
| 1550 | plog.Panicf("store save should never fail: %v", err) |
| 1551 | } |
| 1552 | snap, err := s.r.raftStorage.CreateSnapshot(snapi, &confState, d) |
| 1553 | if err != nil { |
| 1554 | // the snapshot was done asynchronously with the progress of raft. |
| 1555 | // raft might have already got a newer snapshot. |
| 1556 | if err == raft.ErrSnapOutOfDate { |
| 1557 | return |
| 1558 | } |
| 1559 | plog.Panicf("unexpected create snapshot error %v", err) |
| 1560 | } |
| 1561 | // SaveSnap saves the snapshot and releases the locked wal files |
| 1562 | // to the snapshot index. |
| 1563 | if err = s.r.storage.SaveSnap(snap); err != nil { |
| 1564 | plog.Fatalf("save snapshot error: %v", err) |
| 1565 | } |
| 1566 | plog.Infof("saved snapshot at index %d", snap.Metadata.Index) |
| 1567 | |
| 1568 | if err = s.r.storage.Release(snap); err != nil { |
| 1569 | plog.Panicf("failed to release wal %v", err) |
| 1570 | } |
| 1571 | |
| 1572 | // When sending a snapshot, etcd will pause compaction. |
| 1573 | // After receives a snapshot, the slow follower needs to get all the entries right after |
| 1574 | // the snapshot sent to catch up. If we do not pause compaction, the log entries right after |
| 1575 | // the snapshot sent might already be compacted. It happens when the snapshot takes long time |
| 1576 | // to send and save. Pausing compaction avoids triggering a snapshot sending cycle. |
| 1577 | if atomic.LoadInt64(&s.inflightSnapshots) != 0 { |
| 1578 | plog.Infof("skip compaction since there is an inflight snapshot") |
| 1579 | return |
| 1580 | } |
| 1581 | |
| 1582 | // keep some in memory log entries for slow followers. |
| 1583 | compacti := uint64(1) |
| 1584 | if snapi > numberOfCatchUpEntries { |
| 1585 | compacti = snapi - numberOfCatchUpEntries |
| 1586 | } |
| 1587 | err = s.r.raftStorage.Compact(compacti) |
| 1588 | if err != nil { |
| 1589 | // the compaction was done asynchronously with the progress of raft. |
| 1590 | // raft log might already been compact. |
| 1591 | if err == raft.ErrCompacted { |
| 1592 | return |
| 1593 | } |
| 1594 | plog.Panicf("unexpected compaction error %v", err) |
| 1595 | } |
| 1596 | plog.Infof("compacted raft log at %d", compacti) |
| 1597 | }) |
| 1598 | } |
| 1599 | |
| 1600 | // CutPeer drops messages to the specified peer. |
| 1601 | func (s *EtcdServer) CutPeer(id types.ID) { |
| 1602 | tr, ok := s.r.transport.(*rafthttp.Transport) |
| 1603 | if ok { |
| 1604 | tr.CutPeer(id) |
| 1605 | } |
| 1606 | } |
| 1607 | |
| 1608 | // MendPeer recovers the message dropping behavior of the given peer. |
| 1609 | func (s *EtcdServer) MendPeer(id types.ID) { |
| 1610 | tr, ok := s.r.transport.(*rafthttp.Transport) |
| 1611 | if ok { |
| 1612 | tr.MendPeer(id) |
| 1613 | } |
| 1614 | } |
| 1615 | |
| 1616 | func (s *EtcdServer) PauseSending() { s.r.pauseSending() } |
| 1617 | |
| 1618 | func (s *EtcdServer) ResumeSending() { s.r.resumeSending() } |
| 1619 | |
| 1620 | func (s *EtcdServer) ClusterVersion() *semver.Version { |
| 1621 | if s.cluster == nil { |
| 1622 | return nil |
| 1623 | } |
| 1624 | return s.cluster.Version() |
| 1625 | } |
| 1626 | |
| 1627 | // monitorVersions checks the member's version every monitorVersionInterval. |
| 1628 | // It updates the cluster version if all members agrees on a higher one. |
| 1629 | // It prints out log if there is a member with a higher version than the |
| 1630 | // local version. |
| 1631 | func (s *EtcdServer) monitorVersions() { |
| 1632 | for { |
| 1633 | select { |
| 1634 | case <-s.forceVersionC: |
| 1635 | case <-time.After(monitorVersionInterval): |
| 1636 | case <-s.stopping: |
| 1637 | return |
| 1638 | } |
| 1639 | |
| 1640 | if s.Leader() != s.ID() { |
| 1641 | continue |
| 1642 | } |
| 1643 | |
| 1644 | v := decideClusterVersion(getVersions(s.cluster, s.id, s.peerRt)) |
| 1645 | if v != nil { |
| 1646 | // only keep major.minor version for comparison |
| 1647 | v = &semver.Version{ |
| 1648 | Major: v.Major, |
| 1649 | Minor: v.Minor, |
| 1650 | } |
| 1651 | } |
| 1652 | |
| 1653 | // if the current version is nil: |
| 1654 | // 1. use the decided version if possible |
| 1655 | // 2. or use the min cluster version |
| 1656 | if s.cluster.Version() == nil { |
| 1657 | verStr := version.MinClusterVersion |
| 1658 | if v != nil { |
| 1659 | verStr = v.String() |
| 1660 | } |
| 1661 | s.goAttach(func() { s.updateClusterVersion(verStr) }) |
| 1662 | continue |
| 1663 | } |
| 1664 | |
| 1665 | // update cluster version only if the decided version is greater than |
| 1666 | // the current cluster version |
| 1667 | if v != nil && s.cluster.Version().LessThan(*v) { |
| 1668 | s.goAttach(func() { s.updateClusterVersion(v.String()) }) |
| 1669 | } |
| 1670 | } |
| 1671 | } |
| 1672 | |
| 1673 | func (s *EtcdServer) updateClusterVersion(ver string) { |
| 1674 | if s.cluster.Version() == nil { |
| 1675 | plog.Infof("setting up the initial cluster version to %s", version.Cluster(ver)) |
| 1676 | } else { |
| 1677 | plog.Infof("updating the cluster version from %s to %s", version.Cluster(s.cluster.Version().String()), version.Cluster(ver)) |
| 1678 | } |
| 1679 | req := pb.Request{ |
| 1680 | Method: "PUT", |
| 1681 | Path: membership.StoreClusterVersionKey(), |
| 1682 | Val: ver, |
| 1683 | } |
| 1684 | ctx, cancel := context.WithTimeout(s.ctx, s.Cfg.ReqTimeout()) |
| 1685 | _, err := s.Do(ctx, req) |
| 1686 | cancel() |
| 1687 | switch err { |
| 1688 | case nil: |
| 1689 | return |
| 1690 | case ErrStopped: |
| 1691 | plog.Infof("aborting update cluster version because server is stopped") |
| 1692 | return |
| 1693 | default: |
| 1694 | plog.Errorf("error updating cluster version (%v)", err) |
| 1695 | } |
| 1696 | } |
| 1697 | |
| 1698 | func (s *EtcdServer) parseProposeCtxErr(err error, start time.Time) error { |
| 1699 | switch err { |
| 1700 | case context.Canceled: |
| 1701 | return ErrCanceled |
| 1702 | case context.DeadlineExceeded: |
| 1703 | s.leadTimeMu.RLock() |
| 1704 | curLeadElected := s.leadElectedTime |
| 1705 | s.leadTimeMu.RUnlock() |
| 1706 | prevLeadLost := curLeadElected.Add(-2 * time.Duration(s.Cfg.ElectionTicks) * time.Duration(s.Cfg.TickMs) * time.Millisecond) |
| 1707 | if start.After(prevLeadLost) && start.Before(curLeadElected) { |
| 1708 | return ErrTimeoutDueToLeaderFail |
| 1709 | } |
| 1710 | |
| 1711 | lead := types.ID(atomic.LoadUint64(&s.r.lead)) |
| 1712 | switch lead { |
| 1713 | case types.ID(raft.None): |
| 1714 | // TODO: return error to specify it happens because the cluster does not have leader now |
| 1715 | case s.ID(): |
| 1716 | if !isConnectedToQuorumSince(s.r.transport, start, s.ID(), s.cluster.Members()) { |
| 1717 | return ErrTimeoutDueToConnectionLost |
| 1718 | } |
| 1719 | default: |
| 1720 | if !isConnectedSince(s.r.transport, start, lead) { |
| 1721 | return ErrTimeoutDueToConnectionLost |
| 1722 | } |
| 1723 | } |
| 1724 | |
| 1725 | return ErrTimeout |
| 1726 | default: |
| 1727 | return err |
| 1728 | } |
| 1729 | } |
| 1730 | |
| 1731 | func (s *EtcdServer) KV() mvcc.ConsistentWatchableKV { return s.kv } |
| 1732 | func (s *EtcdServer) Backend() backend.Backend { |
| 1733 | s.bemu.Lock() |
| 1734 | defer s.bemu.Unlock() |
| 1735 | return s.be |
| 1736 | } |
| 1737 | |
| 1738 | func (s *EtcdServer) AuthStore() auth.AuthStore { return s.authStore } |
| 1739 | |
| 1740 | func (s *EtcdServer) restoreAlarms() error { |
| 1741 | s.applyV3 = s.newApplierV3() |
| 1742 | as, err := alarm.NewAlarmStore(s) |
| 1743 | if err != nil { |
| 1744 | return err |
| 1745 | } |
| 1746 | s.alarmStore = as |
| 1747 | if len(as.Get(pb.AlarmType_NOSPACE)) > 0 { |
| 1748 | s.applyV3 = newApplierV3Capped(s.applyV3) |
| 1749 | } |
| 1750 | if len(as.Get(pb.AlarmType_CORRUPT)) > 0 { |
| 1751 | s.applyV3 = newApplierV3Corrupt(s.applyV3) |
| 1752 | } |
| 1753 | return nil |
| 1754 | } |
| 1755 | |
| 1756 | func (s *EtcdServer) getAppliedIndex() uint64 { |
| 1757 | return atomic.LoadUint64(&s.appliedIndex) |
| 1758 | } |
| 1759 | |
| 1760 | func (s *EtcdServer) setAppliedIndex(v uint64) { |
| 1761 | atomic.StoreUint64(&s.appliedIndex, v) |
| 1762 | } |
| 1763 | |
| 1764 | func (s *EtcdServer) getCommittedIndex() uint64 { |
| 1765 | return atomic.LoadUint64(&s.committedIndex) |
| 1766 | } |
| 1767 | |
| 1768 | func (s *EtcdServer) setCommittedIndex(v uint64) { |
| 1769 | atomic.StoreUint64(&s.committedIndex, v) |
| 1770 | } |
| 1771 | |
| 1772 | // goAttach creates a goroutine on a given function and tracks it using |
| 1773 | // the etcdserver waitgroup. |
| 1774 | func (s *EtcdServer) goAttach(f func()) { |
| 1775 | s.wgMu.RLock() // this blocks with ongoing close(s.stopping) |
| 1776 | defer s.wgMu.RUnlock() |
| 1777 | select { |
| 1778 | case <-s.stopping: |
| 1779 | plog.Warning("server has stopped (skipping goAttach)") |
| 1780 | return |
| 1781 | default: |
| 1782 | } |
| 1783 | |
| 1784 | // now safe to add since waitgroup wait has not started yet |
| 1785 | s.wg.Add(1) |
| 1786 | go func() { |
| 1787 | defer s.wg.Done() |
| 1788 | f() |
| 1789 | }() |
| 1790 | } |
| 1791 | |
| 1792 | func (s *EtcdServer) Alarms() []*pb.AlarmMember { |
| 1793 | return s.alarmStore.Get(pb.AlarmType_NONE) |
| 1794 | } |