113 lines
3.8 KiB
Go
113 lines
3.8 KiB
Go
// Copyright 2017 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 storage
|
|
|
|
import (
|
|
"fmt"
|
|
"os"
|
|
"time"
|
|
|
|
"go.etcd.io/etcd/server/v3/config"
|
|
"go.etcd.io/etcd/server/v3/etcdserver/api/snap"
|
|
"go.etcd.io/etcd/server/v3/storage/backend"
|
|
"go.etcd.io/etcd/server/v3/storage/schema"
|
|
"go.etcd.io/raft/v3/raftpb"
|
|
|
|
"go.uber.org/zap"
|
|
)
|
|
|
|
func newBackend(cfg config.ServerConfig, hooks backend.Hooks) backend.Backend {
|
|
bcfg := backend.DefaultBackendConfig(cfg.Logger)
|
|
bcfg.Path = cfg.BackendPath()
|
|
bcfg.UnsafeNoFsync = cfg.UnsafeNoFsync
|
|
if cfg.BackendBatchLimit != 0 {
|
|
bcfg.BatchLimit = cfg.BackendBatchLimit
|
|
if cfg.Logger != nil {
|
|
cfg.Logger.Info("setting backend batch limit", zap.Int("batch limit", cfg.BackendBatchLimit))
|
|
}
|
|
}
|
|
if cfg.BackendBatchInterval != 0 {
|
|
bcfg.BatchInterval = cfg.BackendBatchInterval
|
|
if cfg.Logger != nil {
|
|
cfg.Logger.Info("setting backend batch interval", zap.Duration("batch interval", cfg.BackendBatchInterval))
|
|
}
|
|
}
|
|
bcfg.BackendFreelistType = cfg.BackendFreelistType
|
|
bcfg.Logger = cfg.Logger
|
|
if cfg.QuotaBackendBytes > 0 && cfg.QuotaBackendBytes != DefaultQuotaBytes {
|
|
// permit 10% excess over quota for disarm
|
|
bcfg.MmapSize = uint64(cfg.QuotaBackendBytes + cfg.QuotaBackendBytes/10)
|
|
}
|
|
bcfg.Mlock = cfg.ExperimentalMemoryMlock
|
|
bcfg.Hooks = hooks
|
|
return backend.New(bcfg)
|
|
}
|
|
|
|
// OpenSnapshotBackend renames a snapshot db to the current etcd db and opens it.
|
|
func OpenSnapshotBackend(cfg config.ServerConfig, ss *snap.Snapshotter, snapshot raftpb.Snapshot, hooks *BackendHooks) (backend.Backend, error) {
|
|
snapPath, err := ss.DBFilePath(snapshot.Metadata.Index)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("failed to find database snapshot file (%v)", err)
|
|
}
|
|
if err := os.Rename(snapPath, cfg.BackendPath()); err != nil {
|
|
return nil, fmt.Errorf("failed to rename database snapshot file (%v)", err)
|
|
}
|
|
return OpenBackend(cfg, hooks), nil
|
|
}
|
|
|
|
// OpenBackend returns a backend using the current etcd db.
|
|
func OpenBackend(cfg config.ServerConfig, hooks backend.Hooks) backend.Backend {
|
|
fn := cfg.BackendPath()
|
|
|
|
now, beOpened := time.Now(), make(chan backend.Backend)
|
|
go func() {
|
|
beOpened <- newBackend(cfg, hooks)
|
|
}()
|
|
|
|
defer func() {
|
|
cfg.Logger.Info("opened backend db", zap.String("path", fn), zap.Duration("took", time.Since(now)))
|
|
}()
|
|
|
|
select {
|
|
case be := <-beOpened:
|
|
return be
|
|
|
|
case <-time.After(10 * time.Second):
|
|
cfg.Logger.Info(
|
|
"db file is flocked by another process, or taking too long",
|
|
zap.String("path", fn),
|
|
zap.Duration("took", time.Since(now)),
|
|
)
|
|
}
|
|
|
|
return <-beOpened
|
|
}
|
|
|
|
// RecoverSnapshotBackend recovers the DB from a snapshot in case etcd crashes
|
|
// before updating the backend db after persisting raft snapshot to disk,
|
|
// violating the invariant snapshot.Metadata.Index < db.consistentIndex. In this
|
|
// case, replace the db with the snapshot db sent by the leader.
|
|
func RecoverSnapshotBackend(cfg config.ServerConfig, oldbe backend.Backend, snapshot raftpb.Snapshot, beExist bool, hooks *BackendHooks) (backend.Backend, error) {
|
|
consistentIndex := uint64(0)
|
|
if beExist {
|
|
consistentIndex, _ = schema.ReadConsistentIndex(oldbe.ReadTx())
|
|
}
|
|
if snapshot.Metadata.Index <= consistentIndex {
|
|
return oldbe, nil
|
|
}
|
|
oldbe.Close()
|
|
return OpenSnapshotBackend(cfg, snap.New(cfg.Logger, cfg.SnapDir()), snapshot, hooks)
|
|
}
|