seaweedfs/unmaintained/change_replication/change_replication.go

85 lines
2.3 KiB
Go

package main
import (
"flag"
"fmt"
"os"
"path"
"strconv"
"github.com/chrislusf/seaweedfs/weed/glog"
"github.com/chrislusf/seaweedfs/weed/storage"
)
var (
fixVolumePath = flag.String("dir", "/tmp", "data directory to store files")
fixVolumeCollection = flag.String("collection", "", "the volume collection name")
fixVolumeId = flag.Int("volumeId", -1, "a volume id. The volume should already exist in the dir. The volume index file should not exist.")
targetReplica = flag.String("replication", "", "If just empty, only print out current replication setting.")
)
/*
This is to change replication factor in .dat file header. Need to shut down the volume servers
that has those volumes.
1. fix the .dat file in place
// just see the replication setting
go run change_replication.go -volumeId=9 -dir=/Users/chrislu/Downloads
Current Volume Replication: 000
// fix the replication setting
go run change_replication.go -volumeId=9 -dir=/Users/chrislu/Downloads -replication 001
Current Volume Replication: 000
Changing to: 001
Done.
2. copy the fixed .dat and related .idx files to some remote server
3. restart volume servers or start new volume servers.
*/
func main() {
flag.Parse()
fileName := strconv.Itoa(*fixVolumeId)
if *fixVolumeCollection != "" {
fileName = *fixVolumeCollection + "_" + fileName
}
datFile, err := os.OpenFile(path.Join(*fixVolumePath, fileName+".dat"), os.O_RDWR, 0644)
if err != nil {
glog.Fatalf("Open Volume Data File [ERROR]: %v", err)
}
defer datFile.Close()
header := make([]byte, storage.SuperBlockSize)
if _, e := datFile.Read(header); e != nil {
glog.Fatalf("cannot read volume %s super block: %v", fileName+".dat", e)
}
superBlock, err := storage.ParseSuperBlock(header)
if err != nil {
glog.Fatalf("cannot parse existing super block: %v", err)
}
fmt.Printf("Current Volume Replication: %s\n", superBlock.ReplicaPlacement)
if *targetReplica == "" {
return
}
replica, err := storage.NewReplicaPlacementFromString(*targetReplica)
if err != nil {
glog.Fatalf("cannot parse target replica %s: %v", *targetReplica, err)
}
fmt.Printf("Changing to: %s\n", replica)
superBlock.ReplicaPlacement = replica
header = superBlock.Bytes()
if n, e := datFile.WriteAt(header, 0); n == 0 || e != nil {
glog.Fatalf("cannot write super block: %v", e)
}
fmt.Println("Done.")
}