go.etcd.io/etcd@v3.3.27+incompatible/etcdctl/ctlv3/command/defrag_command.go (about)

     1  // Copyright 2016 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 command
    16  
    17  import (
    18  	"fmt"
    19  	"os"
    20  	"path/filepath"
    21  	"time"
    22  
    23  	"github.com/coreos/etcd/mvcc/backend"
    24  	"github.com/spf13/cobra"
    25  )
    26  
    27  var (
    28  	defragDataDir string
    29  )
    30  
    31  // NewDefragCommand returns the cobra command for "Defrag".
    32  func NewDefragCommand() *cobra.Command {
    33  	cmd := &cobra.Command{
    34  		Use:   "defrag",
    35  		Short: "Defragments the storage of the etcd members with given endpoints",
    36  		Run:   defragCommandFunc,
    37  	}
    38  	cmd.Flags().StringVar(&defragDataDir, "data-dir", "", "Optional. If present, defragments a data directory not in use by etcd.")
    39  	return cmd
    40  }
    41  
    42  func defragCommandFunc(cmd *cobra.Command, args []string) {
    43  	if len(defragDataDir) > 0 {
    44  		err := defragData(defragDataDir)
    45  		if err != nil {
    46  			fmt.Fprintf(os.Stderr, "Failed to defragment etcd data[%s] (%v)\n", defragDataDir, err)
    47  			os.Exit(ExitError)
    48  		}
    49  		return
    50  	}
    51  
    52  	failures := 0
    53  	c := mustClientFromCmd(cmd)
    54  	for _, ep := range c.Endpoints() {
    55  		ctx, cancel := commandCtx(cmd)
    56  		_, err := c.Defragment(ctx, ep)
    57  		cancel()
    58  		if err != nil {
    59  			fmt.Fprintf(os.Stderr, "Failed to defragment etcd member[%s] (%v)\n", ep, err)
    60  			failures++
    61  		} else {
    62  			fmt.Printf("Finished defragmenting etcd member[%s]\n", ep)
    63  		}
    64  	}
    65  
    66  	if failures != 0 {
    67  		os.Exit(ExitError)
    68  	}
    69  }
    70  
    71  func defragData(dataDir string) error {
    72  	var be backend.Backend
    73  
    74  	bch := make(chan struct{})
    75  	dbDir := filepath.Join(dataDir, "member", "snap", "db")
    76  	go func() {
    77  		defer close(bch)
    78  		be = backend.NewDefaultBackend(dbDir)
    79  
    80  	}()
    81  	select {
    82  	case <-bch:
    83  	case <-time.After(time.Second):
    84  		fmt.Fprintf(os.Stderr, "waiting for etcd to close and release its lock on %q. "+
    85  			"To defrag a running etcd instance, omit --data-dir.\n", dbDir)
    86  		<-bch
    87  	}
    88  	return be.Defrag()
    89  }