etcd数据备份与恢复
一 wal介绍
wal是write ahead log的缩写，顾名思义，也就是在执行真正的写操作之前先写一个日志，预写日志。
wal:存放预写式日志，最大的作用是记录了整个数据变化的全部历程。在etcd中,所有数据的修改在提交前，都要先写入wal中。
二 etcd 数据备份
2.1 查看etcd版本信息
root@k8s-etcd-01:~# etcdctl version
etcdctl version: 3.5.0
API version: 3.5
2.2 查看etcd v3版本备份帮助
点击查看代码
root@k8s-etcd-01:~# etcdctl snapshot save --help
NAME:
snapshot save - Stores an etcd node backend snapshot to a given file
USAGE:
etcdctl snapshot save <filename> [flags]
OPTIONS:
-h, --help[=false] help for save
GLOBAL OPTIONS:
--cacert="" verify certificates of TLS-enabled secure servers using this CA bundle
--cert="" identify secure client using this TLS certificate file
--command-timeout=5s timeout for short running command (excluding dial timeout)
--debug[=false] enable client-side debug logging
--dial-timeout=2s dial timeout for client connections
-d, --discovery-srv="" domain name to query for SRV records describing cluster endpoints
--discovery-srv-name="" service name to query when using DNS discovery
--endpoints=[127.0.0.1:2379] gRPC endpoints
--hex[=false] print byte strings as hex encoded strings
--insecure-discovery[=true] accept insecure SRV records describing cluster endpoints
--insecure-skip-tls-verify[=false] skip server certificate verification (CAUTION: this option should be enabled only for testing purposes)
--insecure-transport[=true] disable transport security for client connections
--keepalive-time=2s keepalive time for client connections
--keepalive-timeout=6s keepalive timeout for client connections
--key="" identify secure client using this TLS key file
--password="" password for authentication (if this option is used, --user option shouldn't include password)
--user="" username[:password] for authentication (prompt if password is not supplied)
-w, --write-out="simple" set the output format (fields, json, protobuf, simple, table)
2.3 etcd v3版本数据手动备份
root@k8s-etcd-01:~# etcdctl snapshot save snapshot.db
{"level":"info","ts":1636787145.641446,"caller":"snapshot/v3_snapshot.go:68","msg":"created temporary db file","path":"snapshot.db.part"}
{"level":"info","ts":1636787145.6563053,"logger":"client","caller":"v3/maintenance.go:211","msg":"opened snapshot stream; downloading"}
{"level":"info","ts":1636787145.6563435,"caller":"snapshot/v3_snapshot.go:76","msg":"fetching snapshot","endpoint":"127.0.0.1:2379"}
{"level":"info","ts":1636787145.6818144,"logger":"client","caller":"v3/maintenance.go:219","msg":"completed snapshot read; closing"}
{"level":"info","ts":1636787145.7401688,"caller":"snapshot/v3_snapshot.go:91","msg":"fetched snapshot","endpoint":"127.0.0.1:2379","size":"3.9 MB","took":"now"}
{"level":"info","ts":1636787145.7402475,"caller":"snapshot/v3_snapshot.go:100","msg":"saved","path":"snapshot.db"}
Snapshot saved at snapshot.db
2.3 etcd v3版本数据自动备份
#!/bin/bash
source /etc/profile
DATE=`date +%Y-%m-%d_%H_%M_%S`
ETCDCTL_API=3 /usr/bin/etcdctl snaphost save /data/etcd-backup-dri/etcd-snapshot-${DATE}.db
三 etcd v3版本数据恢复
3.1 etcd v3版本数据恢复帮助
点击查看代码
root@k8s-etcd-01:~# ETCDCTL_API=3 etcdctl snapshot restore --help
NAME:
snapshot restore - Restores an etcd member snapshot to an etcd directory
USAGE:
etcdctl snapshot restore <filename> [options] [flags]
DESCRIPTION:
Moved to `etcdctl snapshot restore ...`
OPTIONS:
--data-dir="" Path to the data directory
-h, --help[=false] help for restore
--initial-advertise-peer-urls="http://localhost:2380" List of this member's peer URLs to advertise to the rest of the cluster
--initial-cluster="default=http://localhost:2380" Initial cluster configuration for restore bootstrap
--initial-cluster-token="etcd-cluster" Initial cluster token for the etcd cluster during restore bootstrap
--name="default" Human-readable name for this member
--skip-hash-check[=false] Ignore snapshot integrity hash value (required if copied from data directory)
--wal-dir="" Path to the WAL directory (use --data-dir if none given)
GLOBAL OPTIONS:
--cacert="" verify certificates of TLS-enabled secure servers using this CA bundle
--cert="" identify secure client using this TLS certificate file
--command-timeout=5s timeout for short running command (excluding dial timeout)
--debug[=false] enable client-side debug logging
--dial-timeout=2s dial timeout for client connections
-d, --discovery-srv="" domain name to query for SRV records describing cluster endpoints
--discovery-srv-name="" service name to query when using DNS discovery
--endpoints=[127.0.0.1:2379] gRPC endpoints
--hex[=false] print byte strings as hex encoded strings
--insecure-discovery[=true] accept insecure SRV records describing cluster endpoints
--insecure-skip-tls-verify[=false] skip server certificate verification (CAUTION: this option should be enabled only for testing purposes)
--insecure-transport[=true] disable transport security for client connections
--keepalive-time=2s keepalive time for client connections
--keepalive-timeout=6s keepalive timeout for client connections
--key="" identify secure client using this TLS key file
--password="" password for authentication (if this option is used, --user option shouldn't include password)
--user="" username[:password] for authentication (prompt if password is not supplied)
-w, --write-out="simple" set the output format (fields, json, protobuf, simple, table)
3.2 停止etcd服务
root@k8s-etcd-01:~# systemctl stop etcd
3.3 删除etcd存储数据目录
root@k8s-etcd-01:~# ls -l /var/lib/etcd/
total 4
drwx------ 4 root root 4096 Nov 13 14:42 member
root@k8s-etcd-01:~# rm -rf /var/lib/etcd3.4 etcd v3版本数据恢复
root@k8s-etcd-01:~# ETCDCTL_API=3 etcdctl snapshot restore snapshot.db --data-dir=/var/lib/etcd
Deprecated: Use `etcdutl snapshot restore` instead.
2021-11-13T15:19:07+08:00 info snapshot/v3_snapshot.go:251 restoring snapshot {"path": "snapshot.db", "wal-dir": "/var/lib/etcd/member/wal", "data-dir": "/var/lib/etcd", "snap-dir": "/var/lib/etcd/member/snap", "stack": "go.etcd.io/etcd/etcdutl/v3/snapshot.(*v3Manager).Restore\n\t/tmp/etcd-release-3.5.0/etcd/release/etcd/etcdutl/snapshot/v3_snapshot.go:257\ngo.etcd.io/etcd/etcdutl/v3/etcdutl.SnapshotRestoreCommandFunc\n\t/tmp/etcd-release-3.5.0/etcd/release/etcd/etcdutl/etcdutl/snapshot_command.go:147\ngo.etcd.io/etcd/etcdctl/v3/ctlv3/command.snapshotRestoreCommandFunc\n\t/tmp/etcd-release-3.5.0/etcd/release/etcd/etcdctl/ctlv3/command/snapshot_command.go:128\ngithub.com/spf13/cobra.(*Command).execute\n\t/home/remote/sbatsche/.gvm/pkgsets/go1.16.3/global/pkg/mod/github.com/spf13/cobra@v1.1.3/command.go:856\ngithub.com/spf13/cobra.(*Command).ExecuteC\n\t/home/remote/sbatsche/.gvm/pkgsets/go1.16.3/global/pkg/mod/github.com/spf13/cobra@v1.1.3/command.go:960\ngithub.com/spf13/cobra.(*Command).Execute\n\t/home/remote/sbatsche/.gvm/pkgsets/go1.16.3/global/pkg/mod/github.com/spf13/cobra@v1.1.3/command.go:897\ngo.etcd.io/etcd/etcdctl/v3/ctlv3.Start\n\t/tmp/etcd-release-3.5.0/etcd/release/etcd/etcdctl/ctlv3/ctl.go:107\ngo.etcd.io/etcd/etcdctl/v3/ctlv3.MustStart\n\t/tmp/etcd-release-3.5.0/etcd/release/etcd/etcdctl/ctlv3/ctl.go:111\nmain.main\n\t/tmp/etcd-release-3.5.0/etcd/release/etcd/etcdctl/main.go:59\nruntime.main\n\t/home/remote/sbatsche/.gvm/gos/go1.16.3/src/runtime/proc.go:225"}
2021-11-13T15:19:07+08:00 info membership/store.go:119 Trimming membership information from the backend...
2021-11-13T15:19:07+08:00 info membership/cluster.go:393 added member {"cluster-id": "cdf818194e3a8c32", "local-member-id": "0", "added-peer-id": "8e9e05c52164694d", "added-peer-peer-urls": ["http://localhost:2380"]}
2021-11-13T15:19:07+08:00 info snapshot/v3_snapshot.go:272 restored snapshot {"path": "snapshot.db", "wal-dir": "/var/lib/etcd/member/wal", "data-dir": "/var/lib/etcd", "snap-dir": "/var/lib/etcd/member/snap"}
