ClickHouse的备份和还原

 

首先要指定备份路劲。可以备份在本地，NFS挂载路径，甚至备份在S3上。
配置文件：

/etc/clickhouse-server/config.d/backup.xml

例如：

<clickhouse>
    <storage_configuration>
        <disks>
            <backups>
                <type>local</type>
				<path>/clickHouse/backups/</path>
            </backups>
        </disks>
    </storage_configuration>
    <backups>
        <allowed_disk>backups</allowed_disk>
    <allowed_path>/clickHouse/backups/</allowed_path>
    </backups>
</clickhouse>

其中/clickHouse/backups/是备份的路径，你可以指定任何路径。这里将备份路径命名为backups。
配置好xml之后，需要重启clickhouse实例

 

重启后检查：

clickhouse :) 
SELECT
    name,
    path,
    formatReadableSize(free_space) AS free,
    formatReadableSize(total_space) AS total,
    formatReadableSize(keep_free_space) AS reserved
FROM system.disks

┌─name────┬─path─────────────────┬─free──────┬─total─────┬─reserved─┐
│ backups │ /clickHouse/backups/ │ 67.54 GiB │ 31.67 GiB │ 0.00 B   │
│ default │ /var/lib/clickhouse/ │ 67.54 GiB │ 31.67 GiB │ 0.00 B   │
└─────────┴──────────────────────┴───────────┴───────────┴──────────┘

 

配置备份到S3：

<clickhouse>
  <storage_configuration>
    <disks>
      <s3>
        <type>s3</type>
        <endpoint>https://your_buckets_URL_address</endpoint>
        <access_key_id>X.........X</access_key_id>
        <secret_access_key>Y...........Y</secret_access_key>
      </s3>
    </disks>
  </storage_configuration>
  <backups>
    <allowed_disk>s3</allowed_disk>
    <allowed_path>/backups/</allowed_path>
  </backups>
</clickhouse>

 

配置后手动备份：

BACKUP TABLE|DATABASE table_name|database_name TO Disk('<backup_location>', 'backupName.zip');

RESTORE TABLE|DATABASE table_name|database_name FROM Disk('<backup_location>', 'backupName.zip'

 

备份参数
·async：异步地备份和还原。默认是同步的
·partitions：还原的分区列表。
·settings：比如compression_method、compression_level、密码、base_backup(增量备份使用到)、structure_only、storage_policy、s3_storage_class

查看备份信息

SELECT *
FROM system.backups
FORMAT Vertical

不过这个表是动态表，数据没有持久化。