MongoDB数据备份和导入数据

MongoDB进行热备份

Mongodb自带了mongodump和mongorestore这两个工具来实现对数据的备份和恢复。

mongodump能够在Mongodb运行时进行备份，它的工作原理是对运行的Mongodb做查询，然后将所有查到的文档写入磁盘。但是存在的问题时使用mongodump产生的备份不一定是数据库的实时快照，如果我们在备份时对数据库进行了写入操作，则备份出来的文件可能不完全和Mongodb实时数据相等。

mongodump 进行热备份

mongodump工具使用说明：

$ mongodump --help
Export MongoDB data to BSON files.
 
options:
  --help                   produce help message
  -v [ --verbose ]         be more verbose (include multiple times for more 
                           verbosity e.g. -vvvvv)
  --version                print the program's version and exit
  -h [ --host ] arg        mongo host to connect to ( <set name>/s1,s2 for 
                           sets)
  --port arg               server port. Can also use --host hostname:port
  --ipv6                   enable IPv6 support (disabled by default)
  -u [ --username ] arg    username
  -p [ --password ] arg    password
  --dbpath arg             directly access mongod database files in the given 
                           path, instead of connecting to a mongod  server - 
                           needs to lock the data directory, so cannot be used 
                           if a mongod is currently accessing the same path
  --directoryperdb         if dbpath specified, each db is in a separate 
                           directory
  --journal                enable journaling
  -d [ --db ] arg          database to use
  -c [ --collection ] arg  collection to use (some commands)
  -o [ --out ] arg (=dump) output directory or "-" for stdout
  -q [ --query ] arg       json query
  --oplog                  Use oplog for point-in-time snapshotting
  --repair                 try to recover a crashed database
  --forceTableScan         force a table scan (do not use $snapshot)

参数说明：

-h:指明数据库宿主机的IP
-u:指明数据库的用户名
-p:指明数据库的密码
-d:指明数据库的名字
-c:指明collection的名字(不指定，则所有的集合)
-o:指明到要导出的文件名
-q:指明导出数据的过滤条件
-u:用户名
-p:密码

例如：

$ mongodump -h 127.0.0.1:27021 -u 用户名 -p 密码 -d 数据库名 -o 备份文件夹名或者路径

实例：

$ mongodump -h 127.0.0.1:27021 -u xx -p xx -d kk -o bak
2018-12-20T09:58:51.473+0800    writing kk.xxxx to 
2018-12-20T09:58:51.473+0800    writing kk.x2 to 
2018-12-20T09:58:51.473+0800    writing kk.x3 to 
2018-12-20T09:58:51.548+0800    done dumping kk.xxxx (1 document)
2018-12-20T09:58:51.550+0800    done dumping kk.x2 (29 documents)
2018-12-20T09:58:51.550+0800    done dumping kk.x3 (34 documents)

mongorestore 进行恢复数据

mongorestore 使用说明。

mongorestore --help
usage: ./bin/mongorestore [options] [directory or filename to restore from]
options:
  --help                  produce help message
  -v [ --verbose ]        be more verbose (include multiple times for more 
                          verbosity e.g. -vvvvv)
  --version               print the program's version and exit
  -h [ --host ] arg       mongo host to connect to ( <set name>/s1,s2 for sets)
  --port arg              server port. Can also use --host hostname:port
  --ipv6                  enable IPv6 support (disabled by default)
  -u [ --username ] arg   username
  -p [ --password ] arg   password
  --dbpath arg            directly access mongod database files in the given 
                          path, instead of connecting to a mongod  server - 
                          needs to lock the data directory, so cannot be used 
                          if a mongod is currently accessing the same path
  --directoryperdb        if dbpath specified, each db is in a separate 
                          directory
  --journal               enable journaling
  -d [ --db ] arg         database to use
  -c [ --collection ] arg collection to use (some commands)
  --objcheck              validate object before inserting
  --filter arg            filter to apply before inserting
  --drop                  drop each collection before import
  --oplogReplay           replay oplog for point-in-time restore
  --keepIndexVersion      don't upgrade indexes to newest version