The local database mainly stores metadata such as configuration information of the replica set and oplog, and the admin database mainly stores information such as users and roles. In order to prevent data disorder and authentication failures, TencentDB for MongoDB prohibits importing local and admin databases into an instance.

In CVM, you can use the MongoDB shell client to connect to TencentDB for MongoDB for data import and export. Please be sure to use the latest MongoDB client suite. For detailed directions, please see Connection Sample.

Export and Import Commands

MongoDB provides two sets of official tools for data import and export:

• mongodump and mongorestore
• mongoexport and mongoimport

mongodump and mongorestore

mongodump and mongorestore are generally used to export and import an entire database, as they manipulate data in BSON format, which is more efficient when a large number of dump and restore operations are performed.

• The export command for mongodump is as follows:

  mongodump --host 10.66.187.127:27017 -u mongouser -p thepasswordA1 --authenticationDatabase=admin --db=testdb -o /data/dump_testdb

  
• The import command for mongorestore is as follows:

  mongorestore --host 10.66.187.127:27017 -u mongouser -p thepasswordA1 --authenticationDatabase=admin --dir=/data/dump_testdb

  

mongoexport and mongoimport

mongoexport and mongoimport are generally used to export and import a single set, as they manipulate data in JSON format, which features a higher readability.

• The export command for mongoexport is as follows:

  mongoexport --host 10.66.187.127:27017 -u mongouser -p thepasswordA1 --authenticationDatabase=admin --db=testdb --collection=testcollection -o /data/export_testdb_testcollection.json

  In addition, you can also include the -f parameter to specify a desired field or the -q parameter to specify a query condition so as to restrict the data to be exported.
• The import command for mongoimport is as follows:

  mongoimport --host 10.66.187.127:27017 -u mongouser -p thepasswordA1 --authenticationDatabase=admin --db=testdb --collection=testcollection2 --file=/data/export_testdb_testcollection.json

Parameter Description for Multiple Authentication Methods

As described in the Connection Sample, TencentDB for MongoDB provides two usernames rwuser and mongouser by default to support the MONGODB-CR and SCRAM-SHA-1 authentication methods, respectively.

• For mongouser and all new users created in the console, simply follow the above samples to use the import and export tools.
• For rwuser, the parameter --authenticationMechanism=MONGODB-CR should be included in each command.

mongodump sample:

mongodump --host 10.66.187.127:27017 -u rwuser -p thepasswordA1 --authenticationDatabase=admin --authenticationMechanism=MONGODB-CR --db=testdb -o /data/dump_testdb