We are creating Meteor-based Mongo database manager and we need the ability to "unmount" (remove from system) all collections when we switch databases.
Example:
I'm managing database called dbA. We have all collections for that database created using Mongo.Collection() on server and on client side.
I want to switch database to dbB. I need to unmount all Collections of dbA and mount those of dbB. Reason: dbB could have a collection of the same name as dbA (and usually does)
Is there a way to do this?
Thanks!
You may be able to accomplish this by publishing the necessary data from the new database.
Here's a discussion from a similar question on the Meteor Forums (note the proposed solution at the end):
https://forums.meteor.com/t/switch-database-while-meteor-is-running/4361/5
hi i think you can do with
db.copyDatabase()
run the shell command in the backend from meteor server and execute the copy database command. and after the database is copied you can remove the previous collection.
more detail about copyDatabase() is here
https://docs.mongodb.org/manual/reference/method/db.copyDatabase/
Related
Currently I am trying to clone a cosmos db collection from one database to another database within the cosmos db. The API of the cosmos db is set to Mongo API.
I already tried to use Azure Data factory, but it looks like that there is no support for the Mongo API so far.
Has anyone an idea how to do this respective to efficiency, automation and performance?
Any ideas are appreciated.
You can use data Migration tool suggested by Microsoft to do the same.
There is no way to take a backup and import cosmosdb.
EDIT:
With the new Cosmic Clone tool, you can take a clone/backup with data/stored procedures/triggers/udf, etc. Read my blog on the same.
I already tried to use Azure Data factory, but it looks like that
there is no support for the Mongo API so far.
Actually, Cosmos DB Mongo API and SQL API are all belong to Azure Cosmos DB service.So , you still can create cosmos db linked service and dataset in the azure data factory for your database.
Then you could create copy activity to import data from one collection to another collection.
If you want to make it as an automation task, I suggest using following 2 ways to run the copy activity.
1.Azure Time Trigger Function.
2.Web job which is run in the background of Azure Web App.
Hope it helps you.Any concern, please feel free to let me know.
I used mongodump and mongorestore to copy my database (with mongodb version 4.0.9 installed). From the windows command line I ran the following commands from my mongodb bin directory (c:\Program Files\MongoDB\Server\4.0\bin in my case).
This will copy all the collections, including indexes, in the DB to the specified /out directory as .json files.
mongodump.exe /uri:URI /out:A_DIRECTORY_TO_DUMP_TO
I then ran the following command to take everything in the /out directory and write it to the target DB:
mongorestore.exe /uri:URI /dir:DIRECTORY_TO_RESTORE_FROM
NOTE: Before importing I also had to increase the throughput for the collection, otherwise I ran into rate limiting errors. If you've set throughput at the database level this may need to be changed.
I am new in Meteorjs and i am using mongo db which comes with the meteor package.
I have made one small meteor application using mongodb and now i want to take backup of the mongo db database. I have seen many web sites and still i am not able to backup my data base. Everyone explained the same thing that in mongo db folder use mongodump and mongostore but when i use mongodump and mongostore on my terminal then it displays something like 'mongodump' is not an internal or external source command. Can u please help me in finding out the solution.
I have found that the easiest way to backup your database (or move it between meteor installations for that matter) is to simple copy the files in .meteor\local\db
Then you don't have to worry about all that mongodb dump stuff. Simple.
I've installed new MongoDB server and now I want to import data from the old one. My MongoDB stores monitoring data and it's a bit problematic to export the data from old database (it's over 10Gb), so I though it might be possible to import directly from DB, but haven't found how to do that with mongoimport.
The export/import would be the fastest option.
But if you really want to bypass it you can use the new server as a replica of the old one, and wait for full replication.
It takes longer but it's an easy way to set up a full copy without impact on the first one.
Follow this:
http://docs.mongodb.org/manual/tutorial/convert-standalone-to-replica-set/
And then, once it's done, change configuration again.
It's easiest than it seems, but I recommend you to do a dry run with a sample database before doing it...
Note that another benefit is that the new replica will be probably smaller in size than the initial database, because MongoDb is not very good at freeing space of deleted members
mongoimport/mongoexport is per collection operating, so it's not proper for this kind of operation.
Instead to use mongodump/mongorestore.
If the old MongoDB instance can be shutdown to do this task, you can shut down it then copy all data files to the new server as its own data. And run the new instance.
Also db.cloneDatabase() can handle it to copy data directly from old instance to new one. It should be slower against copying data files directly.
You can use mongodump and pipe directly to the new database with mongorestore like:
mongodump --archive --db=test | mongorestore --archive --nsFrom='test.*' --nsTo='examples.*'
add --host --port and --username to mongorestore to connect to the remote db.
db.cloneDatabase() has been deprecated for a while.
You can use the copydb command discribed here.
Copies a database from a remote host to the current host or copies a database to another database within the current host.
copydb runs on the destination mongod instance, i.e. the host receiving the copied data.
It's possible to connect meteor manually to 2 or more databases in order to have a normal mongo that saves to the disk and a memory one like redis?
I'm asking because mongo has already full support from meteor and using it would be a lot easier than redis or other database
Right now, a Meteor server can only connect to one (and exactly one) Mongo database.
Redis support is on the roadmap, as is SQL support. Once Meteor supports multiple databases, you will have more options for how to set up your databases as well as dividing up your data between them. The only way to do what you are saying right now is to have your Meteor client connect to two different Meteor servers, and have one of them clear/dump the database regularly.
Source: discussions at Meteor's offices.
I'm a beginner with MongoDB and I've some questions:
When I'm connected to Mongo, and i execute show dbs I see 2 databases: admin and local. What's their role? Then if I execute an insert command like db.foo.insert({"value":"mongo"}), the test database appears. Why? How can i specify a custom name for a database?
With show dbs I get the databases (somehow like show databases in sql), how can I then list the collections inside a database (I would use show tables in sql)?
When executing a command, the MongoDB tutorial always uses the db object. Is it the main object (a sort of "connection" object) that has to used for executing commands or it's something else?
Thanks!
admin and local contain various settings local to the server, like users who are authenticated to connect. Under beginner usage, you shouldn't need to worry about them at all. By default you connect to a database named test. To connect to a new database, just use databasename from the mongo command line, or mongo databasename from your OS shell.
use [database_name] and then show collections
The db object is your root handle to the currently-selected database on the mongo commmand line. The command line is really just a Javascript command line, and there are various mongodb-specific objects and functions exposed that let you do stuff. Try help() for a full listing.