Transfer MongoDB to another server? - mongodb

If I populate a MongoDB instance on my local machine, can I wholesale transfer that database to a server and have it work without too much effort?
The reason I ask is that my server is currently an Amazon EC2 Micro instance and I need to put LOTS of data into a MongoDB and don't think I can spare the transactions and bandwidth on the EC2 instance.

There is copy database command which I guess should be good fit for your need.
Alternatively, you can just stop MongoDb, copy the database files to another server and run an instance of MongoDb there.

Related

Mongodb clone to another cluster

The idea here is, I have mongo cluster deployed in managed cloud service atlas. I have enabled Continuous Backup.
Now what I want to do is :
1) I want to use existing backup.
2) Using this existing backup I want to create similar cluster
(having same data form backup)
3) Automate this process so that every day my new cluster gets upto date from original cluster.
Note: The idea here for cloning cluster is, The original cluster is production data. I want to create a db which has similar data on which I can plug and play using any analytic tools and perform diffrent operations without affecting production data and load.
So far what I have found is to use mongorestore and mongodump.But here mongodump is putting load on production db even though my backup is enabled. I want to use same backup to clone this to another db cluster.
Deployed on Atlas, your server must have replica set.
Here are 2 solutions :
You need only reading data : connect your tools to a secondary server (ideally dedicated with priority 0 for becoming primary)
You need to read/write data : on the same server than above, play your mongodump command with --oplog option. By this way, you're dumping your data from a read-only server, preventing slowing performances of your main servers.
In this last case, what you need will find its solution in backup strategies, take a look at the doc to know more.
There's an offering for this purpose in ATLAS called analytic node.Link.
Analytic node is read replica of your database. Plus it will not interfere with your production traffic which makes it safer.
Also, you can connect BI connectors to this node and create your analytic platform.
We used redash.

MongoDB data directory on remote server

I was wondering if there is any way to have separate servers for engine and storage of MongoDB? I am interested in running the MongoDB engine on a local Ubuntu machine but store the data remotely on another server, like having a remote address for MongoDB data directory.
Whether it's possible or not, it wouldn't be advisable. MongoDB really benefits from fast disk i/o, but if your data is stored on a remote server then the network latency would make the disk i/o very slow.

Where does MongoDB Atlas fit in my nodejs app?

I have an express app using MongoDB up and running locally. I am looking at options to deploy and wasn't clear on how MongoDB atlas fit in. I planning on just deploying the express app and database to an ec2 instance. Is that alright? Or do I need a separate instance for mongo to run on? MongoDB Atlas offers M2, M5, M10 etc. as options for nodes. I am very new at backend and want to know if those would be separate from my EC2 instance or if those would be my EC2 instance running my express app for clients to connect to as well.
Mongo Atlas is a standalone hosted MongoDB instance. It's a separate server, or typically a cluster of several servers, that only runs MongoDB. You'd run your Express app on an EC2 instance and have it talk over the network to the Mongo Atlas instance on another server.
The advantage is that you don't have to worry about installing or handholding Mongo, about configuring a redundant Mongo cluster, about upgrades or backups. Generally, separating the database server from the application server also means easier longterm maintenance of both. If your Express server doesn't store any data itself, then it is entirely disposable in case of emergencies, while you can be assured* that the critical data stored in your database is well cared for.
* As far as your contract with Atlas stipulates that the data is being cared for…

Replicate data from one RDS server to another

Can we replicate data from one RDS server to another? Or can we set master slave relationship between two RDS servers?
Should we replicate data from non RDS instance to RDS instance?
RDS can replicate from external mysql and also be a master of an external slave. It depends on your usecase if you "should" do it.
http://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/MySQL.Procedural.Importing.External.Repl.html
While i guess you could setup replication between two RDS instances yourself I don't see why you should since starting a RDS read replica is just a few clicks in AWS console or an api call.
It can be possible to replicate data from RDS to RDS. It is also possible to replicate data from RDS to some other MySQL server.
Steps:
You can go creating your ec2 server and install MySQL.
Change configuration to replicate data.
That will require additional work to manage ec2 instance in case if your data is increasing and crossing the server limits
Then you have to do all the manual work again to replicate data as we can't increase storage in ec2 server.
RDS provides an easy mechanism to create Read replica via a few clicks. (Note: replica is quite a costlier option.)
But going with that you will save manual work one person salary who will be managing the database and doing these setups regularly.
If you are using postgresql database on RDS then you can use bucardo for asynchronous replication. You need to create a EC2 or use can use local system also but it will not be fast enough.
Use the following tutorial if you want to use bucardo.
https://www.installvirtual.com/how-to-install-bucardo-for-postgres-replication/
I think you can using snapshot to clone another rds database

Local MongoDB instance with index in remote server

One of our clients have a server running a MongoDB instance and we have to build an analytical application using the data stored in their MongoDB database which changes frequently.
Clients requirements are:
That we do not connect to their MongoDB instance directly or run another instance of MongoDB on their server but just somehow run our own MongoDB instance on our machine in our office using their MongoDB database directory with read only access remotely.
We've suggested deploying a REST application, getting a copy of their database dump but they did not want that. They just want us to run our own MongoDB intance which is hooked up with the MongoDB instance directory. Is this even possible ?
I've been searching for a solution for the past two days and we have to submit a solution by Monday. I really need some help.
I think this is normal request because analytical queries could cause too much load on the production server. It is pretty normal to separate production and analytical databases.
The easiest option is to use MongoDB replication. Set up MongoDB replica set with production database instance as primary and analytical database instance as secondary, also configure the analytical instance to never become primary.
If it is not possible to use replication - for example client doesn't want this, the servers could not connect directly to each other... - there is another option. You can read oplog from remote database and apply operations to your database instance. This is exactly the low level mechanism how replica set works, but you can do it manually too. For example MMS (Mongo Monitoring Sevice) Backup uses reading oplog for online backups of MongoDB.
Update: mongooplog could be the right tool for real-time application of replication oplog pulled from remote server on local server.
I don't think that running two databases that points to the same database files is possible or even recommended.
You could use mongorestore to restore from their data files directly, but this will only work if their mongod instance is not running (because mongorestore will need to lock the directory).
Another solution will be to do file system snapshots and then restore to your local database.
The downside to this backup/restore solutions is that your data will not be synced all the time.
Probably the best solution will be to use replica sets with hidden members.
You can create a replica set with just two members:
Primary - this will be the client server.
Secondary - hidden, with votes and priority set to 0. This will be your local instance.
Their server will always be primary (because hidden members cannot become primaries). Clients cannot see hidden members so for all intents and purposes your server will be read only.
Another upside to this is that the MongoDB replication will do all the "heavy" work of syncing the data between servers and your instance will always have the latest data.