I want to backup data in mongo shard. How i can backup no downtime because they're in production. I can't do from mongodb official manual.
Back Up a Sharded Cluster with Database Dumps
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In Oracle developers can run sqls in nologging mode. Is it possible on Mongo DB or Mongo DB writes all operations into the oplog(operations log)?
A standalone server (not part of replica set or sharded cluster) does not employ the oplog.
I have a shard mongo cluster(shard node has no replica set), and some applications are using it, I want to real-time migrations to a replica set mongo cluster. Does anyone know how to do it? Thanks
I am using mongodump and mongorestore for taking the backup and recovering the MongoDB sharded cluster 3.2. ( 3 node cluster)
I have created a database called "testing" which has a collection named "collection1" and "collection2"
I have then enabled sharding on the "testing" database and sharded the collections "collection1" and "collection2".
I then tried taking the backup using
mongodump -d testing --out /backups/shard
Backup worked fine.
Next, I have dropped the database "testing"
Now I tried to restore it back using mongorestore.
mongorestore -d "testing" /backups/shard/testing/
Restored completed.
Although the database and its collections were restored. I see that sharding is not enabled in the restored database.
How to retain the sharded information of a particular database so that after the restore operation, the collection should be in the same sharded state.
Recently I purchased cluster account from MongoDB atlas. I had checked UI and MongoDB documentation but don't know create oplog db. And how to create a connection string for oplog?
Oplog collection is automatically created and maintained by mongoDB and is created under the local database. It is used internally by mongoDB to maintain the various nodes in sync in a replica set. Assume you have a three node replica set, one primary and two secondary. When a write operation happens in the primary, the event is logged in oplog collection and is used internally to replicate the same change in the secondary nodes.
So to use oplog you will need a MongoDB server configured as a replica set. Standalone instances of mongoDB do not have oplog as there is no need for replication in this case.
However, you may start a standalone instance as a replica set by using the command,
Start Mongo server in replica mode.
mongod --dbPath <path_to_data_file> --replSet rs0
Initiate the replica set.(Execute from mongo shell)
rs.initiate();
oplog is a mongodb replication feature. If you have choose replication cluster, you have it in the database named "local". See the collections in "local" database.
We have Sharded Mongo Cluster.
However some documents are sharded and others are unsharded.
We are planning to migrate these databases to new cluster.
Please update if there is any process or steps to migrate the data from one sharded cluster to the other.
We have two secondaries and 1 primary for each shard,MongoS,3 Config Servers,2 Arbitors.
I understood that copydb can not be used on the sharded collection.
Please suggest if there is any other way.