Migrate from MongoDB with mongodump and mongorestore

TeselaDB speaks the MongoDB protocol, so the migration uses mongodump and mongorestore, the MongoDB database tools. Your application does not change: only its connection string.

Before you start

• A running TeselaDB cluster (Your first cluster) and its CA, pki/ca.pem.
• A user with the restore role on TeselaDB, or root for the migration.
• The MongoDB Database Tools installed on a machine that can reach both.

1. Export from MongoDB

mongodump --uri "mongodb://user:<password>@mongo-01:27017/shop" --gzip --archive=shop.gz

If you do not want to stop writes during the copy, export the whole replica set with --oplog: the archive includes the operations that happen while the export runs.

mongodump --uri "mongodb://user:<password>@mongo-01:27017/?replicaSet=rs0" --oplog --gzip --archive=all.gz

2. Import into TeselaDB

mongorestore --uri "mongodb://root:<password>@node-01:27017/?tls=true&tlsCAFile=./ca.pem" \
  --gzip --archive=shop.gz

With an archive made with --oplog, add --oplogReplay to apply those operations at the end. mongorestore also creates the indexes, and TeselaDB splits each collection into ranges as the documents arrive.

3. Check the data

db.orders.countDocuments();
db.orders.getIndexes();

Compare the counts and indexes with MongoDB's before moving the traffic.

4. Change the connection string

mongodb://shop-api:<password>@node-01:27017,node-02:27017,node-03:27017/shop?tls=true&tlsCAFile=./ca.pem

Create a user for the application with only the roles it needs (Users and roles) and check Differences with MongoDB in case your application depends on a behaviour that changes, such as the order of a find without sort.