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Creating a MongoDB data service#

This tutorial creates an Ametnes-managed MongoDB database — a private document service reached through an Ametnes network access endpoint.

Ametnes offers the MongoDB community server in two release families:

  • service/mongodb:8.0 — MongoDB 8.0 LTS
  • service/mongodb:9.0 — MongoDB 9.0

Every architecture tier runs a three-member replica set. There is no single-node tier: Starter is already a highly-available three-node deployment, with one primary and two secondaries.

Prerequisites#

  1. A service location (see Service Location).

Networking is automatic by default

Creating a network access resource is optional. If you do not create one, Ametnes manages network access for the location and the service attaches automatically. Create your own only if you want to control exposure (see Network Access Resources).

Connections#

The service returns three member connections:

Connection Default port Role
mongodb 27017 Primary member
secondary 27018 Secondary member
tertiary 27019 Secondary member

The control plane may allocate different external ports when the defaults are already in use on the endpoint. Always use the host and port returned in the service's connections array rather than assuming the defaults.

All three hosts advertise the same replica set name, rs0. Clients should use all three connections and let the MongoDB driver discover the current primary; the primary role can move between members.

Create the MongoDB service#

  1. Navigate to Services and click New Service.
  2. Enter Name (for example MongoDBService).
  3. Select Kind: MongoDB 8.0 Service or MongoDB 9.0 Service.
  4. Select the Location: your data service location. Leave Network unset to let Ametnes manage it.
  5. Select Setup Architecture:
    • Starter for evaluation and small workloads (3 nodes, 1 CPU / 2Gi per node, 10Gi per node).
    • Small and above for larger production workloads.
  6. Set Admin User (default root) and Admin Password. A password is generated when omitted.
  7. Click Create Service and wait for status READY.
service.tf
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resource "ametnes_service" "mongodb" {
  name     = "MongoDBService"
  project  = ametnes_project.project.id
  location = data.ametnes_location.location.id
  kind     = "service/mongodb:8.0"
  capacity {
    storage = 10
  }
  config = {
    "architecture"   = "Starter"
    "admin.user"     = "root"
    "admin.password" = "change-me"
  }
}

output "connections" {
  value = ametnes_service.mongodb.connections
}

Change kind to service/mongodb:9.0 to provision MongoDB 9.0. The architecture controls CPU, memory, replica count and per-node storage; every architecture remains a three-member replica set.

Connect#

Use the three MongoDB member connections returned by the service. The connection string uses the replica set name, rs0, and authenticates against the admin database:

mongodb://root:<password>@<mongodb-host>:<mongodb-port>,<secondary-host>:<secondary-port>,<tertiary-host>:<tertiary-port>/?replicaSet=rs0&authSource=admin&tls=true&retryWrites=true&w=majority

With mongosh:

mongosh "mongodb://root:<password>@<host-1>:<port-1>,<host-2>:<port-2>,<host-3>:<port-3>/?replicaSet=rs0&authSource=admin&tls=true"

The admin user defaults to root. Use the password from the service's secret, or the password you supplied at creation time.

Architectures#

Every architecture is a three-node replica set. Requests are half of the limits, and storage is per node, so the total raw storage is three times the listed per-node size.

Architecture Nodes CPU / memory per node Storage per node ACU
Starter 3 1 CPU / 2Gi 10Gi 6
Small 3 2 CPU / 4Gi 25Gi 12
Basic 3 2 CPU / 4Gi 50Gi 12
Medium 3 4 CPU / 8Gi 100Gi 24
Large 3 8 CPU / 16Gi 250Gi 48
XLarge 3 16 CPU / 32Gi 500Gi 96
2XLarge 3 24 CPU / 64Gi 1000Gi 192
3XLarge 3 32 CPU / 96Gi 2000Gi 288
4XLarge 3 48 CPU / 128Gi 4000Gi 384

Starter is highly available

Unlike some other Ametnes data services, the MongoDB Starter tier is not a single node. It runs three members so the replica set can elect a new primary if a node fails.

Scale#

Use Modify Resource in the console to move to a larger architecture. MongoDB tiers share the same three-member topology, so a tier change does not change the replica-set layout: the existing members are resized and storage is increased per node.

To use a different MongoDB major version, provision the target version service (for example service/mongodb:9.0) and migrate the data using your normal MongoDB migration or dump/restore process. Major-version changes are a new service rather than an in-place tier change.

Create a database and application user#

Connect with mongosh, then create a database, collection and application user:

db.getSiblingDB("sales").createCollection("orders")

db.getSiblingDB("admin").createUser({
  user: "app",
  pwd: "<application-password>",
  roles: [{ role: "readWrite", db: "sales" }]
})

Application connections should use the application user rather than the admin user.

Next#