MongoDB

Versions

Version	Status	Notes
8	Available	Recommended
7	Available
6	Available

Connecting

Parameter	Value
Host	{name}.db.foundrydb.com
Port	27017
Default database	defaultdb
TLS	Required

mongosh "mongodb://USER:PASS@HOST:27017/defaultdb?tls=true"

Full connection string examples: Connection Strings →

Replica Sets

All MongoDB services run as a 3-member replica set by default, providing:

• Automatic failover if the primary goes down
• Read preference routing (secondaryPreferred, nearest)
• Oplog-based point-in-time recovery

The replica set name is returned in the service detail response:

curl -u admin:password https://api.foundrydb.com/managed-services/{id} \
  | jq '.replica_set_name'

Use it in your connection string for proper topology awareness:

mongodb://USER:PASS@HOST:27017/defaultdb?tls=true&replicaSet=rs0

Add Nodes

Scale to a 5-member replica set for higher read throughput:

curl -u admin:password -X POST \
  https://api.foundrydb.com/managed-services/{id}/nodes \
  -H "Content-Type: application/json" \
  -d '{"role": "replica"}'

Failover

Manual failover to a specific secondary:

curl -u admin:password -X POST \
  https://api.foundrydb.com/managed-services/{id}/nodes/{node_id}/failover

Automatic failover happens within ~10 seconds if the primary becomes unreachable. Your driver will reconnect automatically.

Point-in-Time Recovery

Continuous oplog archiving. Restore to any timestamp:

curl -u admin:password -X POST \
  https://api.foundrydb.com/managed-services/{id}/backups/restore \
  -H "Content-Type: application/json" \
  -d '{
    "restore_point": "2026-03-15T14:30:00Z",
    "target_service_name": "my-mongo-restored"
  }'

Configuration

curl -u admin:password -X PATCH \
  https://api.foundrydb.com/managed-services/{id}/configuration \
  -H "Content-Type: application/json" \
  -d '{
    "parameters": {
      "operationProfiling.slowOpThresholdMs": "100",
      "operationProfiling.mode": "slowOp"
    }
  }'

Common parameters:

Parameter	Default	Description
operationProfiling.mode	off	Profiling: off, slowOp, all
operationProfiling.slowOpThresholdMs	100	Slow op threshold in ms
net.maxIncomingConnections	65536	Max connections

Indexes

Create indexes via the shell or driver to improve query performance:

// Compound index
db.orders.createIndex({ userId: 1, createdAt: -1 });

// Text search index
db.articles.createIndex({ title: 'text', body: 'text' });

// TTL index (auto-expire documents)
db.sessions.createIndex({ createdAt: 1 }, { expireAfterSeconds: 3600 });

Metrics

curl -u admin:password \
  "https://api.foundrydb.com/managed-services/{id}/metrics?metric=connections&period=1h"

Key metrics: connections, opcounters, replication_lag, wiredtiger_cache_used.

Backups

# List backups
curl -u admin:password https://api.foundrydb.com/managed-services/{id}/backups

# Manual backup
curl -u admin:password -X POST \
  https://api.foundrydb.com/managed-services/{id}/backups \
  -H "Content-Type: application/json" \
  -d '{"backup_type": "manual"}'