openova/platform/mongodb

MongoDB

Document database for OpenOva platform.

Status: Accepted | Updated: 2026-01-17

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Overview

MongoDB provides document database capabilities with:

• CDC (Change Data Capture) via Debezium for DR
• Replication through Redpanda
• Schema-flexible document storage
• Aggregation pipeline for analytics

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Architecture

Single Region

flowchart TB
    subgraph MongoDB["MongoDB Replica Set"]
        Primary[Primary]
        Secondary1[Secondary 1]
        Secondary2[Secondary 2]
    end

    App[Applications] --> Primary
    Primary -->|"Replicate"| Secondary1
    Primary -->|"Replicate"| Secondary2

Multi-Region DR (CDC)

flowchart TB
    subgraph Region1["Region 1"]
        MG1[MongoDB Primary]
        Debezium[Debezium]
        RP1[Redpanda]
    end

    subgraph Region2["Region 2"]
        RP2[Redpanda]
        Sink[Sink Connector]
        MG2[MongoDB DR]
    end

    MG1 -->|"CDC"| Debezium
    Debezium --> RP1
    RP1 -->|"MirrorMaker2"| RP2
    RP2 --> Sink
    Sink --> MG2

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Why CDC Instead of Native Replication

Aspect	Native Replication	CDC via Debezium
Cross-region	Complex, latency sensitive	Works over async message queue
Network tolerance	Requires stable connection	Tolerates partitions
Flexibility	MongoDB to MongoDB only	Can transform/filter
Ordering	Strict global	Per-document ordering

Decision: Use CDC for multi-region DR to leverage existing Redpanda infrastructure and improve fault tolerance.

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Configuration

MongoDB Deployment

apiVersion: mongodbcommunity.mongodb.com/v1
kind: MongoDBCommunity
metadata:
  name: mongodb
  namespace: databases
spec:
  members: 3
  type: ReplicaSet
  version: "7.0.5"
  security:
    authentication:
      modes: ["SCRAM"]
  users:
    - name: admin
      db: admin
      passwordSecretRef:
        name: mongodb-admin-password
      roles:
        - name: root
          db: admin
    - name: debezium
      db: admin
      passwordSecretRef:
        name: mongodb-debezium-password
      roles:
        - name: read
          db: local
        - name: readWrite
          db: <tenant>

Debezium Connector

apiVersion: kafka.strimzi.io/v1beta2
kind: KafkaConnector
metadata:
  name: mongodb-source
  namespace: databases
spec:
  class: io.debezium.connector.mongodb.MongoDbConnector
  tasksMax: 1
  config:
    mongodb.connection.string: mongodb://debezium:${password}@mongodb.databases.svc:27017
    mongodb.name: openova
    collection.include.list: "<tenant>.*"
    capture.mode: change_streams_update_full
    topic.prefix: cdc.mongodb

Sink Connector (DR Region)

apiVersion: kafka.strimzi.io/v1beta2
kind: KafkaConnector
metadata:
  name: mongodb-sink
  namespace: databases
spec:
  class: com.mongodb.kafka.connect.MongoSinkConnector
  tasksMax: 1
  config:
    connection.uri: mongodb://admin:${password}@mongodb.databases.svc:27017
    database: <tenant>
    topics.regex: cdc.mongodb.<tenant>.*
    change.data.capture.handler: com.mongodb.kafka.connect.sink.cdc.debezium.DebeziumCdcHandler

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Failover

Automatic (Within Region)

MongoDB replica set handles automatic primary election.

Manual (Cross-Region)

1. Stop CDC pipeline
2. Verify DR data is current
3. Promote DR MongoDB to primary
4. Update application connection strings
5. (Optional) Reverse CDC direction

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Monitoring

Metric	Description
mongodb_connections	Active connections
mongodb_op_latencies_latency	Operation latency
mongodb_repl_lag	Replication lag
debezium_streaming_lag	CDC lag

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Part of OpenOva