Database-Geo-Replication-Strategies

Author: Ameen-Alam

06_daca_deployment_guide/01_Prototype-Deployment-Serverless/xx-Infrastructure-Setup/Database-Geo-Replication-Strategies.md

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+# Database Geo-Replication Strategies
+
+## Overview
+This document outlines the geo-replication strategies for our databases, including the transition plan from managed services to self-hosted Kubernetes deployments.
+
+## Current Managed Services (Phase 1)
+- CockroachDB Serverless (to be transitioned to Postgres on Kubernetes)
+- Upstash Redis (to be transitioned to Redis on Kubernetes)
+- CloudAMQP RabbitMQ (to be transitioned to Kafka)
+
+## Postgres Replication (Phase 2)
+
+### Primary-Secondary Replication
+- Primary cluster in US-East
+- Secondary cluster in US-West
+- Synchronous replication for critical data
+- Asynchronous replication for non-critical data
+
+### Configuration
+```yaml
+apiVersion: postgresql.cnpg.io/v1
+kind: Cluster
+metadata:
+  name: postgres-primary
+spec:
+  instances: 3
+  primaryUpdateStrategy: unsupervised
+  replication:
+    mode: synchronous
+    syncReplicas: 2
+```
+
+## Redis Replication (Phase 2)
+
+### Master-Slave Replication
+- Master node in US-East
+- Slave nodes in US-West
+- Redis Sentinel for automatic failover
+- Read replicas for scaling read operations
+
+### Configuration
+```yaml
+apiVersion: redis.redis.opstreelabs.in/v1beta1
+kind: Redis
+metadata:
+  name: redis-master
+spec:
+  mode: cluster
+  cluster:
+    replicas: 2
+    nodes: 3
+  storage:
+    type: persistent
+    size: 10Gi
+```
+
+## Transition Plan
+
+### Phase 1: Managed Services
+1. CockroachDB Serverless
+   - Use for initial development and testing
+   - Implement data migration strategy
+   - Document schema and queries
+
+2. Upstash Redis
+   - Use for caching and session management
+   - Prepare Redis data migration plan
+   - Document key patterns and TTLs
+
+3. CloudAMQP RabbitMQ
+   - Use for message queuing
+   - Plan Kafka migration
+   - Document queue configurations
+
+### Phase 2: Kubernetes Deployment
+1. Postgres Migration
+   - Set up Kubernetes Postgres cluster
+   - Implement data migration
+   - Test replication and failover
+   - Switch traffic gradually
+
+2. Redis Migration
+   - Deploy Redis cluster on Kubernetes
+   - Migrate data from Upstash
+   - Test replication and failover
+   - Switch traffic gradually
+
+3. Kafka Migration
+   - Deploy Kafka on Kubernetes
+   - Migrate from RabbitMQ
+   - Test message processing
+   - Switch traffic gradually
+
+## Health Monitoring
+- Prometheus metrics for both Postgres and Redis
+- Custom health checks for replication status
+- Alerting on replication lag
+- Automated failover testing
+
+## Backup Strategy
+- Daily snapshots of both databases
+- Point-in-time recovery capability
+- Cross-region backup storage
+- Automated backup verification
+
+## Migration Checklist
+- [ ] Document current database schemas
+- [ ] Create data migration scripts
+- [ ] Set up monitoring for both environments
+- [ ] Implement rollback procedures
+- [ ] Schedule maintenance windows
+- [ ] Test failover scenarios
+- [ ] Update application configurations
+- [ ] Update CI/CD pipelines