### Module 8: Operational Best Practices
#### Lesson 1: Routine Maintenance and Health Checks
**Objective**: Teach participants how to conduct routine maintenance and health checks to ensure the optimal performance and stability of OpenSearch clusters.
**Topics**:
- **Maintenance Overview**: Importance of regular maintenance for the longevity and efficiency of OpenSearch clusters.
- **Health Check Tools and Metrics**: Introduction to tools and metrics for monitoring cluster health, including CPU, memory usage, disk I/O, and node availability.
- **Automating Health Checks**: How to automate health checks using scripts or cloud service features to regularly assess cluster status.
- **Addressing Common Issues**: Strategies for identifying and resolving common issues detected during health checks, such as unbalanced shards, hardware failures, or configuration errors.
#### Lesson 2: Upgrading and Migrating Clusters
**Objective**: Provide a comprehensive guide on safely upgrading and migrating OpenSearch clusters to new versions or infrastructure with minimal downtime.
**Topics**:
- **Planning Upgrades**: Steps for planning an OpenSearch cluster upgrade, including compatibility checks and staging environment tests.
- **Rolling Upgrades**: Detailed process for performing a rolling upgrade, minimizing downtime while updating nodes to a new version.
- **Migration Strategies**: Options and best practices for migrating OpenSearch data to a new cluster or cloud environment, including snapshot and restore techniques.
- **Post-Upgrade/Migration Tasks**: Validation tests to ensure the cluster operates as expected after an upgrade or migration.
#### Lesson 3: Cost Management and Optimization
**Objective**: Explore strategies for managing and optimizing the costs associated with running OpenSearch clusters, without sacrificing performance.
**Topics**:
- **Cost Analysis**: Understanding the cost components of running an OpenSearch cluster, including compute, storage, and data transfer expenses.
- **Optimization Techniques**: Practical tips for reducing costs, such as rightsizing instances, leveraging reserved instances or savings plans, and optimizing storage and indexing strategies.
- **Monitoring and Alerting for Costs**: Setting up monitoring for cost-related metrics and configuring alerts to prevent cost overruns.
- **Cost vs. Performance Trade-offs**: Balancing cost optimization efforts with performance requirements, ensuring that cost-saving measures do not negatively impact cluster efficiency or availability.