When it comes to running Oracle databases in the cloud, most people immediately think of Oracle Cloud Infrastructure (OCI). However, Oracle databases can also thrive on Microsoft Azure, offering a unique set of advantages and challenges. In this blog, we will explore high availability and disaster recovery strategies for Oracle Database on Azure and shed light on some best practices.
Oracle and Azure: A Powerful Combination
Azure might not be the first choice that comes to mind when considering Oracle deployments, but it has been a viable option for over five years. Azure’s investment in Linux, which accounts for around 60% of workloads on the platform, makes it a solid choice for Oracle workloads. Azure offers various flavors of Linux, including Oracle Linux and Red Hat, ensuring flexibility for Oracle users.
Customization and Choice
One of the key benefits of Azure is the ability to customize your Oracle environment to your exact specifications. You can start with base images provided by Oracle and then fine-tune them to meet your specific requirements before adding them to your image gallery. This level of customization can be a significant advantage when running Oracle workloads.
Azure’s Strengths for Oracle Workloads
Azure provides a robust infrastructure for Oracle databases, including various VM SKUs tailored for Oracle workloads. Here are some noteworthy features:
Azure VM Series: Built for Oracle
Microsoft’s D-series are great entry level VMs for relational workloads, whereas the M-series offers high vCPU and memory options for transactional workloads. The span of the E-series is targeted for the majority of Oracle workloads, like the Eds v5 VM SKUs which come standard with Intel Ice Lake chips for high performance vCPU, including constrained CPU versions which have high memory and IO limits while lower vCPU counts to save on licensing costs. These VMs are optimized for exceptional performance and reliability, making them ideal choices for running Oracle databases.
Networking and Connectivity
Azure’s networking capabilities ensure seamless connectivity for Oracle workloads. ExpressRoute, for instance, provides high-speed, private network connections to Azure, minimizing latency and enhancing performance.
Region and Availability Zone Redundancy
Azure offers a wide range of regions and availability zones, allowing you to design high availability and disaster recovery strategies tailored to your needs. Distributing your Oracle workloads across multiple regions and availability zones can help ensure maximum uptime.
Proximity Placement Groups
Proximity Placement Groups enable you to group related resources closely together within the same data center, reducing latency and optimizing network performance. This is crucial for Oracle workloads where low latency is a priority.
Best Practices for High Availability
Ensuring high availability for Oracle Database on Azure requires careful planning and adherence to best practices. Here are some key recommendations:
Understand Your RPO and RTO
Before implementing high availability and disaster recovery solutions, define your Recovery Point Objective (RPO) and Recovery Time Objective (RTO). These metrics will guide your strategy and help you choose the right technologies and configurations.
Leverage Azure’s Redundancy Features
Azure offers various redundancy features, including availability zones and proximity placement groups. Make full use of these capabilities to design a resilient architecture that can withstand failures.
Implement Data Guard
Oracle Data Guard is a valuable tool for ensuring data availability and disaster recovery. Configure Data Guard to replicate your primary database to a secondary location, allowing for seamless failover in case of a disaster.
Optimize Network Configuration
Thoroughly assess your network configuration to minimize latency and maximize performance. Use tools like ExpressRoute to establish fast, private connections between your on-premises infrastructure and Azure.
Regularly Test Failovers
Don’t wait until a real disaster occurs to test your failover procedures. Include failover testing as part of your regular maintenance and ensure that your team is well-prepared to execute the process smoothly.
Consider Backup Strategies
Backup strategies can play a crucial role in high availability. Azure provides snapshot capabilities that allow you to create copies of your VMs quickly. Explore various backup methods, such as snapshot-based backups, to ensure data protection.
Understanding Oracle’s licensing agreements is essential when running Oracle Database on Azure. Oracle’s licensing terms may vary, and it is crucial to ensure that your deployment complies with Oracle’s requirements. Azure’s flexibility allows you to tailor your Oracle environment while staying within licensing boundaries.
Backup and Recovery in Azure
Many organizations transitioning Oracle Database to Azure often face unexpected challenges when it comes to backup and recovery. Azure’s vast ecosystem and versatile services require careful planning. A common pitfall is hitting throttling thresholds, which can drastically affect backup and recovery processes.
Understanding Your Workload: Before migrating to Azure, thoroughly assess your workload’s needs. Azure offers a range of services and features that can accommodate various requirements. It’s essential to anticipate demand and resource usage to avoid bottlenecks during backup and recovery.
Tailoring Backup Strategies: Your on-premises backup strategies may not be suitable for Azure. Consider options such as incremental ARM-based backups and adjustments to thresholds, statistical sampling rates, and batch loads versus backups. With Azure’s primary and secondary configurations, you can explore alternatives to mitigate resource constraints.
Storage Choices Matter: The choice of storage impacts backup duration. Small databases can leverage Azure Blob Storage but ensure adequate write speed to the destination. Medium-sized databases might benefit from Azure Files Premium, but remember it is remote storage, which may require premium SSDs. Optimize storage costs by aging out backups and moving them to cost-effective tiers.
When RMAN Is not an Option
For exceptionally large databases, traditional backup methods may not suffice. Azure offers volume snapshots, but not all snapshots are equal. Some high IO solutions like Silk provide more robust volume snapshot capabilities. These solutions enable snapshot recovery, log application, and log reset, with archived logs managed separately, often by RMAN or similar tools. Silk also provides thin snapshot replication of secondary environments which can be used for RMAN backups when required, but still avoiding the RMAN IO impact on the production system.
Comprehensive Environment Assessment
Moving to the cloud involves more than just migrating the database. Consider the entire ecosystem, including middleware, application hosts, script servers, network, firewall, and load balancers. Understand the implications of changes in network topology, such as transitioning from Data Guard to load balancers.
Sizing for Success: Properly sizing your resources is essential. The Automatic Workload Repository (AWR) is a valuable tool that provides data for right sizing your environment. Simulate peak workloads using the 12 data points from AWR to ensure that your Azure resources align with your actual workload. This step helps avoid overprovisioning and ensures cost-effectiveness.
Oracle Databases Don’t Stand Alone: Remember that Oracle databases are part of a broader ecosystem. Evaluate the entire environment, including middleware, hosts, and network configurations. Whitepapers and Azure documentation can guide you through these assessments. When conducting assessments, focus on sizing your databases correctly, and be cautious about migrating Exadata workloads.
In conclusion, running Oracle Database on Azure offers numerous benefits, including scalability, flexibility, and robust networking capabilities. By carefully planning your high availability and disaster recovery strategy, optimizing your network configuration, and adhering to best practices, you can create a resilient Oracle environment that meets your business needs and ensures data availability, even in the face of unexpected challenges. Remember that Azure provides a powerful platform for running Oracle workloads, and with the right approach, you can harness its capabilities to achieve maximum availability and reliability. Additionally, optimizing Oracle database backup and recovery in Azure requires meticulous planning and evaluation. Ensure that your backup and recovery strategies align with your Azure environment, focusing on workload needs rather than replicating on-premises hardware, and use robust sizing assessments to match your Azure resources with your actual requirements. Building a resilient architecture with redundancy for critical components is key to a successful cloud migration. With proper planning and assessment, your cloud project can become more viable, cost-effective, and aligned with your business needs.
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