Designing and Implementing Azure Resiliency Architectures

Designing and implementing Azure resiliency architectures is crucial for businesses to ensure high availability and minimize downtime.

To achieve this, Azure provides a range of tools and services that can be used to design and implement resilient architectures.

Azure Active Directory (AAD) can be used to manage identities and provide access control, reducing the risk of unauthorized access to resources.

A well-designed Azure resiliency architecture can help businesses recover quickly from outages and minimize the impact of service disruptions.

By using Azure's built-in features such as load balancing and traffic management, businesses can distribute traffic across multiple instances of a service, ensuring that users always have access to the resources they need.

This approach can help reduce the risk of single points of failure and ensure that critical services remain available even in the event of an outage.

Azure storage maintains several copies of your data by default to protect against planned and unplanned outages. This is a key aspect of achieving resiliency in Azure.

To achieve resiliency in Azure, you need to consider your application design and identify the access pattern for storage. This includes noting whether your application needs read access from secondary storage or if the application needs data to be replicated to a different region for disaster recovery.

Azure offers a range of data resiliency capabilities, including automated protection and disaster recovery for virtual machines through Azure Site Recovery. This feature helps businesses ensure minimal downtime in case of an unexpected event.

Cloud Transparency is a crucial aspect of Azure Resiliency. It's essential to ensure that your cloud setup isn't a black box.

To achieve this, you can take advantage of optional Azure services and features that enable built-in resilience. This means you can focus on specific reliability goals without having to build everything from scratch.

Monitoring your cloud is a great way to identify and diagnose anomalies. This helps you track performance and optimize reliability in the long run.

With monitoring tools, you can ensure that your cloud setup is transparent and reliable. This means you can make data-driven decisions to improve performance and reduce downtime.

Standard resiliency in ExpressRoute is a single circuit with two connections configured at a single site. This configuration is also known as single-homed as it represents users with an ExpressRoute circuit configured with only one peering location.

This setup offers built-in redundancy (Active-Active) to facilitate failover across the two connections of the circuit. However, if a failure happens at this site, users might experience loss of connectivity to their Azure workloads.

ExpressRoute offers two connections at a single peering location, but this configuration is considered the least resilient and not recommended for business or mission-critical workloads because it doesn't provide site resiliency.

Here's a comparison of the different ExpressRoute resiliency options:

As you can see, Standard Resiliency is the least resilient option, but it's still a good starting point for smaller workloads or non-critical applications. However, for business and mission-critical workloads, it's recommended to opt for High Resiliency or Maximum Resiliency for added site diversity and redundancy.

To achieve high availability and resiliency, it's essential to design your architecture with multiple layers of redundancy. Consider using Azure's built-in features such as Azure Load Balancer to distribute incoming traffic across multiple instances.

Azure provides several options for storage resiliency, including Locally Redundant Storage (LRS), Zone-Redundant Storage (ZRS), and Geo-Redundant Storage (GRS). Each option offers a different level of redundancy and availability, with LRS providing 11 nines of resiliency, ZRS offering 12 nines, and GRS providing 16 nines.

When designing for disaster recovery, consider setting up ExpressRoute circuits in multiple peering locations and regions. This will allow you to create a robust backend network connectivity for disaster recovery.

Azure's Geo-Zone-Redundant Storage (GZRS) combines cross-zone high availability within a region with an added level of protection against regional outages thanks to geo-replication. This option provides an SLA of 16 nines over the course of a year.

To evaluate the resiliency of multi-site redundant ExpressRoute circuits, ensure that on-premises routes are advertised over the redundant circuits to fully utilize the benefits of multi-site redundancy.

Here are some key considerations for designing resilient architectures in Azure:

Remember to consider the specific needs of your application and workload when selecting the right storage option for your Azure architecture.

You can enable built-in resilience by taking advantage of optional Azure services and features to achieve your specific reliability goals.

Azure Service Health is a customizable dashboard that helps you identify resource issues and resolve them. You can view planned and past maintenance in the Azure portal, as well as configure alerts and notifications that suit your needs.

ClearBank, a company that builds infrastructure resilience, customer trust, and competitive value, relies on Azure services to ensure end-to-end reliability and resiliency. They get the tools from Azure and set up the systems and processes to put it all together.

ExpressRoute circuit maintenance notifications can be configured through Azure Service Health, which also allows you to view planned and past maintenance. You can set alerts within Service Health to be notified of upcoming maintenance.

To ensure data protection, consider using Azure Backup for SQL Server workloads using DPM, especially if you're already using Azure Backup to back up your VMs. This approach provides a unified recovery procedure for VMs and SQL Server.

Service Health is a crucial aspect of Azure Services for Resiliency, allowing you to identify and resolve resource issues quickly. With Azure Service Health, you can view planned and past maintenance, as well as configure alerts and notifications for ExpressRoute circuit maintenance.

Azure Service Health provides a customizable dashboard to help you stay on top of resource issues. You can use this dashboard to identify resource issues and resolve them promptly, minimizing downtime and ensuring high availability.

ExpressRoute uses Azure Service Health to notify you of planned and upcoming ExpressRoute circuit maintenance. This allows you to plan ahead and take necessary steps to minimize disruptions.

To stay informed about ExpressRoute circuit maintenance, you can configure service health alerts. This will notify you of upcoming maintenance and help you plan accordingly.

Here are some key benefits of using Azure Service Health:

By leveraging Azure Service Health, you can ensure that your Azure resources are running smoothly and that you're always aware of any potential issues. This helps to maintain high availability and minimize downtime, ensuring that your applications and services are always accessible to your users.

Cognitive Search is a powerful tool that requires careful planning to ensure high availability and resilience. It's essential to provision multiple replicas to ensure that your service remains operational even in the event of datacenter outages.

Use at least two replicas for read high-availability, or three for read-write high-availability. This approach helps prevent data loss and ensures that your service is always accessible.

Zone redundancy is also crucial for Cognitive Search. Deploying replicas across multiple availability zones helps your service remain operational even when datacenter outages occur.

Reliability in Azure Cognitive Search provides more information on how to implement zone redundancy effectively.

To ensure continuity in indexing, configure indexers for multi-region deployments. If your data source is geo-replicated, you should point each indexer to its local data source replica.

However, if your data source is not geo-replicated, point multiple indexers at the same data source. This approach ensures that Azure Cognitive Search services in multiple regions continuously and independently index from the data source.

Here's a summary of the best practices for configuring indexers for multi-region deployments:

Monitoring is key to ensuring the reliability of your Azure setup. Azure Monitor collects telemetry data from Azure and on-premises environments.

To keep a close eye on your ExpressRoute circuits, configure Network Insights within Azure Monitor. This will give you a comprehensive view of all ExpressRoute circuit metrics, including ExpressRoute Direct and Global Reach.

Visualizing topologies and dependencies for peerings, connections, and gateways can be done within the circuits card. This is especially useful for understanding the flow of data through your circuits.

Availability, throughput, and packet drops are just a few of the insights available for circuits. These metrics will help you identify potential issues before they become major problems.

To ensure your ExpressRoute Gateway is running smoothly, set up monitoring using Azure Monitor. This will give you real-time data on gateway availability, performance, and scalability.

With multiple gateway metrics at your disposal, you'll be able to better understand the performance of your gateway. This information will help you make informed decisions about your Azure setup.

Monitoring and triggering failovers is a critical aspect of maintaining the stability and reliability of any system. Automated monitoring tools can constantly check the health and performance of your system, alerting you to any issues in real-time.

It's essential to establish clear thresholds for triggering failovers, so you have a predetermined plan in place for when to switch over to a backup system. This helps minimize downtime and ensure your system remains operational.

Regular testing of failover procedures is also crucial. Conducting simulated failover exercises can help identify areas for improvement and ensure that your system responds as intended.

Having a robust and reliable backup system in place is vital for successful failovers. This backup system should be regularly maintained and tested to ensure it's ready to take over in case of a failure.

Azure provides optional services and features to achieve your specific reliability goals. By taking advantage of these, you can design and operate your mission-critical applications with confidence.

The Azure Well-Architected Framework is a set of guiding tenets across five core pillars: reliability, security, performance efficiency, cost optimization, and operational excellence. This framework can help you optimize an existing application on Azure.

Here are some key recommendations for ensuring high availability, resiliency, and reliability in your ExpressRoute network architecture:

Site Reliability Engineering (SRE) is a discipline that helps organizations achieve the appropriate level of reliability in their systems, services, and products. This approach can be applied to Azure infrastructure, where ongoing Microsoft investments prioritize transparency and quick action during service issues.

The Azure Well-Architected Framework provides a set of guiding tenets across five core pillars, including reliability, security, performance efficiency, cost optimization, and operational excellence. By following this framework, you can design and operate mission-critical applications with confidence.

AIOps plays a critical role in continuous monitoring of health metrics, empowering DevOps engineers to detect issues early and make rollout or rollback decisions based on impact scope and severity. This is especially important for large distributed systems, where resiliency threat modeling can help prevent outages.

Site Reliability Engineering (SRE) is a discipline that helps organizations achieve the appropriate level of reliability in their systems, services, and products.

Microsoft Azure prioritizes transparency, keeping you informed and able to act quickly during service issues. This is a fundamental aspect of SRE, where continuous monitoring of health metrics is crucial.

The University of Miami uses Azure to drive reliability, thinking creatively about how to implement cloud solutions that make them more resilient and flexible. This is a key benefit of SRE, where organizations can leverage the cloud to improve their systems' reliability.

Azure uses AI and machine learning to empower DevOps engineers, monitor the deployment process at scale, detect issues early, and make rollout or rollback decisions based on impact scope and severity. This is a powerful tool in SRE, where automation and data analysis can help prevent downtime and improve overall system reliability.

GEP improved the reliability of its logistics platform by using AKS or Azure Kubernetes Service, which allows for automatic failover to a second availability zone in case of a primary node pool failure. This is a practical application of SRE principles, where organizations can use cloud services to build more resilient systems.

The Microsoft network connects over 60 Azure regions, 300+ Azure datacenters, 190 edge sites, and over 175,000 miles of terrestrial and subsea fiber worldwide, making it a robust platform for SRE.

Site reliability is crucial for any organization, and Azure offers various solutions to ensure high availability and resiliency.

The Microsoft network connects more than 60 Azure regions, 300+ Azure datacenters, 190 edge sites, and over 175,000 miles of terrestrial and subsea fiber worldwide, providing a robust foundation for site reliability.

Azure Site Recovery allows you to replicate on-premises and Azure workloads from a primary site to a secondary location, ensuring business continuity in case of outages or disasters.

There are three ExpressRoute resiliency architectures to choose from: Maximum Resiliency, High Resiliency, and Standard Resiliency. These architectures ensure high availability and resiliency in your network connections between on-premises and Azure.

Here are the key features of each ExpressRoute resiliency architecture:

Disaster Recovery and Business Continuity are crucial for any organization that wants to minimize downtime and data loss. Azure Site Recovery can replicate on-premises and Azure workloads from a primary site to a secondary location, ensuring business continuity.

To maximize availability, both customer and service provider segments on your ExpressRoute circuit should be architected for availability and resiliency. This means planning for scenarios such as regional service outages due to natural calamities.

A robust disaster recovery design is essential for multiple circuits configured through different peering locations in different regions. This can be achieved by implementing a disaster recovery plan that covers various scenarios.

Site Reliability Engineering (SRE) can help organizations achieve the right level of reliability in their systems, services, and products. By using SRE, you can ensure that your systems are designed to be highly available and resilient.

To learn more about designing for disaster recovery, check out the recommended article. This will provide you with detailed information on how to create a robust disaster recovery design for your ExpressRoute circuit.

Azure's built-in redundancy is a game-changer for resiliency. It maintains several copies of your data by default, depending on the storage type selected. This means you have multiple safeguards against data loss, even in the event of a disaster.

ClearBank's Chief Technology Officer, Tom Harris, emphasizes the importance of teamwork in achieving end-to-end reliability and resiliency. He works with Azure to set up systems and processes that put it all together.

The number of data copies and their location depends on the storage type. This tradeoff has to be evaluated before selecting the storage type, as it directly impacts costs.

To achieve resiliency in Azure, consider utilizing optional Azure services and features to achieve your specific reliability goals, such as Network Watcher, which monitors, diagnoses, and provides insights into network performance and health.

Network Watcher can help you identify and troubleshoot network issues, ensuring your applications and data are always available.

ClearBank's Chief Technology Officer, Tom Harris, emphasizes the importance of a team effort in ensuring end-to-end reliability and resiliency, highlighting the need for setting up systems and processes to put Azure tools together.

Azure regions are an integral part of your ExpressRoute design and resiliency strategy, and utilizing availability zones can achieve higher availability and resilience in your deployments.

Availability zones protect applications and data from data center failures by spanning across multiple physical locations within a region.

Regions and availability zones are central to your application design and resiliency strategy, and deploying your ExpressRoute Virtual Network Gateways as zone-redundant across availability zones within a region provides resiliency, scalability, and higher availability for accessing mission-critical services on Azure.

To evaluate the resiliency of multi-site redundant ExpressRoute circuits, it's essential to ensure that on-premises routes are advertised over the redundant circuits to fully utilize the benefits of multi-site redundancy.

Plan to establish multiple paths between the on-premises edge and the peering locations to achieve better resiliency, and ensure redundancy within your on-premises network and service provider to avoid single points of failure.

Microsoft recommends operating both connections of an ExpressRoute circuit in active-active mode to improve resiliency and availability, allowing two connections to operate in this mode and load balancing network traffic across the connections on a per-flow basis.

To maximize availability, both the customer and service provider segments on your ExpressRoute circuit should be architected for availability & resiliency, and plan for disaster recovery scenarios such as regional service outages due to natural calamities.

Setting up geo-redundant ExpressRoute circuits can create a robust backend network connectivity for disaster recovery, and using site-to-site VPN as a backup solution for ExpressRoute connectivity is not recommended for latency-sensitive, mission-critical, or bandwidth-intensive workloads.

Configure gateway health monitoring & alerting using Azure Monitor for ExpressRoute Gateway availability, performance, and scalability, and deploy Azure Load Balancer with at least two instances in the backend to avoid single points of failure.

Provision at least two instances of Azure Load Balancer to ensure resiliency, and use outbound rules to prevent connection failures due to Source Network Address Translation (SNAT) port exhaustion.