CMS Platform Plus tier

Optimizely CMS Platform Plus is an optional premium tier with several high-availability redundancy options and a premium service bus. The following sections describe these features included in one high-availability bundle (not sold separately). To order this tier, contact your customer service manager (CSM) or account executive (AE).

• Zone redundancy provides high availability and fault tolerance for your production environments.
• Regional redundancy (formerly known as Automatic Failover) is best when you need protection against failures in entire regions.
• The Premium service bus provides dedicated resources, predictable latency, and high throughput, ideal for load testing and high-scale production environments. It addresses common customer requests around scale, performance, and availability for mission-critical applications.

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Note

Combining zone and regional redundancy in one package provides the best availability. Having this package with both redundancy options gives you a 99.9% per service-level agreement (SLA).

Zone redundancy

Zones are a separate group of data centers within an Azure Region, connected by a high-performance network with a round-trip latency of less than two milliseconds. Zones have independent power, cooling, and networking infrastructure. When leveraging zone redundancy, Azure resources in the production environment are spread across multiple zones in the same Azure Region.

Zone redundancy offers several benefits for your production environments:

• Enhanced high availability – By distributing resources across multiple availability zones, Azure ensures the continuous availability of your applications even in the face of unexpected failures or maintenance activities. It automatically balances the load and traffic across multiple availability zones and automatically syncs the data and state across multiple availability zones. You do not need to configure any additional routing rules. This redundancy minimizes downtime and ensures uninterrupted service delivery to users.
• Improved fault tolerance – Utilizing multiple availability zones reduces the risk of a single point of failure. It automatically scales up and down based on the demand and capacity of each availability zone. In the event of issues in one zone, traffic can automatically fail over to resources in another zone, guaranteeing uninterrupted operation and mitigating potential service disruptions.
• Built-in disaster recovery – With resources replicated across multiple availability zones, Azure provides built-in disaster recovery capabilities. In the event of a catastrophic failure, applications can automatically fail over to resources in another zone, ensuring business continuity and minimizing data loss.

Baseline redundancy and backups

In production, service instances are configured with local zone redundancy. This means multiple copies of resources and data are kept within the same area to ensure reliability, so if one part fails, others can keep things running smoothly.

Backups of code, configuration, and data are kept on Read Access-Georedundant Storage (RA-GRS) and are replicated to the primary region's region pair.

• Application changes are backed up when they occur (for example, after each deployment).
• Automatic backup every 24 hours

In addition to the core platform disaster recovery capabilities, you can increase availability with zone and regional redundancy.

Optimizely CMS Platform Plus service bus

The Optimizely CMS Platform Plus option provides dedicated resources, predictable latency, and high throughput, ideal for load testing and high-scale production environments. It addresses common customer requests around scale, performance, and availability for mission-critical applications.

Regional redundancy (formerly Automatic Failover)

Regional redundancy lets you maintain high availability in the event of an outage in an infrastructure component in a data center or even an entire data center region. 

When you use regional redundancy, your environment benefits from the following effects:

• Your data exists in two regions.
• The site enters read-only (not write mode) during failover, which means your site cannot continue receiving orders or other data while you are in the secondary region.
• Failover happens slower than zone redundancy because the secondary region is inactive unless needed.
• You remain protected if an entire region, or single zone, or any app components fail.

Regional redundancy prevents websites from going down in the event of a server failure. An error on a primary server is detected automatically, and traffic is automatically routed to a backup server in a secondary geographically redundant location within the same delivery region.

Regional redundancy in DXP is fully automatic, with no manual intervention. Geo-replication is included by default, meaning traffic is sent to a backup server in a different location in case of a data center outage, providing redundancy across geographical regions.

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Note

Optimizely CMS Platform Plus is not available in the following regions:

• Norway East
• UAE North
• Sweden Central
• Canada East
• Australia Southeast
• West US

Regional redundancy architecture

The set up includes two application environments, where storage is replicated from the primary to the secondary (failover) environment. Optimizely ensures that the failover Web App is in the same state as the primary one.

Regional redundancy mechanism

The Web App endpoints are continuously checked for responses. If one stops responding, traffic is moved to the secondary Web App. When the primary Web App works again, traffic is directed back. You can display a message informing that the site is in read-only mode.

Regional redundancy configuration

DXP includes built-in endpoint monitoring and automatic endpoint failover. To use regional redundancy, you must update the website configuration to handle all hosts (*) or add the regional redundancy hostname. This is done in the Optimizely Admin view. See the following example.

Considerations

Consider the following points when using regional redundancy with Optimizely:

• Reduce the cache expiration to avoid displaying outdated content on the regional redundancy Web App in case of failure.
• Ensure your Optimizely Content Management System (CMS) and Optimizely Commerce Connect versions on your site support Read-Only mode (CMS 9.7.0 and Commerce Connect 9.9.0 or higher).
• Verify that add-ons on the site support read-only mode.
• Prepare your site to handle aggressive autoscaling, which starts multiple instances before reaching maximum load. This can affect sites that make many external calls during startup. Configure warnings and application logic to handle read-only mode without triggering write exceptions (for example, when saving forms or resizing images).
• Configure warnings in your solution to handle read-only mode, such as using application state. Database transaction features, such as saving a posted form, or storage transaction features, like image resizing, must be aware that the application is in read-only mode so as not to throw write exceptions.
• Optionally, configure whether to display an information message to end-users on the failover site when in read-only mode during a failure. See the Find database mode by code section in the Database mode documentation.

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Important

When the site is in failover state, the used storage is read-only.

See the related blog post titled Episerver’s Digital Experience Cloud™ Automatic Failover Solution by Daniel Browne (now called Optimizely Digital Experience Platform) for information.