Application downtime for mission-critical services can directly impact your reputation and bottom line. To avoid that, you need to be able to deploy regionally resilient workloads that detect and automatically recover from failures. But setting up multi-region, highly available deployments often involves complex configurations, and responding to incidents or outages is usually a manual process. 

Multi-region services on Cloud Run provide a one-command approach to deploying the same service configuration across multiple regions. When deployed with a global external application load balancer, you can serve traffic from different regions.

Now, we’ve made it easier to detect regional service disruptions and automatically fail over to a healthy region within seconds with new capabilities:

  1. Readiness probes provide instance-level health checks for your Cloud Run service to determine exactly when your containers are ready to serve traffic. You can also use these probes to monitor how many healthy or unhealthy instances exist for your service in each region.

  2. Service health aggregates instance-level health checks from readiness probes to calculate the health of your service in each region. This aggregate health is exposed via serverless network endpoint groups (NEGs) in each region. When your service is connected to a global application load balancer, traffic automatically fails away from regions with unhealthy services. Service health can be used with both single and multi-region services.

Let’s take a closer look at some scenarios where these new capabilities can come in handy.

Use cases

To make your Cloud Run applications highly available, it is essential to minimize the downtime for each incident. In high availability scenarios, readiness probes can help you detect regional service failures and automatically fail over, minimizing service degradation or disruptions. 

To achieve automated failover, one key thing to consider is whether you plan to support application traffic from the public internet or from within your private network (VPC).

  • Public internet applications: When you have a public-facing website or API, configure Cloud Run with a global external application load balancer for automatic detection and failover capabilities. 

  • Private network applications: When you have private applications with internal traffic, configure Cloud Run with a cross-regional internal application load balancer for automatic detection and failover capabilities. 

Design Considerations

Cloud Run’s new service health excels at quickly detecting and recovering outages in active-active configurations, where two or more regions are actively configured to serve traffic. Some things to consider when designing your multi-region setup:

  • Single points of failure: As you design your application, ensure that each layer of your application, including your database layer, has regional redundancies to avoid any single points of failure. For three-tiered applications on Cloud Run, consider setting up your web tier and application tier with distinct multi-region architectures to handle public internet and private networking respectively.

  • Data replication: When replicating data across regions and evaluating your recovery point objective (RPO), consider whether you require zero data loss. Cloud Run service health works best with read- and write-heavy applications that actively synchronize data across regions. 

  • Data residency: Google Cloud offers several multi-region database configurations with managed multi-region solutions including Firestore, Spanner, Cloud Storage, and Cloud SQL. These all work great for multi-region architectures on Cloud Run that have strict data sovereignty requirements.

Get started

Cloud Run’s enhanced multi-region high availability services are currently available in all Cloud Run regions at no additional cost. You only pay for the standard CPU and memory required to run the readiness probes. To learn more, check out our documentation.

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