Solution Patterns: Minimize Downtime when Migrating from Hypervisors to OpenShift Virtualization
Migrating applications from one platform to the other requires a thoughtful, phased approach. For example, let’s consider an enterprise that is transitioning from traditional hypervisor solutions like VMware vSphere to OpenShift Virtualization. Factors such as application dependencies, regulatory compliance, budget constraints, and resource availability often necessitate a phased migration approach to minimize disruption and maximize the benefits. This gradual shift allows organizations to mitigate risks and ensure continuity while migrating to OpenShift virtualization. The traffic switchover from services running on existing hypervisor platforms to OpenShift Virtualization must be disruption-free with zero downtime. Additionally, connectivity to the existing VMs in the hypervisor needs to be maintained until all components are migrated.
This solution pattern demonstrates how a locationless connectivity solution enabled by Red Hat Service interconnect can be leveraged for a disruption free migration and switchover between environments (Vmware to Openshift Virtualization in this example) with almost zero downtime.
Contributors: Vamsi Ravula (Red Hat)
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Solutions Patterns help you understand the art of the possible with Red Hat’s portfolio, and not intended to be used as is for production environments. You are welcome use any part of this solution pattern for your own workloads. |
1. Use cases
Though this pattern deals with moving applications and services, from traditional hypervisor platforms such as VMware to OpenShift virtualization, the same concepts can be applied to number of other use cases such as the ones listed below:
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Migration from an older version of OpenShift/Kubernetes to a newer version. Ex: OpenShift 3 to 4 migration
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Distributing and moving services across multiple kubernetes clusters (cloud or on-prem)without any downtime
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Moving applications across different kubernetes offerings. Ex: Vanilla kubernetes to OpenShift, AKS/EKS to OpenShift
2. The story behind this solution pattern
Instamedi, a fictional health tech company that builds portal for patients and doctors for its group of hospitals, has decided to move it’s applications from a traditional hypervisor platform to Red Hat OpenShift Virtualization. This enables them to have a platform that addresses their current needs while also preparing them for future modernization and change all while enhancing the operational efficiency. Red Hat OpenShift Virtualization offers a compelling solution by allowing organizations to run both virtual machines (VMs) and containers on a single, unified platform. By migrating virtual machines from other platforms and running them on Red Hat OpenShift, they could get the most from their existing virtualization investments while taking advantage of cloud-native architectures, streamlined operations and management, and new development approaches.
To ensure a smooth transition from traditional hypervisors like VMware vSphere to Red Hat OpenShift Virtualization, Instamedi must adopt a phased migration strategy that minimizes downtime and disruption to its healthcare services. Given the critical nature of patient and doctor portals, maintaining uninterrupted access is essential. The traffic switchover from the services in the existing hypervisor to OpenShift Virtualization will be handled carefully to ensure zero downtime. This involves gradually redirecting traffic to services running on OpenShift virtualization while maintaining connectivity to the original VMs until the full migration is complete. Additionally, Instamedi aims to reduce the complexity involved in building and managing complex networking systems. By doing so, Instamedi can mitigate risks, maintain service continuity, and avoid disruptions to daily operations, all while efficiently transitioning to a more modern and scalable infrastructure.
3. The Solution
Instamedi decided to use implement Red Hat Service Interconnect as a key component of its migration strategy to simplify connectivity across its diverse environments. By leveraging the advanced Layer 7 addressing and routing capabilities of Service Interconnect, Instamedi ensured seamless communication between its applications during and after the migration process. This solution allowed their applications to communicate effortlessly across both the traditional hypervisor platform and OpenShift Virtualization, even as components were gradually moved or updated. Service Interconnect’s anycast and multicast capabilities, enabled multiple instances of a service deployed in different destinations to use the same service address. This streamlined routing of requests to instances of a single service, regardless of whether they were running - original hypervisor or OpenShift Virtualization. If a VM is disconnected or a service is undeployed post-migration, traffic is automatically and seamlessly switched over to newly migrated service instances that are using the same address, ensuring continuous operation without disruption.