Part 3 - How Zerto’s One-to-Many Supports Kubernetes - Zerto
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Part 3 – How Zerto’s One-to-Many Supports Kubernetes

April 13, 2023
Zerto Solution
Est. Reading Time: 5 minutes

The first post in this series introduced Zerto’s one-to-many replication functionality. The second post discussed one-to-many replication in detail and provided three common use case scenarios. In this post, we start by discussing the threats against applications running as Kubernetes clusters. This post deals with how Zerto’s one-to-many replication supports Kubernetes.

We’ll cover the threats against applications running as Kubernetes clusters and how Zerto for Kubernetes and its one-to-many replication functionality protects against them. We’ll also look at two common use cases of the technology.

Problems Plaguing Kubernetes Clusters

Kubernetes is a popular platform for building and deploying applications. But like any system, it can be subject to unplanned disruptions. These disruptions range from minor inconveniences to major outages and can have a significant impact on the availability and performance of your applications.

The following are the top five common unplanned disruptions that can occur when building applications on Kubernetes:

  • Node failures: Nodes are the physical or virtual machines that run your applications. They’re managed by the Kubernetes control plane. If a node fails, the applications running on that node will be impacted and may become unavailable. Kubernetes has built-in mechanisms for handling node failures, but if these mechanisms do not work as expected, disruptions will occur.
  • Network issues: Network issues occur at various levels, from local networking problems on a node to issues with external networks. These issues can prevent communication between nodes and lead to disruptions in application availability and performance.
  • Resource constraints: Kubernetes allows for specific resource requirements for your applications, such as CPU and memory. However, if these resources are not properly configured, applications may experience resource constraints, leading to poor performance or even failures.
  • Configuration errors: Kubernetes allows users to configure a wide range of settings for their applications, such as environment variables and command-line arguments. If these settings are not configured correctly, applications may not work as expected, leading to disruptions.
  • Security vulnerabilities: Kubernetes is a complex system with many components and dependencies. As such, it is vulnerable to security threats, such as network attacks, malware, and data breaches. These vulnerabilities can lead to disruptions in application availability and performance, as well as data loss or theft.

Mitigating these unplanned disruptions requires a combination of careful planning, proactive monitoring, and a quick response to issues as they arise. It is important to update your Kubernetes clusters with the latest security patches and to have a disaster recovery plan in place. Additionally, monitoring Kubernetes clusters and applications can provide early warning signs of potential issues, giving you a chance to act before they become disruptions.

Zerto for Kubernetes and One-to-Many Replication

Zerto for Kubernetes provides disaster recovery and mobility for containerized applications in a simple, scalable solution. It uses a journal to track and replicate stateful data, which are stored on persistent volumes (PVs), StatefulSets, Deployments, Services, ConfigMaps, Secrets, PV Claims, and ingress controllers.

Zerto for Kubernetes’s one-to-many replication functionality enables data replication from a single source cluster to multiple Kubernetes platforms. Users leverage Zerto’s near-synchronous replication to protect important resources in their Kubernetes clusters from data loss and downtime or migrate them elsewhere. In the event of a disaster, users can restore the application across multiple on-premises clusters or Kubernetes services running in the public cloud.

How It Works

Zerto for Kubernetes can protect the same entity in a Kubernetes cluster multiple times. The Zerto for Kubernetes Manager Proxy (ZKM-PX) and virtual replication application (VRA) accomplish this by installing on worker nodes in the target clusters. Virtual protection group (VPG) names are then added to the annotation fields of the resource being protected. The recommended configuration is to replicate no more than three VPGs, both inbound and outbound. Although you can exceed this configuration, performance degradation may appear if pod/cluster resources are being overutilized.

Use Cases

Disaster Recovery and Multi-Cloud Mobility

If a disruption takes a primary site offline, Zerto for Kubernetes’s one-to-many replication functionality can bring the application online seamlessly at another location by performing live failovers to multiple target sites. Zerto for Kubernetes allows for this near real-time replication and recovery of Kubernetes applications to occur between two or more sites. Once you validate that the application is running correctly at the desired point of recovery on another site, you can commit the newly replicated Kubernetes resources to production.

Strong security practices demand the frequent testing of disaster recovery solutions as well. The Zerto for Kubernetes Failover Test workflow can help users test the failover operations to multiple target sites. Users can bring an application up on a second or third cluster in an isolated namespace while the production version of the application continues to run unaffected.

Finally, Zerto achieves multi-cloud mobility by using the “move” operation to migrate from one Kubernetes service to multiple target clusters—whether on-premises or in the public cloud. In leveraging one-to-many replication, users can migrate to multiple clusters quickly and efficiently, reducing the time and resources required to re-create the application manually.

Zerto for Kubernetes Mitigates Disruptions

Kubernetes is a powerful platform for building and deploying applications, but it is not immune to unplanned disruptions. These challenges can range from minor inconveniences to major outages with a significant impact on the availability and performance of your applications. Deploying Zerto for Kubernetes helps prevent and mitigate these disruptions. Zerto for Kubernetes’s one-to-many replication functionality enables data replication from a single source cluster to multiple Kubernetes platforms.

Users leverage Zerto’s near-synchronous replication to protect or migrate important resources in their Kubernetes clusters from data loss and downtime. In the event of a disaster, users can restore the application across multiple on-premises clusters or Kubernetes services running in the public cloud. In the event of a disaster or when migrating to multiple Kubernetes clusters, one-to-many replication empowers users with the ability to flexibly recover and scale their Kubernetes applications.

 

The next and final part of our miniseries is going to cover how Zerto can protect and migrate on-premises VMs to AWS EC2 instances.

Anthony Dutra

Anthony Dutra is a Technical Marketing Manager (TME) at Zerto, a Hewlett Packard Company who specializes in solution architecture, designing microservices in the public cloud, and developing web3 (blockchain) applications. For the past decade, Anthony has leveraged his Master’s in IT Management to become a trusted technical partner with organizations seeking to modernize their data center or migrate to the cloud.