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When IT administrators deploy containers across various environments, including cloud and the edge, it can lead to container sprawl. Sprawl complicates tracking and managing containers, and it can harm system performance and introduce security and governance issues. Admins can use virtual clusters to consolidate and minimize administrative efforts and avoid container sprawl.
Container sprawl isn't about the number of containers admins deploy, but rather how they deploy them. Many admins use Kubernetes to manage containers because it offers load balancing, service discovery, storage orchestration, automated rollouts and configuration management. But when admins spin up new Kubernetes clusters, they often do so without following a standardized approach.
Admins then implement those clusters across multiple locations; they can migrate containers can between systems that share the host OS type. As a result, clusters are more difficult to track and manage.
Understand container sprawl
Container sprawl can introduce a host of disadvantages, such as governance issues and administrative complexities. Container sprawl can also undermine system performance.
For example, admins might configure Kubernetes clusters differently or run conflicting software in each cluster, which can result in performance inconsistencies. Diagnosing and troubleshooting performance issues becomes more complex and time-consuming, making it difficult to address issues in a timely manner.
Inconsistencies can also lead to security and compliance risks. If Kubernetes clusters don't receive the latest software updates, they might be susceptible to potential threats. In addition, a lack of centralized control for clusters can increase compliance violations and weaken the corporate network, which puts personal information and sensitive corporate data at risk.
Incorrectly deploying Kubernetes clusters can also lead to additional costs. Creating a Kubernetes cluster involves work, such as managing nodes, pods and APIs, and requires physical resources to host the necessary components. If admins deploy clusters in multiple environments, it can lead to unnecessary redundancy and underutilized resources.
Use virtual clusters to avoid container sprawl
To avoid container sprawl, some admins turn to virtual clusters. Virtual clusters are isolated environments that run within a physical Kubernetes cluster, similar to how VMs run in a virtual system. Virtual clusters offer similar benefits of Kubernetes clusters and also reign in the costs and complexities that come with multiple deployments.
To use virtual clusters, admins must deploy virtual cluster software within a Kubernetes environment. The virtual cluster software extends the Kubernetes infrastructure and abstracts its core components to help deliver multiple virtual clusters to a single physical cluster, similar to how a hypervisor deploys multiple VMs on the same server.
By reducing the number of physical clusters, admins can consolidate and minimize administrative efforts, improve resource utilization, and remove redundant operations and services, all while standardizing the underlying cluster infrastructure. In addition, virtual clusters simplify the Kubernetes cluster deployment process and provide isolated environments to work with.
All these factors help better control performance, maintain security and compliance, and rein in costs. But virtual clusters are a relatively new technology and only a few offerings exist, including k3v, Loft and SIG Virtual Cluster.
Most suggested use cases include development and testing, cloud-native development and DevOps methodologies, as well as experimentation or proof of concept.
Using Kubernetes namespaces as an alternative to virtual clusters
Kubernetes namespaces also offer similar functionalities to virtual clusters. Namespaces divide cluster resources among multiple users and provide a scope for working with related Kubernetes objects. Admins can deploy multiple namespaces on the same physical cluster, which supports users spread across multiple teams or projects. Unfortunately, every container that runs in a given namespace must have its own memory limit and can't exceed that limit.