Rancher Labs today announced the general availability of Longhorn, which provides Kubernetes clusters with access to block storage to enable IT organizations to deploy distributed stateful applications.
Longhorn is open source software originally developed by Rancher Labs that is now a sandbox project being developed under the auspices of the Cloud Native Computing Foundation (CNCF).
Rancher Labs CEO Sheng Liang says the company is now providing commercial support for Longhorn to its customers that employ the distribution of Kubernetes curated by Rancher Labs.
Longhorn is designed to make it possible to add persistent storage via a single click to a Kubernetes cluster. In addition, it provides snapshot and backup and restore capabilities, including support for recovery time and point objectives between clusters. IT teams can also schedule asynchronous replication between instances of Longhorn.
Other capabilities include support for thin provisioning, non-disruptive volume expansion, access to a standalone user interface alongside command-line interface (CLI) integration with Kubernetes and support for live Longhorn upgrades.
Collectively, those built-in capabilities will make the total cost of storage on a Kubernetes cluster less expensive than it is on most legacy storage platforms.
Based on 30,000 lines of Go code, Longhorn is significantly lighter than traditional storage software because it builds on existing Linux storage primitives. Liang says as microservices-based software, Longhorn can be deployed anywhere to give each volume essentially its own micro-controller. As such, Longhorn can also serve as a bridge to integrate enterprise-grade storage with Kubernetes by enabling users to deploy Longhorn on existing NFS, iSCSI and Fibre Channel storage arrays or on cloud storage systems, he says.
Next up, Liang says he expects the Longhorn community to focus on tighter application-level integrations that would serve to make Longhorn more widely available.
As a Kubernetes adoption continues to grow, it’s clear the management of compute and storage will converge in the future. There may always be external storage resources that are managed by a dedicated storage administrator, given the sheer volume of data that needs to be managed within an IT environment. However, access to primary data storage is more likely to be managed as part of the Kubernetes cluster. As a result, management of storage cloud-native computing environments based on Kubernetes may about to become a lot more federated than it is in many monolithic application environments, which still depend on rack servers to access storage arrays.
In the meantime, as the number of stateful enterprise-class applications being developed using containers continues to rise, the need for an efficient means of accessing data stored on a Kubernetes cluster is becoming more pressing. A survey published earlier this year by the CNCF found of 14% of respondents are using storage projects in production, with another 27% evaluating storage projects. It may be early days as far as Kubernetes storage is concerned, but as Longhorn continues to evolve as a CNCF project it is apparent when it comes to persistent storage what direction many members of the Kubernetes community are headed.