ClusterLabs

ClusterLabs
Name	ClusterLabs
Founded	2000s
Type	Non-profit project
Focus	High-availability clustering software
Headquarters	Distributed
Products	Pacemaker, Corosync, crmsh

ClusterLabs is an open-source software project that develops high-availability clustering tools and related infrastructure for distributed computing. The project is best known for producing clustering components used in enterprise and research deployments, integrating with operating systems, virtualization platforms, and storage solutions. ClusterLabs technologies are used in production by organizations running critical services on Linux, interacting with vendors, standards bodies, and upstream projects.

History

ClusterLabs emerged in the early 2000s amid increased demand for fault-tolerant services in Internet infrastructure and enterprise datacenters. Early contributors included participants from Linux distributions and vendors who had worked on clustering in projects such as Red Hat, SUSE, Debian, Oracle Corporation technical teams, and academic institutions. The project evolved alongside contemporaneous efforts like High Availability Linux Project and interoperated with cluster messaging systems developed in the same era, including work influenced by research from University of California, Berkeley and engineering at Sun Microsystems. Over time, ClusterLabs attracted developers familiar with Linux kernel internals, storage systems from NetApp and EMC Corporation, and virtualization initiatives from Xen Project and KVM. Major milestones include the initial releases of core components, adoption in production by telecommunications firms, and integration into configuration management and orchestration ecosystems led by teams at Canonical and Red Hat Enterprise Linux.

Projects and Components

The project maintains several primary components focused on cluster membership, resource management, and administration. The most widely deployed component, Pacemaker, acts as a resource manager compatible with resource agents from standards like the Open Cluster Framework and integrates with fencing mechanisms originating from projects such as STONITH implementations by various vendors. Corosync provides messaging and membership services and traces conceptual lineage to designs used in OpenSSI and research at Lawrence Livermore National Laboratory. Additional tooling includes crmsh for shell administration, cluster resource agents developed against LSB init scripts and systemd service models, and integration adapters for orchestration tools from Ansible, Puppet, and Chef. The component ecosystem also contains modules that interact with storage clusters such as Ceph and networked file systems like NFS and GlusterFS.

Architecture and Features

The architecture separates cluster communication, membership, quorum, fencing, and policy-based resource management into modular layers. Corosync handles reliable multicast and membership events using protocols influenced by academic literature and operational designs used at Google and Yahoo! for distributed coordination. Pacemaker implements policy-driven placement, constraints, and resource dependency graphs similar to scheduler logic found in projects like Apache Mesos and orchestration patterns from Kubernetes (control-plane concepts), while remaining focused on high-availability semantics rather than container orchestration. Fencing (STONITH) integrations ensure split-brain prevention through hardware interfaces from Dell EMC iLO, HPE iLO, and cloud control planes such as those provided by Amazon Web Services and Microsoft Azure. Features include cluster constraints, location and order rules, failover domains, resource monitoring, and maintenance modes. Administrative interfaces span command-line tooling compatible with Bash environments, monitoring hooks for Prometheus exporters, and logging suited for aggregation by systems like ELK Stack.

Use Cases and Deployments

ClusterLabs components are used across telecommunications, finance, scientific computing, and cloud infrastructure. Typical deployments include active/passive failover for databases such as PostgreSQL and MySQL, active/active resource sets for application servers operated by enterprises like Bank of America-scale deployments, and controller clusters for storage backends in environments using Ceph and GlusterFS. Research facilities running workloads managed by Slurm Workload Manager and HPC centers have leveraged high-availability control planes from ClusterLabs to protect metadata services. Integrations exist with virtualization managers like oVirt and hypervisor stacks from the Xen Project, and operators combine ClusterLabs with configuration management from SaltStack or orchestration via OpenStack projects to provide resilient control services.

Governance and Community

The governance model is meritocratic and community-driven, with contributors from multiple corporations, independent contractors, and academic projects collaborating via mailing lists, code repositories, and public issue trackers hosted on platforms analogous to GitHub and GitLab. Technical steering and release decisions result from consensus among active maintainers, contributors from vendor teams (including engineers from SUSE and Red Hat), and operators from service providers. The community engages in interoperability tests at events similar to LinuxCon and participates in standards discussions alongside organizations like the Linux Foundation. Documentation and tutorials are contributed by ecosystem partners, open-source advocates, and academic authors who publish case studies in conference proceedings.

Licensing and Distribution

ClusterLabs software is released under permissive free-software licences compatible with major distributions; components have historically used licences such as the GNU General Public License and other FLOSS-compatible licences to enable inclusion in distributions maintained by Debian Project, Fedora Project, and openSUSE. Binary packages and source are distributed through distribution repositories, vendor channels, and upstream project archives, allowing integration into enterprise products certified by vendors like Red Hat and appliance offerings from storage and networking companies. Third-party vendors and cloud providers ship and support builds in compliance with these licences to enable commercial support and long-term maintenance.

Category:High-availability software