High Availability Clustering (Legacy)

High Availability Clustering is a legacy feature that only works on the Orient database.

All new deployments should use one of our new high availability NEW IN 3.50.0 or resilient deployment options described in Resiliency and High Availability.

Only available in Nexus Repository Pro. Interested in a free trial? Start here.

Overview

Legacy High Availability Clustering (HA-C) is a feature designed to improve uptime by having a cluster of redundant Nexus Repository "nodes" (instances) within a single data center. This feature allows you to maintain availability to your Nexus Repository in the event one of the nodes becomes unavailable.  A typical Nexus Repository HA-C cluster is shown below:

HA-C cluster comprising three nodes with inter-node replication.

Software and Hardware Requirements

Here’s a list of the most important things you will need:

  • A test environment to evaluate your cluster configuration and processes
  • Nexus Repository Manager Professional license and the latest version
  • A load balancer, such as NGINX or Apache HTTP or AWS ELB
  • 3 separate instances of Nexus Repository installed on 3 different systems (e.g., 3 different EC2 instances) in a single datacenter
  • Network connectivity between the 3 different systems so the Nexus Repository can communicate with each other on several ports
  • Separate local and shared storage (the difference will be described below)
  • Each node needs to be configured according to our general requirements.

In addition to these items, this guide will clarify the key concepts of Node, Blob Store, and Hazelcast and outline the operational considerations specific to HA-C.

Known Issues and Limitations

  • HA-C is not desgined for dynamic orchestration, as such deployment to environments such as Kubernetes or OpenShift is not supported.
  • The initial functionality intends to support a three-node cluster in a single datacenter. Cross-datacenter (WAN) replication is not supported at this time.  For AWS, all nodes must be in the same availability zone.
  • Upgrading an already established cluster to a new version of Nexus Repository requires shutting down all nodes. Support for rolling upgrades is not yet available.

Format Limitations

  • HA-C supports the following formats: Bower, Docker, Git LFS, Maven, npm, NuGet, PyPI, Raw, Rubygems, and Yum.
  • Apt, Cocoapods, Conan, Conda, Go, Helm, p2, and R formats are currently disabled.

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