Junos Space High Availability Overview
Junos Space is designed as a carrier-grade system that provides a complete fault tolerant solution. The set of topics describing Junos Space high availability (HA) provide an overview of the Junos Space high availability design and implementation, as well as all the steps that are required to deploy a high availability solution, from ordering your appliances and preparing a Junos Space high availability cluster, to final deployment.
In order to gain an understanding of the Junos Space high availability solution, we recommend that you read all the Junos Space high availability topics. However, if you are primarily interested in setting up high availability, including the prerequisite steps, see the Configuring the Junos Space Cluster for High Availability Overview topic. If you are interested in high availability for network monitoring, see High Availability for Network Monitoring. A set of frequently asked questions about Junos Space high availability are also answered in FAQ: Junos Space High Availability.
Junos Space Network Management Platform is available in two form factors:
JA2500 carrier-grade hardware appliance
Virtual appliance for the VMware ESX server or Kernel-based Virtual Machine (KVM) environment
Both the Junos Space hardware appliance and virtual appliance use the same software build with identical features to provide the complete package including OS, databases, load balancers and JBoss engines. You can cluster multiple appliances together to form a Junos Space cluster, as shown in Figure 1.
A Junos Space fabric (cluster) can contain only hardware appliances (JA2500), only virtual appliances, or a combination of both hardware and virtual appliances. Each appliance in the cluster is called a node. Junos Space cluster architecture also incorporates load balancing across all nodes in the cluster, which becomes the basis for providing scalability for a Junos Space deployment.
A Junos Space high availability solution comprises the following key components:
Junos Space cluster architecture allows multiple Junos Space appliances (hardware or virtual) to be connected together to form a single cluster. All services within the cluster are provided through a single virtual IP address that GUI and Northbound Interface (NBI) clients can use. This architecture provides protection against any single point of failure (SPOF) in the cluster. If any node in the cluster fails, all services continue to be available, albeit with reduced capacity.
Four logical clusters can be formed within the single physical cluster when Junos Space appliances are connected together. For more information, see Understanding the Logical Clusters Within a Junos Space Cluster.
The Junos Space Appliance (JA2500) is a carrier-grade hardware appliance designed to ensure hardware-level reliability and incorporates several fault tolerance features to eliminate single point of failure and minimize its downtime. The Junos Space Appliance contributes significantly to the availability of the overall cluster. For more information, see the High Availability Characteristics of Junos Space Appliances topic.
The Watchdog service provides process-level high availability. In the event of any software services failure on a Junos Space appliance, the watchdog service automatically restarts the service.