If your deployment has grown and you need to increase capacity, expanding your Orchestrator to a multi-node installation is the next logical step. It offers both better performance and failure resistance as multiple Orchestrator nodes are available - when one fails, the other(s) can pick up the load. Horizontal scalability is also available, as it is possible to add additional nodes as your Robot needs grow further. This deployment model should not, however, be confused with High Availability, as the lone HAA node remains as a potential single point of failure.
Remember to take into consideration the Orchestrator hardware requirements corresponding to the scale of your deployment.
Please note that this model is more resource intensive than a single node installation, requiring additional components such as the High Availability add-on for Orchestrator (or other tested solution) and a network load balancer.
The diagram below depicts a simple multi-node deployment of two or more Orchestrator nodes synchronized using a single HAA node:
Multi-node Orchestrator deployments are supported by UiPath only if the UiPath High Availability Add-on is used.
Such deployments use the RESP (REdis Serialization Protocol) for communication, and thus can be configured using any solution implementing this protocol. The potential solutions tested (but not supported) by UiPath are:
MSOpenTech Redis on Windows v3.0.504
Redis Server v3.2.8 and v5.0.4
Redis Enterprise v5.4.0-19
Updated about a year ago