Difference between UiPath multi-node architecture and high availability setup.
Multi Node High Availability
High availability (HA) provides redundancy and stability for the multi-node Orchestrator deployment by ensuring that multiple Orchestrator and HAA nodes are available. When one node fails, the other nodes can automatically take over the workload, minimizing downtime and ensuring continuous operation.
Additionally, HA deployment also offers horizontal scalability, which means you can add more Orchestrator and HAA nodes as needed to handle increased workload and manage growing Robot requirements.
Overall, an HA deployment provides a robust and reliable solution for running a UiPath Orchestrator in a multi-node environment, with automatic failover, redundancy, and scalability to handle varying workloads.
Details of the high availability architecture and all components required required to work, are explained below.
High Availability Add-On
The high availability add-on (HAA) is a component of UiPath Orchestrator that provides high-availability and disaster recovery capabilities for Orchestrator installations. This HA add-on is available in a Linux Redis Cluster with three or more nodes. It's responsibility is to make sure all the transactions and their information are synchronized between all the Orchestrator nodes. In the event where one of the UiPath Orchestrator Windows IIS servers goes down, the other two would be to pick all the transactions that were being processed by the missing node and continue their process.
In a set up of three Redis HA nodes, there will be one always communicating with the three Windows IIS servers. Whereas the other two, their Redis nodes would wait in standby mode.
Below is the image of Redis:
Key Differences
- Purpose: Multi-node architecture primarily focuses on scalability and workload distribution, while high availability setup focuses on ensuring continuous operation and minimizing downtime.
- Implementation: Multi-node architecture involves deploying multiple instances of UiPath Orchestrator across different nodes, while high availability setup involves introducing redundancy and failover mechanisms to ensure continuous operation.
- Scalability vs. Resilience: Multi-node architecture primarily addresses scalability concerns by distributing workload, whereas high availability setup primarily addresses resilience concerns by ensuring continuous operation in the face of failures.
- Resource Utilization: Multi-node architecture can help balance resource utilization across multiple servers, while high availability setup introduces redundancy which may result in slightly higher resource usage.
In summary, while both approaches aim to enhance the performance and reliability of UiPath Orchestrator, they do so in different ways and serve different objectives. Multi-node architecture focuses on scalability, while high availability setup focuses on ensuring continuous operation and minimizing downtime.