Work with Nodes
What Is a Node?
Nodes are the devices (servers or virtual servers) that make up your Hero_Flow environment (cluster). Hero_Flow's gossip protocol allows each node encrypted communication with other sets of nodes allowing for the quick spread of information and scaling. This system maintains resiliency by operating without a centralized master entity and overcomes network issues and node failures. It is possible, therefore, to use nodes located on Google Cloud, Amazon Web Services, in a datacenter, or where ever your servers are located at the same time. This provides more flexibility than using a central entity.
How to Work with a Node?
When setting up your environment in Hero_Cloud, you can select the size environment you want to create based on your process needs.
A drop-down list is displayed to select the size environment that fits your needs. Each environment is made up of a UI node and additional compute/processing nodes.
The number of nodes that is selected during the setup process are displayed on Hero_Flow's Node overview page.
Nodes Overview Page
View the Nodes overview page by clicking Nodes in the menu.
Use the Nodes overview page to monitor traffic in the cluster. Displayed are active nodes, memory, CPU status, and the associated roles.
Nodes pull elements from the upstream, process those elements, and then push them downstream.
- Pull latency- The time difference between a node asking for a new element from the upstream and the node getting that element.
- Push latency - The time difference between the node pushing the element to the downstream and the element being accepted by the downstream.
- Backpressure - How many elements in the upstream are currently waiting in a queue to be processed by the node.
The Node roles are displayed on the right side of the screen. Each Node has 1 or more roles assigned to it.
For example, if you have a single machine, it would have all the roles you need running. When you have multiple Nodes, these roles are distributed over the group. Roles are automatically assigned to the Nodes.
|frontend||This role indicates the node that runs the Hero_Flow user interface.|
Used to do computations–there can be one or more nodes with this role.
Flows cannot run without this role.
|dc_default||Default data center|