Terminology¶

vPoller Proxy: ZeroMQ proxy which distributes tasks and load balances client requests. The application running the vPoller Proxy is vpoller-proxy.
vPoller Worker: Worker application which processes tasks, such as discovery and polling of vSphere object properties. The vPoller Worker receives new tasks for processing from the backend endpoint of a vPoller Proxy. The application running the vPoller Worker is vpoller-worker.
vPoller Client: Client application used for sending task requests and receiving of results. The vPoller Client sends task requests to the frontend endpoint of a vPoller Proxy. The application running the vPoller Client is vpoller-client and vpoller-cclient, which is the client application written in C.
vSphere Agent: The vSphere Agents are the ones that take care of establishing connections to the vSphere hosts and perform discovery and polling of vSphere objects. The vSphere Agents are running on the vPoller Workers and a single vPoller Worker can have as many vSphere Agents as you’d like. vSphere Agents are configured and managed by the vconnector-cli tool.

On the image below you can see how each vPoller component relates to the others.

Here is what happens when you send a client task request:

A vPoller Client sends a task request to the frontend endpoint of a vPoller Proxy.
Task request is received on the vPoller Proxy and is dispatched to any connected vPoller Workers on the backend endpoint.
The task request is received on the vPoller Worker and given to a vSphere Agent which is taking care of the requested vSphere host for processing the request through the VMware vSphere API.
The vSphere Agent returns any result from the operation to the vPoller Worker which in turn sends the result through the vPoller Proxy back to the client which requested the task.