Integration
E2SAR uses a combination of UDP packets and gRPC+TLS to communicate with loadbalancer control plane and dataplane.
All interactions are captured in the figure below.
The process of using the load balancer begins with (1) reserving a load balancer using an out-of-band information like the admin token and the ejfat URL of the Control Plane agent. This can be done by one of the receivers or by Workflow Management System (WMS) or its proxy.
Once the load balancer is reserved and the details of the reservation communicated out of band (shown with dotted lines) to the worker nodes, they can register themselves with the control plane (2). Alternatively the registration can be peformed by WMS or its proxy assuming the details of the workers are known to it.
At this point (after all workers have been registered and the details of the load balancer communicated to the sender(s) - shown with dotted lines) data can begin traversing the dataplane in segments (3a and 3b).
Periodic sync messages (4) are required to be sent by the sender once a second. Similarly the receiving nodes or WMS on their behalf must periodically use SendState gRPC call (5) to update queue occupancy information in the control plane.
After the workflow completes, the workers can be deregistered (6) - themselves or via WMS. The load balancer can be freed (7).
Additional details are contained in this document