A grid is a group of flood agents running on any type of computer (for example a laptop or a cloud-managed VM instance).
Agents with the same name are part of the same grid
If you're working on a single machine (your laptop for example) you can let flood-agent pick a random name like submerged-dolphin.
Say you'd like to run a larger grid. You could run flood-agent on a second machine
flood-agent --grid submerged-dolphin
However, in this case it'd just be easier to start both agents with a grid name of your choosing:
# ec2 instance 1
aws-ec2-1 $ ./flood-agent --name aws-grid-1
# ec2 instance 2
aws-ec2-2 $ ./flood-agent --name aws-grid-1
Machines running in the same Grid should be homogeneous (though it isn't mandatory)
For example, using a laptop on home a broadband connection and an extra-large VM instance located in a cloud provider's datacenter as part of the same grid would make test results difficult to interpret and trust.
A flood is an instance of a load test plan. To run a load test, a flood is scheduled onto one or more grids.
So, when you run a flood, it ends up running on all the flood-agent instances running within the grids you have organised and selected:
To run a load test, define a flood with the Stream Editor. As the last step, decide on which grids your test should run. Once you hit "Launch" flood.io ensures your load test runs on the correct machines.
A "node" runs two main processes flood-agent and a load generator.