How this works
- Drag components from the left onto the canvas.
- Drag from the dot on one box's right edge to the dot on another's left to connect them. One box can feed several — a load balancer across three app servers splits the traffic between them.
- Click a box to set instances and zones, or a line to set what it carries.
- Delete anything by selecting it and pressing Backspace.
- Move the traffic slider and watch utilization change live.
- Run the pressure test when you think it will hold.
Start from the Users node — traffic enters there.
Lines are request arrows and the response comes back along them, so you never draw one back the other way. For a database taking reads and writes from one server, a single line carrying both is right.