Simple DFD example

dfd.dot

strict digraph 8320840571571852364 {
	graph [
		label="My WebApp"
		fontname="Arial"
		fontsize="14"
		labelloc="t"
		fontsize="20"
		nodesep="1"
		rankdir="t"
	];
	node [
		fontname="Arial"
		fontsize="14"
	];
	edge [
		shape="none"
		fontname="Arial"
		fontsize="12"
	];

	subgraph cluster_3099958727017326363 {
		graph [
			label="External Network"
			fontsize="10"
			style="dashed"
			color="grey35"
			fontcolor="grey35"
		];

		// Node definitions.
		process_3677006010347689991 [
			label="Client"
			shape=circle
		];
	}
	subgraph cluster_3862918028289041540 {
		graph [
			label="Amazon AWS West"
			fontsize="10"
			style="dashed"
			color="grey35"
			fontcolor="grey35"
		];

		// Node definitions.
		datastore_5357599094606810278 [
			label="sqlite"
			shape=cylinder
		];
		datastore_8084409724099743465 [
			label="Logs"
			shape=cylinder
		];
		process_8758260597333559320 [
			label="Web Server"
			shape=circle
		];
	}
	// Node definitions.
	process_3677006010347689991 [
		label="Client"
		shape=circle
	];
	externalservice_4332697472613199435 [
		label="Google Analytics"
		shape=diamond
	];
	datastore_5357599094606810278 [
		label="sqlite"
		shape=cylinder
	];
	datastore_8084409724099743465 [
		label="Logs"
		shape=cylinder
	];
	process_8758260597333559320 [
		label="Web Server"
		shape=circle
	];

	// Edge definitions.
	process_3677006010347689991 -> externalservice_4332697472613199435 [label=<<table border="0" cellborder="0" cellpadding="2"><tr><td><b>HTTPS</b></td></tr></table>>];
	process_3677006010347689991 -> process_8758260597333559320 [label=<<table border="0" cellborder="0" cellpadding="2"><tr><td><b>HTTPS</b></td></tr></table>>];
	process_8758260597333559320 -> datastore_5357599094606810278 [label=<<table border="0" cellborder="0" cellpadding="2"><tr><td><b>HTTP</b></td></tr></table>>];
	process_8758260597333559320 -> datastore_8084409724099743465 [label=<<table border="0" cellborder="0" cellpadding="2"><tr><td><b>TCP</b></td></tr></table>>];
}