def test_api_cg_creation_dsa():
# creating a computation graph from API, without relying on a full
# description of the DCOP.
# Two API level
# * DCOP : create a dcop
# * Computation graph:
# DCOP
# works when using an orchestrator that can transform a dcop into a
# computation graph and distribute the computation on the set of agents.
# Efficient and simple solution when there is a single deployement of the
# system at startup.
# Computation Graph
# create the computations directly
# Necessary when there is no central place where the full dcop could be
# created. Each agent build the computation it will run, for example when
# the definition of the dcop changes at run time or when a new dcop must be
# created and solve completely dynamically and runtime without relying on a
# central element like an orchestrator.
# to create a computation instance, one need:
# of course, variable(s) and constraint(s) like for the dcop.
# but also
# an algo_def : given as input
# a comp_node : depends of the type of computation graph, requires a
# variable and or constraints
# Here we define a simple graph coloring problem with 3 variables:
d = Domain('color', '', ['R', 'G'])
v1 = Variable('v1', d)
v2 = Variable('v2', d)
v3 = Variable('v3', d)
# We need to define all agents first, because we will need their address
# when registering neighbors computation
agt1 = Agent('a1', InProcessCommunicationLayer())
agt2 = Agent('a2', InProcessCommunicationLayer())
agt3 = Agent('a3', InProcessCommunicationLayer())
# Agent 1 with Variable v1
# Constraints in which v1 is involved
cost_v1 = constraint_from_str('cv1', '-0.1 if v1 == "R" else 0.1 ', [v1])
diff_v1_v2 = constraint_from_str('c1', '1 if v1 == v2 else 0', [v1, v2])
# Computation node for the variable with these constraints
node_v1 = chg.VariableComputationNode(v1, [cost_v1, diff_v1_v2])
comp_def = ComputationDef(node_v1, AlgorithmDef.build_with_default_param('dsa'))
v1_computation = build_computation(comp_def)
# and register the computation and the agents for the neighboring
# computations.
agt1.add_computation(v1_computation)
agt1.discovery.register_computation('v2', 'a2', agt2.address)
# Agent 2 with Variable v2
cost_v2 = constraint_from_str('cv2', '-0.1 if v2 == "G" else 0.1 ', [v2])
diff_v2_v3 = constraint_from_str('c2', '1 if v2 == v3 else 0', [v2, v3])
node_v2 = chg.VariableComputationNode(v2, [cost_v2, diff_v2_v3, diff_v1_v2])
comp_def_v2 = ComputationDef(node_v2,
AlgorithmDef.build_with_default_param('dsa'))
v2_computation = build_computation(comp_def_v2)
agt2.add_computation(v2_computation)
agt2.discovery.register_computation('v1', 'a1', agt1.address)
agt2.discovery.register_computation('v3', 'a3', agt3.address)
# Agent 3 with Variable v3
cost_v3 = constraint_from_str('cv3', '-0.1 if v3 == "G" else 0.1 ', [v3])
node_v3 = chg.VariableComputationNode(v3, [cost_v3, diff_v2_v3])
comp_def_v3 = ComputationDef(node_v3,
AlgorithmDef.build_with_default_param('dsa'))
v3_computation = build_computation(comp_def_v3)
agt3.add_computation(v3_computation)
agt3.discovery.register_computation('v2', 'a2', agt2.address)
# Start and run the 3 agents manually:
agts = [agt1, agt2, agt3]
for a in agts:
a.start()
for a in agts:
a.run()
sleep(1) # let the system run for 1 second
for a in agts:
a.stop()
# As we do not have an ochestrator, we need to collect results manually:
assert agt1.computation('v1').current_value != \
agt2.computation('v2').current_value
assert agt3.computation('v3').current_value != \
agt2.computation('v2').current_value
def test_api_cg_creation_mgm2():
# This time we solve the same graph coloring problem with the MGM2
# algorithm.
# As you can see, the only difference is the creation of the AlgorithmDef
# instance with 'mgm2'
d = Domain('color', '', ['R', 'G'])
v1 = Variable('v1', d)
v2 = Variable('v2', d)
v3 = Variable('v3', d)
# We need to define all agents first, because we will need their address
# when registering neighbors computation
agt1 = Agent('a1', InProcessCommunicationLayer())
agt2 = Agent('a2', InProcessCommunicationLayer())
agt3 = Agent('a3', InProcessCommunicationLayer())
# Agent 1 with Variable v1
cost_v1 = constraint_from_str('cv1', '-0.1 if v1 == "R" else 0.1 ', [v1])
diff_v1_v2 = constraint_from_str('c1', '1 if v1 == v2 else 0', [v1, v2])
node_v1 = chg.VariableComputationNode(v1, [cost_v1, diff_v1_v2])
comp_def = ComputationDef(node_v1,
AlgorithmDef.build_with_default_param('mgm2'))
v1_computation = build_computation(comp_def)
agt1.add_computation(v1_computation)
# We need to register manually as we are not using the directory hosted by
# the orchestrator.
agt1.discovery.register_computation('v2', 'a2', agt2.address)
# Agent 2 with Variable v2
cost_v2 = constraint_from_str('cv2', '-0.1 if v2 == "G" else 0.1 ', [v2])
diff_v2_v3 = constraint_from_str('c2', '1 if v2 == v3 else 0', [v2, v3])
node_v2 = chg.VariableComputationNode(v2, [cost_v2, diff_v2_v3, diff_v1_v2])
comp_def_v2 = ComputationDef(node_v2,
AlgorithmDef.build_with_default_param('mgm2'))
v2_computation = build_computation(comp_def_v2)
agt2.add_computation(v2_computation)
agt2.discovery.register_computation('v1', 'a1', agt1.address)
agt2.discovery.register_computation('v3', 'a3', agt3.address)
# Agent 3 with Variable v3
cost_v3 = constraint_from_str('cv3', '-0.1 if v3 == "G" else 0.1 ', [v3])
node_v3 = chg.VariableComputationNode(v3, [cost_v3, diff_v2_v3])
comp_def_v3 = ComputationDef(node_v3,
AlgorithmDef.build_with_default_param('mgm2'))
v3_computation = build_computation(comp_def_v3)
agt3.add_computation(v3_computation)
agt3.discovery.register_computation('v2', 'a2', agt2.address)
# Start and run the 3 agents manually:
agts = [agt1, agt2, agt3]
for a in agts:
a.start()
for a in agts:
a.run()
sleep(1) # let the system run for 1 second
for a in agts:
a.stop()
# As we do not have an orchestrator, we need to collect results manually.
# As with MGM, MGM2 does not necessarily find the optimal solution,
# depending on the start affectation (which may require a 3-coordinated
# change and thus is not possible with mgm2), so we just check the
# hard constraints
assert agt1.computation('v1').current_value != \
agt2.computation('v2').current_value
assert agt3.computation('v3').current_value != \
agt2.computation('v2').current_value