Participant and controlloop event handling

This commit includes handling for ControlLoopUpdate and ParticipantStatus events, respective handling in ControlLoopHandler and ParticipantHandler is covered.
ParticipantStateChange, ControlLoopStateChange and ParticipantHealthCheck events are not covered in this commit.
Underlying participant logic (to handle Policy-participant APIs, DCAE-participant APIs etc) will be taken care in upcoming commits.

Issue-ID: POLICY-2987
Signed-off-by: Sirisha_Manchikanti <sirisha.manchikanti@est.tech>
Change-Id: Iba18c565218d2304ec57ce5bc47ad8765386db95

23 files changed, 1287 insertions, 85 deletions

diff --git a/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/main/java/org/onap/policy/clamp/controlloop/participant/simulator/main/rest/RestController.java b/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/main/java/org/onap/policy/clamp/controlloop/participant/simulator/main/rest/RestController.java
index 120c52c26..444f37889 100644
--- a/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/main/java/org/onap/policy/clamp/controlloop/participant/simulator/main/rest/RestController.java
+++ b/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/main/java/org/onap/policy/clamp/controlloop/participant/simulator/main/rest/RestController.java
@@ -34,9 +34,7 @@ import javax.ws.rs.core.MediaType;
 import javax.ws.rs.core.Response.ResponseBuilder;
 import lombok.AccessLevel;
 import lombok.Getter;
-import lombok.NoArgsConstructor;
-import org.onap.policy.clamp.controlloop.common.exception.ControlLoopRuntimeException;
-import org.onap.policy.clamp.controlloop.participant.intermediary.parameters.ParticipantIntermediaryParameters;
+import org.onap.policy.clamp.controlloop.participant.simulator.simulation.SimulationHandler;
 import org.onap.policy.clamp.controlloop.participant.simulator.simulation.SimulationProvider;
 
 /**
@@ -56,7 +54,6 @@ import org.onap.policy.clamp.controlloop.participant.simulator.simulation.Simula
     tags = {@Tag(name = "participantsim", description = "Participant Simulator")},
     securityDefinition = @SecurityDefinition(basicAuthDefinitions = {@BasicAuthDefinition(key = "basicAuth")}))
 // @formatter:on
-@NoArgsConstructor
 public class RestController {
     public static final String APPLICATION_YAML = "application/yaml";
 
@@ -95,17 +92,14 @@ public class RestController {
     public static final String SERVER_ERROR_MESSAGE = "Internal Server Error";
     @Getter(AccessLevel.PROTECTED)
     // The provider for simulation requests
-    private static SimulationProvider simulationProvider;
+    private SimulationProvider simulationProvider;
+
 
     /**
-     * Create a participant simulation provider.
-     * @return
-     *
-     * @throws ControlLoopRuntimeException on errors creating the provider
+     * create a Rest Controller.
      */
-    public static void init(ParticipantIntermediaryParameters participantParameters)
-                     throws ControlLoopRuntimeException {
-        simulationProvider = new SimulationProvider(participantParameters);
+    public RestController() {
+        simulationProvider = SimulationHandler.getInstance().getSimulationProvider();
     }
 
     /**
diff --git a/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/main/java/org/onap/policy/clamp/controlloop/participant/simulator/main/startstop/ParticipantSimulatorActivator.java b/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/main/java/org/onap/policy/clamp/controlloop/participant/simulator/main/startstop/ParticipantSimulatorActivator.java
index 8658750f8..4daa0393f 100644
--- a/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/main/java/org/onap/policy/clamp/controlloop/participant/simulator/main/startstop/ParticipantSimulatorActivator.java
+++ b/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/main/java/org/onap/policy/clamp/controlloop/participant/simulator/main/startstop/ParticipantSimulatorActivator.java
@@ -53,6 +53,10 @@ public class ParticipantSimulatorActivator extends ServiceManagerContainer {
             () -> simulationHandler.set(new SimulationHandler(parameters)),
             () -> simulationHandler.get().close());
 
+        addAction("Simulation Providers",
+            () -> simulationHandler.get().startProviders(),
+            () -> simulationHandler.get().stopProviders());
+
         parameters.getRestServerParameters().setName(parameters.getName());
 
         addAction("REST server",
diff --git a/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/main/java/org/onap/policy/clamp/controlloop/participant/simulator/simulation/SimulationHandler.java b/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/main/java/org/onap/policy/clamp/controlloop/participant/simulator/simulation/SimulationHandler.java
index e409460c0..e6e2609da 100644
--- a/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/main/java/org/onap/policy/clamp/controlloop/participant/simulator/simulation/SimulationHandler.java
+++ b/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/main/java/org/onap/policy/clamp/controlloop/participant/simulator/simulation/SimulationHandler.java
@@ -20,14 +20,20 @@
 
 package org.onap.policy.clamp.controlloop.participant.simulator.simulation;
 
+import java.io.IOException;
 import java.util.List;
 import java.util.Set;
+import javax.ws.rs.core.Response;
+import lombok.Getter;
 import org.onap.policy.clamp.controlloop.common.handler.ControlLoopHandler;
+import org.onap.policy.clamp.controlloop.participant.intermediary.parameters.ParticipantIntermediaryParameters;
 import org.onap.policy.clamp.controlloop.participant.simulator.main.parameters.ParticipantSimulatorParameters;
 import org.onap.policy.clamp.controlloop.participant.simulator.simulation.rest.SimulationElementController;
 import org.onap.policy.clamp.controlloop.participant.simulator.simulation.rest.SimulationParticipantController;
 import org.onap.policy.common.endpoints.event.comm.TopicSink;
 import org.onap.policy.common.endpoints.listeners.MessageTypeDispatcher;
+import org.onap.policy.common.utils.services.Registry;
+import org.onap.policy.models.base.PfModelRuntimeException;
 
 /**
  * This class handles simulation of participants and control loop elements.
@@ -35,6 +41,11 @@ import org.onap.policy.common.endpoints.listeners.MessageTypeDispatcher;
  * <p/>It is effectively a singleton that is started at system start.
  */
 public class SimulationHandler extends ControlLoopHandler {
+    private final ParticipantIntermediaryParameters participantParameters;
+
+    @Getter
+    private SimulationProvider simulationProvider;
+
     /**
      * Create a handler.
      *
@@ -42,6 +53,11 @@ public class SimulationHandler extends ControlLoopHandler {
      */
     public SimulationHandler(ParticipantSimulatorParameters parameters) {
         super(parameters.getDatabaseProviderParameters());
+        participantParameters = parameters.getIntermediaryParameters();
+    }
+
+    public static SimulationHandler getInstance() {
+        return Registry.get(SimulationHandler.class.getName());
     }
 
     @Override
@@ -71,11 +87,15 @@ public class SimulationHandler extends ControlLoopHandler {
 
     @Override
     public void startProviders() {
-        // No providers on this handler
+        simulationProvider = new SimulationProvider(participantParameters);
     }
 
     @Override
     public void stopProviders() {
-        // No providers on this handler
+        try {
+            simulationProvider.close();
+        } catch (IOException e) {
+            throw new PfModelRuntimeException(Response.Status.INTERNAL_SERVER_ERROR, "Stop providers failed ", e);
+        }
     }
 }
diff --git a/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/intermediary/TestControlLoopUpdateListener.java b/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/intermediary/TestControlLoopUpdateListener.java
new file mode 100644
index 000000000..a307d3457
--- /dev/null
+++ b/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/intermediary/TestControlLoopUpdateListener.java
@@ -0,0 +1,91 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2021 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.clamp.controlloop.participant.simulator.main.intermediary;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.onap.policy.clamp.controlloop.common.exception.ControlLoopException;
+import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ControlLoopOrderedState;
+import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantControlLoopUpdate;
+import org.onap.policy.clamp.controlloop.participant.intermediary.comm.ControlLoopUpdateListener;
+import org.onap.policy.clamp.controlloop.participant.simulator.main.parameters.CommonTestData;
+import org.onap.policy.clamp.controlloop.participant.simulator.main.rest.TestListenerUtils;
+import org.onap.policy.common.endpoints.event.comm.Topic.CommInfrastructure;
+import org.onap.policy.common.utils.coder.CoderException;
+
+/**
+ * Class to perform unit test of {@link ControlLoopUpdateListener}.
+ */
+public class TestControlLoopUpdateListener {
+    private static ControlLoopUpdateListener clUpdateListener;
+    private static final CommInfrastructure INFRA = CommInfrastructure.NOOP;
+    private static final String TOPIC = "my-topic";
+    static CommonTestData commonTestData = new CommonTestData();
+
+    /**
+     * Method for setup.
+     *
+     * @throws ParticipantException if some error occurs while starting up the participant
+     * @throws FileNotFoundException if the file is missing
+     * @throws IOException if IO exception occurs
+     */
+    @BeforeClass
+    public static void setUp() throws ControlLoopException, FileNotFoundException, IOException {
+        TestListenerUtils.initParticipantHandler();
+        clUpdateListener = new ControlLoopUpdateListener(TestListenerUtils.getParticipantHandler());
+    }
+
+    @Test
+    public void testControlLoopUpdateListener_ParticipantIdNoMatch() throws CoderException {
+        ParticipantControlLoopUpdate participantControlLoopUpdateMsg = prepareMsg("DummyName");
+        clUpdateListener.onTopicEvent(INFRA, TOPIC, null, participantControlLoopUpdateMsg);
+
+        // Verify the content in participantHandler
+        assertNotEquals(participantControlLoopUpdateMsg.getParticipantId().getName(),
+                TestListenerUtils.getParticipantHandler().getParticipantId().getName());
+    }
+
+    @Test
+    public void testControlLoopUpdateListener() throws CoderException {
+        ParticipantControlLoopUpdate participantControlLoopUpdateMsg = prepareMsg("org.onap.PM_CDS_Blueprint");
+        clUpdateListener.onTopicEvent(INFRA, TOPIC, null, participantControlLoopUpdateMsg);
+
+        // Verify the content in participantHandler
+        assertEquals(TestListenerUtils.getParticipantHandler().getParticipantId(),
+                participantControlLoopUpdateMsg.getParticipantId());
+        assertThat(TestListenerUtils.getParticipantHandler().getControlLoopHandler().getControlLoops()
+                .getControlLoopList()).hasSize(1);
+    }
+
+    private ParticipantControlLoopUpdate prepareMsg(final String participantName) {
+        ParticipantControlLoopUpdate participantControlLoopUpdateMsg;
+        participantControlLoopUpdateMsg = TestListenerUtils.createControlLoopUpdateMsg();
+        participantControlLoopUpdateMsg.getParticipantId().setName(participantName);
+        participantControlLoopUpdateMsg.getControlLoop().setOrderedState(ControlLoopOrderedState.PASSIVE);
+        return participantControlLoopUpdateMsg;
+    }
+}
diff --git a/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/parameters/CommonTestData.java b/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/parameters/CommonTestData.java
index e0e001743..0a8754256 100644
--- a/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/parameters/CommonTestData.java
+++ b/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/parameters/CommonTestData.java
@@ -182,9 +182,7 @@ public class CommonTestData {
      * @return participant Id
      */
     public static ToscaConceptIdentifier getParticipantId() {
-        final ToscaConceptIdentifier participantId = new ToscaConceptIdentifier();
-        participantId.setName("CDSParticipant0");
-        participantId.setVersion("1.0.0");
+        final ToscaConceptIdentifier participantId = new ToscaConceptIdentifier("org.onap.PM_CDS_Blueprint", "1.0.0");
         return participantId;
     }
 
diff --git a/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/parameters/TestParticipantSimulatorParameterHandler.java b/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/parameters/TestParticipantSimulatorParameterHandler.java
index f8b11d723..e94939af8 100644
--- a/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/parameters/TestParticipantSimulatorParameterHandler.java
+++ b/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/parameters/TestParticipantSimulatorParameterHandler.java
@@ -20,6 +20,7 @@
 
 package org.onap.policy.clamp.controlloop.participant.simulator.main.parameters;
 
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
@@ -89,16 +90,15 @@ public class TestParticipantSimulatorParameterHandler {
     public void testParticipantVersion() throws ControlLoopException {
         final String[] participantConfigParameters = { "-v" };
         final ParticipantSimulatorCommandLineArguments arguments = new ParticipantSimulatorCommandLineArguments();
-        final String version = arguments.parse(participantConfigParameters);
-        assertTrue(version.startsWith("ONAP Tosca defined control loop Participant"));
+        assertThat(arguments.parse(participantConfigParameters)).startsWith(
+                        "ONAP Tosca defined control loop Participant");
     }
 
     @Test
     public void testParticipantHelp() throws ControlLoopException {
         final String[] participantConfigParameters = { "-h" };
         final ParticipantSimulatorCommandLineArguments arguments = new ParticipantSimulatorCommandLineArguments();
-        final String help = arguments.parse(participantConfigParameters);
-        assertTrue(help.startsWith("usage:"));
+        assertThat(arguments.parse(participantConfigParameters)).startsWith("usage:");
     }
 
     @Test
diff --git a/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/parameters/TestParticipantSimulatorParameters.java b/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/parameters/TestParticipantSimulatorParameters.java
index dcfbe94b7..2f47641a9 100644
--- a/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/parameters/TestParticipantSimulatorParameters.java
+++ b/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/parameters/TestParticipantSimulatorParameters.java
@@ -23,8 +23,8 @@ package org.onap.policy.clamp.controlloop.participant.simulator.main.parameters;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
 
+import java.util.Map;
 import org.junit.Test;
 import org.onap.policy.common.parameters.GroupValidationResult;
 
@@ -57,7 +57,7 @@ public class TestParticipantSimulatorParameters {
         final GroupValidationResult validationResult = participantParameters.validate();
         assertFalse(validationResult.isValid());
         assertEquals(null, participantParameters.getName());
-        assertTrue(validationResult.getResult().contains("is null"));
+        assertThat(validationResult.getResult()).contains("is null");
     }
 
     @Test
@@ -68,8 +68,8 @@ public class TestParticipantSimulatorParameters {
         final GroupValidationResult validationResult = participantParameters.validate();
         assertFalse(validationResult.isValid());
         assertEquals("", participantParameters.getName());
-        assertTrue(validationResult.getResult().contains(
-                "field \"name\" type \"java.lang.String\" value \"\" INVALID, " + "must be a non-blank string"));
+        assertThat(validationResult.getResult()).contains(
+                "field \"name\" type \"java.lang.String\" value \"\" INVALID, " + "must be a non-blank string");
     }
 
     @Test
@@ -81,4 +81,36 @@ public class TestParticipantSimulatorParameters {
         assertThat(participantParameters.validate().isValid()).isTrue();
         assertEquals("ParticipantNewGroup", participantParameters.getName());
     }
+
+    @Test
+    public void testParticipantParameterGroup_EmptyParticipantIntermediaryParameters() {
+        final Map<String, Object> map =
+                commonTestData.getParticipantParameterGroupMap(CommonTestData.PARTICIPANT_GROUP_NAME);
+        map.replace("intermediaryParameters", commonTestData.getIntermediaryParametersMap(true));
+        final ParticipantSimulatorParameters participantParameters =
+                commonTestData.toObject(map, ParticipantSimulatorParameters.class);
+        final GroupValidationResult validationResult = participantParameters.validate();
+        assertFalse(validationResult.isValid());
+        assertThat(validationResult.getResult()).contains(
+                        "\"org.onap.policy.clamp.controlloop.participant.simulator.main.parameters."
+                        + "ParticipantSimulatorParameters\""
+                        + " INVALID, parameter group has status INVALID");
+    }
+
+    @Test
+    public void testParticipantParameterGroupp_EmptyTopicParameters() {
+        final Map<String, Object> map =
+                commonTestData.getParticipantParameterGroupMap(CommonTestData.PARTICIPANT_GROUP_NAME);
+        final Map<String, Object> intermediaryParametersMap = commonTestData.getIntermediaryParametersMap(false);
+        intermediaryParametersMap.put("clampControlLoopTopics", commonTestData.getTopicParametersMap(true));
+        map.replace("intermediaryParameters", intermediaryParametersMap);
+
+        final ParticipantSimulatorParameters participantParameters =
+                commonTestData.toObject(map, ParticipantSimulatorParameters.class);
+        final GroupValidationResult validationResult = participantParameters.validate();
+        assertFalse(validationResult.isValid());
+        assertThat(validationResult.getResult())
+                .contains("\"org.onap.policy.common.endpoints.parameters.TopicParameterGroup\" INVALID, "
+                        + "parameter group has status INVALID");
+    }
 }
diff --git a/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/rest/CommonParticipantRestServer.java b/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/rest/CommonParticipantRestServer.java
index 7aae32629..ae004de49 100644
--- a/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/rest/CommonParticipantRestServer.java
+++ b/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/rest/CommonParticipantRestServer.java
@@ -21,7 +21,7 @@
 
 package org.onap.policy.clamp.controlloop.participant.simulator.main.rest;
 
-import static org.junit.Assert.assertTrue;
+import static org.assertj.core.api.Assertions.assertThat;
 
 import java.io.File;
 import java.io.FileNotFoundException;
@@ -127,8 +127,7 @@ public class CommonParticipantRestServer {
      */
     protected void testSwagger(final String endpoint) throws Exception {
         final Invocation.Builder invocationBuilder = sendFqeRequest(httpPrefix + "swagger.yaml", true);
-        final String resp = invocationBuilder.get(String.class);
-        assertTrue(resp.contains(ENDPOINT_PREFIX + endpoint + ":"));
+        assertThat(invocationBuilder.get(String.class)).contains(ENDPOINT_PREFIX + endpoint + ":");
     }
 
     /**
diff --git a/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/rest/RestControllerTest.java b/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/rest/RestControllerTest.java
index c7a39c48b..1311eee35 100644
--- a/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/rest/RestControllerTest.java
+++ b/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/rest/RestControllerTest.java
@@ -27,14 +27,37 @@ import javax.ws.rs.Produces;
 import javax.ws.rs.core.MediaType;
 import javax.ws.rs.core.Response;
 import javax.ws.rs.core.Response.ResponseBuilder;
+import org.junit.AfterClass;
 import org.junit.Before;
+import org.junit.BeforeClass;
 import org.junit.Test;
+import org.mockito.Mockito;
+import org.onap.policy.clamp.controlloop.participant.simulator.simulation.SimulationHandler;
+import org.onap.policy.common.utils.services.Registry;
 
 public class RestControllerTest {
 
     private RestController ctlr;
     private ResponseBuilder bldr;
 
+    /**
+     * Setup before class, instantiate SimulationHandler.
+     *
+     */
+    @BeforeClass
+    public static void setUpBeforeClass() throws Exception {
+        Registry.newRegistry();
+        Registry.register(SimulationHandler.class.getName(), Mockito.mock(SimulationHandler.class));
+    }
+
+    @AfterClass
+    public static void teardownAfterClass() throws Exception {
+        Registry.unregister(SimulationHandler.class.getName());
+    }
+
+    /**
+     * set Up.
+     */
     @Before
     public void setUp() {
         ctlr = new RestController();
diff --git a/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/rest/TestListenerUtils.java b/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/rest/TestListenerUtils.java
index 7b7dd2d84..3ee39d57e 100644
--- a/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/rest/TestListenerUtils.java
+++ b/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/rest/TestListenerUtils.java
@@ -22,18 +22,29 @@ package org.onap.policy.clamp.controlloop.participant.simulator.main.rest;
 
 import static org.junit.Assert.assertTrue;
 
+import java.io.File;
 import java.io.FileNotFoundException;
+import java.time.Instant;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.UUID;
+import lombok.Getter;
 import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ControlLoop;
 import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ControlLoopElement;
 import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ControlLoopOrderedState;
 import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ControlLoopState;
+import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ParticipantState;
+import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantControlLoopStateChange;
+import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantControlLoopUpdate;
+import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantStateChange;
+import org.onap.policy.clamp.controlloop.participant.intermediary.handler.ParticipantHandler;
 import org.onap.policy.clamp.controlloop.participant.simulator.main.parameters.CommonTestData;
+import org.onap.policy.clamp.controlloop.participant.simulator.main.parameters.ParticipantSimulatorParameters;
+import org.onap.policy.clamp.controlloop.participant.simulator.simulation.SimulationProvider;
 import org.onap.policy.common.utils.coder.Coder;
+import org.onap.policy.common.utils.coder.CoderException;
 import org.onap.policy.common.utils.coder.StandardCoder;
 import org.onap.policy.common.utils.coder.YamlJsonTranslator;
 import org.onap.policy.common.utils.resources.ResourceUtils;
@@ -48,11 +59,28 @@ public class TestListenerUtils {
     private static final YamlJsonTranslator yamlTranslator = new YamlJsonTranslator();
     private static final Coder CODER = new StandardCoder();
     static CommonTestData commonTestData = new CommonTestData();
-    private static RestController restController;
     private static final Logger LOGGER = LoggerFactory.getLogger(TestListenerUtils.class);
 
     private TestListenerUtils() {}
 
+    @Getter
+    private static ParticipantHandler participantHandler;
+
+    /**
+     * Method to initialize participantHandler.
+     */
+    public static void initParticipantHandler() {
+
+        final ParticipantSimulatorParameters participantParameters = commonTestData.toObject(
+                commonTestData.getParticipantParameterGroupMap(CommonTestData.PARTICIPANT_GROUP_NAME),
+                ParticipantSimulatorParameters.class);
+
+        SimulationProvider simulationProvider =
+                new SimulationProvider(participantParameters.getIntermediaryParameters());
+
+        participantHandler = simulationProvider.getIntermediaryApi().getParticipantHandler();
+    }
+
     /**
      * Method to create a controlLoop from a yaml file.
      *
@@ -60,10 +88,10 @@ public class TestListenerUtils {
      */
     public static ControlLoop createControlLoop() {
         ControlLoop controlLoop = new ControlLoop();
-        List<ControlLoopElement> elements =  new ArrayList<>();
+        List<ControlLoopElement> elements = new ArrayList<>();
         ToscaServiceTemplate toscaServiceTemplate = testControlLoopRead();
-        Map<String, ToscaNodeTemplate> nodeTemplatesMap = toscaServiceTemplate
-                .getToscaTopologyTemplate().getNodeTemplates();
+        Map<String, ToscaNodeTemplate> nodeTemplatesMap =
+                toscaServiceTemplate.getToscaTopologyTemplate().getNodeTemplates();
         for (Map.Entry<String, ToscaNodeTemplate> toscaInputEntry : nodeTemplatesMap.entrySet()) {
             ControlLoopElement clElement = new ControlLoopElement();
             clElement.setId(UUID.randomUUID());
@@ -91,9 +119,107 @@ public class TestListenerUtils {
         return controlLoop;
     }
 
+    /**
+     * Method to create ParticipantStateChange message from the arguments passed.
+     *
+     * @param participantState participant State
+     *
+     * @return ParticipantStateChange message
+     */
+    public static ParticipantStateChange createParticipantStateChangeMsg(final ParticipantState participantState) {
+        final ParticipantStateChange participantStateChangeMsg = new ParticipantStateChange();
+        ToscaConceptIdentifier participantId = new ToscaConceptIdentifier("org.onap.PM_CDS_Blueprint", "1.0.0");
+
+        participantStateChangeMsg.setParticipantId(participantId);
+        participantStateChangeMsg.setTimestamp(Instant.now());
+        participantStateChangeMsg.setState(participantState);
+
+        return participantStateChangeMsg;
+    }
+
+    /**
+     * Method to create ControlLoopStateChange message from the arguments passed.
+     *
+     * @param controlLoopOrderedState controlLoopOrderedState
+     *
+     * @return ParticipantControlLoopStateChange message
+     */
+    public static ParticipantControlLoopStateChange createControlLoopStateChangeMsg(
+            final ControlLoopOrderedState controlLoopOrderedState) {
+        final ParticipantControlLoopStateChange participantClStateChangeMsg = new ParticipantControlLoopStateChange();
+
+        ToscaConceptIdentifier controlLoopId = new ToscaConceptIdentifier("PMSHInstance0", "1.0.0");
+        ToscaConceptIdentifier participantId = new ToscaConceptIdentifier("org.onap.PM_CDS_Blueprint", "1.0.0");
+
+        participantClStateChangeMsg.setControlLoopId(controlLoopId);
+        participantClStateChangeMsg.setParticipantId(participantId);
+        participantClStateChangeMsg.setTimestamp(Instant.now());
+        participantClStateChangeMsg.setOrderedState(controlLoopOrderedState);
+
+        return participantClStateChangeMsg;
+    }
+
+    /**
+     * Method to create ControlLoopUpdateMsg.
+     *
+     * @return ParticipantControlLoopUpdate message
+     */
+    public static ParticipantControlLoopUpdate createControlLoopUpdateMsg() {
+        final ParticipantControlLoopUpdate clUpdateMsg = new ParticipantControlLoopUpdate();
+        ToscaConceptIdentifier controlLoopId = new ToscaConceptIdentifier("PMSHInstance0", "1.0.0.");
+        ToscaConceptIdentifier participantId = new ToscaConceptIdentifier("org.onap.PM_CDS_Blueprint", "1.0.0");
+
+        clUpdateMsg.setControlLoopId(controlLoopId);
+        clUpdateMsg.setParticipantId(participantId);
+
+        ControlLoop controlLoop = new ControlLoop();
+        List<ControlLoopElement> elements = new ArrayList<>();
+        ToscaServiceTemplate toscaServiceTemplate = testControlLoopRead();
+        Map<String, ToscaNodeTemplate> nodeTemplatesMap =
+                toscaServiceTemplate.getToscaTopologyTemplate().getNodeTemplates();
+        for (Map.Entry<String, ToscaNodeTemplate> toscaInputEntry : nodeTemplatesMap.entrySet()) {
+            ControlLoopElement clElement = new ControlLoopElement();
+            clElement.setId(UUID.randomUUID());
+
+            ToscaConceptIdentifier clElementParticipantId = new ToscaConceptIdentifier();
+            clElementParticipantId.setName(toscaInputEntry.getKey());
+            clElementParticipantId.setVersion(toscaInputEntry.getValue().getVersion());
+            clElement.setParticipantId(clElementParticipantId);
+
+            clElement.setDefinition(clElementParticipantId);
+            clElement.setState(ControlLoopState.UNINITIALISED);
+            clElement.setDescription(toscaInputEntry.getValue().getDescription());
+            clElement.setOrderedState(ControlLoopOrderedState.UNINITIALISED);
+            elements.add(clElement);
+        }
+        controlLoop.setElements(elements);
+        controlLoop.setName("PMSHInstance0");
+        controlLoop.setVersion("1.0.0");
+        controlLoop.setDefinition(controlLoopId);
+        clUpdateMsg.setControlLoop(controlLoop);
+        clUpdateMsg.setControlLoopDefinition(toscaServiceTemplate);
+
+        return clUpdateMsg;
+    }
+
+    /**
+     * Method to create ParticipantControlLoopUpdate using the arguments passed.
+     *
+     * @param jsonFilePath the path of the controlloop content
+     *
+     * @return ParticipantControlLoopUpdate message
+     * @throws CoderException exception while reading the file to object
+     */
+    public static ParticipantControlLoopUpdate createParticipantClUpdateMsgFromJson(String jsonFilePath)
+            throws CoderException {
+        ParticipantControlLoopUpdate participantControlLoopUpdateMsg =
+                CODER.decode(new File(jsonFilePath), ParticipantControlLoopUpdate.class);
+        return participantControlLoopUpdateMsg;
+    }
+
     private static ToscaServiceTemplate testControlLoopRead() {
-        Set<String> controlLoopDirectoryContents = ResourceUtils
-                .getDirectoryContents("src/test/resources/rest/servicetemplates");
+        Set<String> controlLoopDirectoryContents =
+                ResourceUtils.getDirectoryContents("src/test/resources/rest/servicetemplates");
 
         boolean atLeastOneControlLoopTested = false;
         ToscaServiceTemplate toscaServiceTemplate = null;
diff --git a/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/rest/TestSimulationRestController.java b/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/rest/TestSimulationRestController.java
index 7adc88d09..1b2b87cfb 100644
--- a/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/rest/TestSimulationRestController.java
+++ b/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/rest/TestSimulationRestController.java
@@ -1,6 +1,6 @@
 /*-
  * ============LICENSE_START=======================================================
- *  Copyright (C) 2019 Nordix Foundation.
+ *  Copyright (C) 2021 Nordix Foundation.
  * ================================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,12 +20,14 @@
 
 package org.onap.policy.clamp.controlloop.participant.simulator.main.rest;
 
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
 
-import java.util.ArrayList;
 import java.util.List;
 import javax.ws.rs.client.Entity;
 import javax.ws.rs.client.Invocation;
+import javax.ws.rs.core.GenericType;
 import javax.ws.rs.core.MediaType;
 import javax.ws.rs.core.Response;
 import org.junit.AfterClass;
@@ -36,8 +38,12 @@ import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ControlLoop
 import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ControlLoopOrderedState;
 import org.onap.policy.clamp.controlloop.models.controlloop.concepts.Participant;
 import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ParticipantState;
+import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantControlLoopUpdate;
 import org.onap.policy.clamp.controlloop.models.messages.rest.TypedSimpleResponse;
+import org.onap.policy.clamp.controlloop.participant.intermediary.comm.ControlLoopUpdateListener;
 import org.onap.policy.clamp.controlloop.participant.simulator.main.parameters.CommonTestData;
+import org.onap.policy.clamp.controlloop.participant.simulator.simulation.SimulationHandler;
+import org.onap.policy.clamp.controlloop.participant.simulator.simulation.SimulationProvider;
 import org.onap.policy.common.endpoints.event.comm.Topic.CommInfrastructure;
 import org.onap.policy.models.tosca.authorative.concepts.ToscaConceptIdentifier;
 
@@ -45,20 +51,30 @@ import org.onap.policy.models.tosca.authorative.concepts.ToscaConceptIdentifier;
  * Class to perform unit test of {@link TestSimulationRestController}.
  */
 public class TestSimulationRestController extends CommonParticipantRestServer {
+
+    private static ControlLoopUpdateListener clUpdateListener;
     private static final String PARTICIPANTS_ENDPOINT = "participants";
     private static final String ELEMENTS_ENDPOINT = "elements";
     private static final CommInfrastructure INFRA = CommInfrastructure.NOOP;
     private static final String TOPIC = "my-topic";
     static CommonTestData commonTestData = new CommonTestData();
-    private static RestController restController;
 
     /**
-     * Setup before class, instantiate SimulationProvider.
+     * Setup before class.
      *
      */
     @BeforeClass
     public static void setUpBeforeClass() throws Exception {
         CommonParticipantRestServer.setUpBeforeClass();
+        clUpdateListener = new ControlLoopUpdateListener(
+                SimulationHandler.getInstance()
+                .getSimulationProvider()
+                .getIntermediaryApi()
+                .getParticipantHandler());
+        ParticipantControlLoopUpdate participantControlLoopUpdateMsg =
+                TestListenerUtils.createControlLoopUpdateMsg();
+        participantControlLoopUpdateMsg.getControlLoop().setOrderedState(ControlLoopOrderedState.PASSIVE);
+        clUpdateListener.onTopicEvent(INFRA, TOPIC, null, participantControlLoopUpdateMsg);
     }
 
     @AfterClass
@@ -88,35 +104,38 @@ public class TestSimulationRestController extends CommonParticipantRestServer {
 
         // GET REST call for querying the participants
         Invocation.Builder invocationBuilder =
-                super.sendRequest(PARTICIPANTS_ENDPOINT + "/" + participant.getKey().getName()
-                + "/" + participant.getVersion());
+            super.sendRequest(PARTICIPANTS_ENDPOINT + "/" + participant.getKey().getName()
+                    + "/" + participant.getVersion());
 
         Response rawresp = invocationBuilder.buildGet().invoke();
-        // Response is not OK, as handling is not done
-        assertEquals(Response.Status.INTERNAL_SERVER_ERROR.getStatusCode(), rawresp.getStatus());
+        assertEquals(Response.Status.OK.getStatusCode(), rawresp.getStatus());
+        List<Participant> returnValue = rawresp.readEntity(new GenericType<List<Participant>>() {});
+        assertNotNull(returnValue);
+        assertThat(returnValue).hasSize(1);
+        // Verify the result of GET participants with what is stored
+        assertEquals(participant.getDefinition(), returnValue.get(0).getDefinition());
     }
 
     @Test
     public void testQueryControlLoopElements() throws Exception {
         // GET REST call for querying the controlLoop elements
-        Invocation.Builder invocationBuilder =
-                super.sendRequest(ELEMENTS_ENDPOINT + "/" + "PMSHInstance0" + "/" + "1.0.0");
+        Invocation.Builder invocationBuilder = super.sendRequest(ELEMENTS_ENDPOINT + "/"
+                                                        + "PMSHInstance0" + "/" + "1.0.0");
 
         Response rawresp = invocationBuilder.buildGet().invoke();
-        // Response is not OK, as handling is not done
-        assertEquals(Response.Status.INTERNAL_SERVER_ERROR.getStatusCode(), rawresp.getStatus());
+        assertEquals(Response.Status.OK.getStatusCode(), rawresp.getStatus());
+        List<ControlLoopElement> returnValue = rawresp.readEntity(new GenericType<List<ControlLoopElement>>() {});
+        assertNotNull(returnValue);
+        // Verify the result of GET controlloop elements with what is stored
+        assertThat(returnValue).hasSize(4);
+        assertEquals("org.onap.PM_Subscription_Handler", returnValue.get(0).getDefinition().getName());
     }
 
     @Test
     public void testUpdateParticipant() throws Exception {
-        Participant participant = new Participant();
-        ToscaConceptIdentifier participantId = CommonTestData.getParticipantId();
-        participant.setDefinition(participantId);
-        participant.setName(participantId.getName());
-        participant.setVersion(participantId.getVersion());
-
-        List<Participant> participants = new ArrayList<>();
-        participants.add(participant);
+        SimulationProvider provider = SimulationHandler.getInstance().getSimulationProvider();
+        List<Participant> participants = provider.getParticipants(CommonTestData.getParticipantId().getName(),
+                CommonTestData.getParticipantId().getVersion());
         assertEquals(ParticipantState.UNKNOWN, participants.get(0).getParticipantState());
         // Change the state of the participant to PASSIVE from UNKNOWN
         participants.get(0).setParticipantState(ParticipantState.PASSIVE);
@@ -126,14 +145,19 @@ public class TestSimulationRestController extends CommonParticipantRestServer {
         Invocation.Builder invocationBuilder = sendRequest(PARTICIPANTS_ENDPOINT);
         Response rawresp = invocationBuilder.put(entParticipant);
         TypedSimpleResponse<Participant> resp = rawresp.readEntity(TypedSimpleResponse.class);
-        // Response is not OK, as handling is not done
-        assertEquals(Response.Status.INTERNAL_SERVER_ERROR.getStatusCode(), rawresp.getStatus());
+        assertEquals(Response.Status.OK.getStatusCode(), rawresp.getStatus());
+        assertNotNull(resp.getResponse());
+        // Verify the response and state returned by PUT REST call for updating participants
+        assertThat(resp.toString()).contains("definition={name=org.onap.PM_CDS_Blueprint, version=1.0.0}");
+        assertThat(resp.toString()).contains("participantState=PASSIVE");
     }
 
     @Test
     public void testUpdateControlLoopElement() throws Exception {
         ControlLoop controlLoop = TestListenerUtils.createControlLoop();
-        List<ControlLoopElement> controlLoopElements = controlLoop.getElements();
+        SimulationProvider provider = SimulationHandler.getInstance().getSimulationProvider();
+        List<ControlLoopElement> controlLoopElements = provider.getControlLoopElements(
+                controlLoop.getDefinition().getName(), controlLoop.getDefinition().getVersion());
 
         // Check the initial state on the ControlLoopElement, which is UNINITIALISED
         assertEquals(ControlLoopOrderedState.UNINITIALISED, controlLoopElements.get(0).getOrderedState());
@@ -146,8 +170,10 @@ public class TestSimulationRestController extends CommonParticipantRestServer {
         Invocation.Builder invocationBuilder = sendRequest(ELEMENTS_ENDPOINT);
         Response rawresp = invocationBuilder.put(entClElement);
         TypedSimpleResponse<ControlLoopElement> resp = rawresp.readEntity(TypedSimpleResponse.class);
-        // Response is not OK, as handling is not done
-        assertEquals(Response.Status.INTERNAL_SERVER_ERROR.getStatusCode(), rawresp.getStatus());
+        assertEquals(Response.Status.OK.getStatusCode(), rawresp.getStatus());
+        assertNotNull(resp.getResponse());
+        // Verify the response and state returned by PUT REST call for updating participants
+        assertThat(resp.toString()).contains("definition={name=org.onap.PM_Subscription_Handler, version=0.0.0}");
+        assertThat(resp.toString()).contains("orderedState=PASSIVE");
     }
 }
-
diff --git a/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/startstop/TestMain.java b/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/startstop/TestMain.java
index 137bec205..5a5ad8931 100644
--- a/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/startstop/TestMain.java
+++ b/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/java/org/onap/policy/clamp/controlloop/participant/simulator/main/startstop/TestMain.java
@@ -23,13 +23,9 @@ package org.onap.policy.clamp.controlloop.participant.simulator.main.startstop;
 import static org.assertj.core.api.Assertions.assertThatCode;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
 
-import org.junit.AfterClass;
-import org.junit.BeforeClass;
 import org.junit.Test;
-import org.onap.policy.clamp.controlloop.common.ControlLoopConstants;
 import org.onap.policy.clamp.controlloop.common.exception.ControlLoopRuntimeException;
 import org.onap.policy.common.utils.resources.MessageConstants;
 
diff --git a/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/resources/parameters/TestParameters.json b/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/resources/parameters/TestParameters.json
index 82bb917a9..8c594044b 100644
--- a/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/resources/parameters/TestParameters.json
+++ b/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/resources/parameters/TestParameters.json
@@ -13,11 +13,11 @@
         "reportingTimeInterval": 120000,
         "description": "Participant Description",
         "participantId": {
-            "name": "CDSParticipant0",
+            "name": "org.onap.PM_CDS_Blueprint",
             "version": "1.0.0"
         },
         "participantType": {
-            "name": "CDSParticipant0",
+            "name": "org.onap.PM_CDS_Blueprint",
             "version": "1.0.0"
         },
         "clampControlLoopTopics": {
diff --git a/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/resources/parameters/TestParametersStd.json b/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/resources/parameters/TestParametersStd.json
index 1599fc395..0295a8f91 100644
--- a/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/resources/parameters/TestParametersStd.json
+++ b/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/resources/parameters/TestParametersStd.json
@@ -13,11 +13,11 @@
         "reportingTimeInterval": 120000,
         "description": "Participant Description",
         "participantId": {
-            "name": "CDSParticipant0",
+            "name": "org.onap.PM_CDS_Blueprint",
             "version": "1.0.0"
         },
         "participantType": {
-            "name": "CDSParticipant0",
+            "name": "org.onap.PM_CDS_Blueprint",
             "version": "1.0.0"
         },
         "clampControlLoopTopics": {
diff --git a/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/resources/rest/servicetemplates/pm_control_loop_tosca.yaml b/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/resources/rest/servicetemplates/pm_control_loop_tosca.yaml
index 01f825fc9..99dd0ed68 100644
--- a/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/resources/rest/servicetemplates/pm_control_loop_tosca.yaml
+++ b/tosca-controlloop/participant/participant-impl/participant-impl-simulator/src/test/resources/rest/servicetemplates/pm_control_loop_tosca.yaml
@@ -440,7 +440,7 @@ topology_template:
           occurrences:
           - 0.0
           version: 0.0.0
-      version: 0.0.0
+      version: 1.0.0
     org.onap.controlloop0:
       type: org.onap.APP
       properties:
diff --git a/tosca-controlloop/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/api/ParticipantIntermediaryApi.java b/tosca-controlloop/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/api/ParticipantIntermediaryApi.java
index 6c3e029fe..7ea8b4f35 100644
--- a/tosca-controlloop/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/api/ParticipantIntermediaryApi.java
+++ b/tosca-controlloop/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/api/ParticipantIntermediaryApi.java
@@ -30,6 +30,7 @@ import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ControlLoop
 import org.onap.policy.clamp.controlloop.models.controlloop.concepts.Participant;
 import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ParticipantState;
 import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ParticipantStatistics;
+import org.onap.policy.clamp.controlloop.participant.intermediary.handler.ParticipantHandler;
 import org.onap.policy.clamp.controlloop.participant.intermediary.parameters.ParticipantIntermediaryParameters;
 import org.onap.policy.models.tosca.authorative.concepts.ToscaConceptIdentifier;
 
@@ -42,12 +43,12 @@ public interface ParticipantIntermediaryApi {
      *
      * @param parameters the parameters for the intermediary
      */
-    public void init(ParticipantIntermediaryParameters parameters);
+    void init(ParticipantIntermediaryParameters parameters);
 
     /**
      * Close the intermediary.
      */
-    public void close();
+    void close();
 
     /**
      * Get participants loops from the intermediary API.
@@ -56,23 +57,23 @@ public interface ParticipantIntermediaryApi {
      * @param version the participant version, null for all
      * @return the participants
      */
-    public List<Participant> getParticipants(String name, String version);
+    List<Participant> getParticipants(String name, String version);
 
     /**
      * Update the state of a participant.
      *
      * @param definition the definition of the participant to update the state on
      * @param state the state of the participant
-     * @return updated participant
+     * @return the participant
      */
-    public Participant updateParticipantState(ToscaConceptIdentifier definition, ParticipantState state);
+    Participant updateParticipantState(ToscaConceptIdentifier definition, ParticipantState state);
 
     /**
      * Update the statistics of a participant.
      *
      * @param participantStatistics the statistics of the participant
      */
-    public void updateParticipantStatistics(ParticipantStatistics participantStatistics);
+    void updateParticipantStatistics(ParticipantStatistics participantStatistics);
 
     /**
      * Get control loops from the intermediary API.
@@ -81,7 +82,7 @@ public interface ParticipantIntermediaryApi {
      * @param version the control loop element version, null for all
      * @return the control loop elements
      */
-    public ControlLoops getControlLoops(String name, String version);
+    ControlLoops getControlLoops(String name, String version);
 
     /**
      * Get control loop elements from the intermediary API.
@@ -90,7 +91,7 @@ public interface ParticipantIntermediaryApi {
      * @param version the control loop element version, null for all
      * @return the control loop elements
      */
-    public List<ControlLoopElement> getControlLoopElements(String name, String version);
+    List<ControlLoopElement> getControlLoopElements(String name, String version);
 
     /**
      * Update the state of a control loop.
@@ -99,7 +100,7 @@ public interface ParticipantIntermediaryApi {
      * @param state the state of the control loop
      * @return ControlLoop updated control loop
      */
-    public ControlLoop updateControlLoopState(ToscaConceptIdentifier definition, ControlLoopOrderedState state);
+    ControlLoop updateControlLoopState(ToscaConceptIdentifier definition, ControlLoopOrderedState state);
 
     /**
      * Update the state of a control loop element.
@@ -108,12 +109,21 @@ public interface ParticipantIntermediaryApi {
      * @param state the state of the control loop element
      * @return ControlLoopElement updated control loop element
      */
-    public ControlLoopElement updateControlLoopElementState(UUID id, ControlLoopOrderedState state);
+    ControlLoopElement updateControlLoopElementState(UUID id, ControlLoopOrderedState state);
 
     /**
      * Update the control loop element statistics.
      *
      * @param elementStatistics the updated statistics
      */
-    public void updateControlLoopElementStatistics(ClElementStatistics elementStatistics);
+    void updateControlLoopElementStatistics(ClElementStatistics elementStatistics);
+
+    /**
+     * Returns participantHandler, This will not be used in real world, but for junits,
+     * if participantHandler is not returned, there is no way to test state change messages
+     * without dmaap simulator.
+     *
+     * @return ParticipantHandler returns a participantHandler
+     */
+    ParticipantHandler getParticipantHandler();
 }
diff --git a/tosca-controlloop/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/api/impl/ParticipantIntermediaryApiImpl.java b/tosca-controlloop/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/api/impl/ParticipantIntermediaryApiImpl.java
index 939f927e6..9e494862e 100644
--- a/tosca-controlloop/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/api/impl/ParticipantIntermediaryApiImpl.java
+++ b/tosca-controlloop/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/api/impl/ParticipantIntermediaryApiImpl.java
@@ -32,6 +32,8 @@ import org.onap.policy.clamp.controlloop.models.controlloop.concepts.Participant
 import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ParticipantState;
 import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ParticipantStatistics;
 import org.onap.policy.clamp.controlloop.participant.intermediary.api.ParticipantIntermediaryApi;
+import org.onap.policy.clamp.controlloop.participant.intermediary.handler.IntermediaryActivator;
+import org.onap.policy.clamp.controlloop.participant.intermediary.handler.ParticipantHandler;
 import org.onap.policy.clamp.controlloop.participant.intermediary.parameters.ParticipantIntermediaryParameters;
 import org.onap.policy.models.tosca.authorative.concepts.ToscaConceptIdentifier;
 
@@ -40,49 +42,74 @@ import org.onap.policy.models.tosca.authorative.concepts.ToscaConceptIdentifier;
  */
 public class ParticipantIntermediaryApiImpl implements ParticipantIntermediaryApi {
 
+    // The activator for the participant intermediary
+    private IntermediaryActivator activator;
+
     @Override
     public void init(ParticipantIntermediaryParameters parameters) {
+        activator = new IntermediaryActivator(parameters);
+
+        activator.start();
     }
 
     @Override
     public void close() {
+        activator.shutdown();
     }
 
     @Override
     public List<Participant> getParticipants(String name, String version) {
-        return Collections.emptyList();
+        return List.of(activator.getParticipantHandler().getParticipant(name, version));
     }
 
     @Override
     public Participant updateParticipantState(ToscaConceptIdentifier definition, ParticipantState state) {
-        return null;
+        return activator.getParticipantHandler().updateParticipantState(definition, state);
     }
 
     @Override
     public void updateParticipantStatistics(ParticipantStatistics participantStatistics) {
+        // TODO Auto-generated method stub
     }
 
     @Override
     public ControlLoops getControlLoops(String name, String version) {
-        return null;
+        return activator.getParticipantHandler().getControlLoopHandler().getControlLoops();
     }
 
     @Override
     public List<ControlLoopElement> getControlLoopElements(String name, String version) {
+        List<ControlLoop> controlLoops = activator.getParticipantHandler()
+                .getControlLoopHandler().getControlLoops().getControlLoopList();
+
+        for (ControlLoop controlLoop : controlLoops) {
+            if (controlLoop.getDefinition().getName().equals(name)) {
+                return controlLoop.getElements();
+            }
+        }
         return Collections.emptyList();
     }
 
     @Override
     public ControlLoop updateControlLoopState(ToscaConceptIdentifier definition, ControlLoopOrderedState state) {
-        return null;
+        return activator.getParticipantHandler().getControlLoopHandler()
+                .updateControlLoopState(definition, state);
     }
 
     @Override
     public ControlLoopElement updateControlLoopElementState(UUID id, ControlLoopOrderedState state) {
-        return null;
+        return activator.getParticipantHandler().getControlLoopHandler()
+                .updateControlLoopElementState(id, state);
     }
 
     @Override
     public void updateControlLoopElementStatistics(ClElementStatistics elementStatistics) {
+        activator.getParticipantHandler().getControlLoopHandler()
+        .updateControlLoopElementStatistics(elementStatistics);
+    }
+
+    @Override
+    public ParticipantHandler getParticipantHandler() {
+        return activator.getParticipantHandler();
     }
 }
diff --git a/tosca-controlloop/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/comm/ControlLoopUpdateListener.java b/tosca-controlloop/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/comm/ControlLoopUpdateListener.java
new file mode 100644
index 000000000..2ba98891f
--- /dev/null
+++ b/tosca-controlloop/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/comm/ControlLoopUpdateListener.java
@@ -0,0 +1,61 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2021 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.clamp.controlloop.participant.intermediary.comm;
+
+import java.io.Closeable;
+import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantControlLoopUpdate;
+import org.onap.policy.clamp.controlloop.participant.intermediary.handler.ParticipantHandler;
+import org.onap.policy.common.endpoints.event.comm.Topic.CommInfrastructure;
+import org.onap.policy.common.endpoints.listeners.ScoListener;
+import org.onap.policy.common.utils.coder.StandardCoderObject;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Listener for Control Loop Update messages sent by CLAMP.
+ */
+public class ControlLoopUpdateListener extends ScoListener<ParticipantControlLoopUpdate> implements Closeable {
+    private static final Logger LOGGER = LoggerFactory.getLogger(ControlLoopUpdateListener.class);
+
+    private final ParticipantHandler participantHandler;
+
+    /**
+     * Constructs the object.
+     *
+     * @param participantHandler the handler for managing the state of the participant
+     */
+    public ControlLoopUpdateListener(final ParticipantHandler participantHandler) {
+        super(ParticipantControlLoopUpdate.class);
+        this.participantHandler = participantHandler;
+    }
+
+    @Override
+    public void onTopicEvent(final CommInfrastructure infra, final String topic, final StandardCoderObject sco,
+            final ParticipantControlLoopUpdate participantControlLoopUpdateMsg) {
+        LOGGER.debug("Control Loop update received from CLAMP - {}", participantControlLoopUpdateMsg);
+        participantHandler.getControlLoopHandler().handleControlLoopUpdate(participantControlLoopUpdateMsg);
+    }
+
+    @Override
+    public void close() {
+        // No explicit action on this class
+    }
+}
diff --git a/tosca-controlloop/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/comm/MessageSender.java b/tosca-controlloop/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/comm/MessageSender.java
new file mode 100644
index 000000000..20490f81d
--- /dev/null
+++ b/tosca-controlloop/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/comm/MessageSender.java
@@ -0,0 +1,118 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2021 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.clamp.controlloop.participant.intermediary.comm;
+
+import java.io.Closeable;
+import java.util.TimerTask;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantResponseDetails;
+import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantResponseStatus;
+import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantStatus;
+import org.onap.policy.clamp.controlloop.participant.intermediary.handler.ParticipantHandler;
+import org.onap.policy.models.tosca.authorative.concepts.ToscaConceptIdentifier;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * This class sends messages from participants to CLAMP.
+ */
+public class MessageSender extends TimerTask implements Closeable {
+    private static final Logger LOGGER = LoggerFactory.getLogger(MessageSender.class);
+
+    private final ParticipantHandler participantHandler;
+    private final ParticipantStatusPublisher publisher;
+    private ScheduledExecutorService timerPool;
+
+    /**
+     * Constructor, set the publisher.
+     *
+     * @param participantHandler the participant handler to use for gathering information
+     * @param publisher the publisher to use for sending messages
+     * @param interval time interval to send Participant Status periodic messages
+     */
+    public MessageSender(ParticipantHandler participantHandler, ParticipantStatusPublisher publisher,
+            long interval) {
+        this.participantHandler = participantHandler;
+        this.publisher = publisher;
+
+        // Kick off the timer
+        timerPool = makeTimerPool();
+        timerPool.scheduleAtFixedRate(this, 0, interval, TimeUnit.SECONDS);
+    }
+
+    @Override
+    public void run() {
+        LOGGER.debug("Sent heartbeat to CLAMP");
+
+        ParticipantResponseDetails response = new ParticipantResponseDetails();
+
+        response.setResponseTo(null);
+        response.setResponseStatus(ParticipantResponseStatus.PERIODIC);
+        response.setResponseMessage("Periodic response from participant");
+    }
+
+    @Override
+    public void close() {
+        timerPool.shutdown();
+    }
+
+    /**
+     * Send a response message for this participant.
+     *
+     * @param response the details to include in the response message
+     */
+    public void sendResponse(ParticipantResponseDetails response) {
+        sendResponse(null, response);
+    }
+
+    /**
+     * Send a response message for this participant.
+     *
+     * @param controlLoopId the control loop to which this message is a response
+     * @param response the details to include in the response message
+     */
+    public void sendResponse(ToscaConceptIdentifier controlLoopId, ParticipantResponseDetails response) {
+        ParticipantStatus status = new ParticipantStatus();
+
+        // Participant related fields
+        status.setParticipantId(participantHandler.getParticipantId());
+        status.setState(participantHandler.getState());
+        status.setHealthStatus(participantHandler.getHealthStatus());
+
+        // Control loop related fields
+        status.setControlLoopId(controlLoopId);
+        status.setControlLoops(participantHandler.getControlLoopHandler().getControlLoops());
+        status.setResponse(response);
+
+        publisher.send(status);
+    }
+
+    /**
+     * Makes a new timer pool.
+     *
+     * @return a new timer pool
+     */
+    protected ScheduledExecutorService makeTimerPool() {
+        return Executors.newScheduledThreadPool(1);
+    }
+}
diff --git a/tosca-controlloop/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/comm/ParticipantStatusPublisher.java b/tosca-controlloop/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/comm/ParticipantStatusPublisher.java
new file mode 100644
index 000000000..e909327cd
--- /dev/null
+++ b/tosca-controlloop/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/comm/ParticipantStatusPublisher.java
@@ -0,0 +1,62 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2021 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.clamp.controlloop.participant.intermediary.comm;
+
+import java.io.Closeable;
+import java.util.List;
+import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantStatus;
+import org.onap.policy.common.endpoints.event.comm.TopicSink;
+import org.onap.policy.common.endpoints.event.comm.client.TopicSinkClient;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * This class is used to send Participant Status messages to clamp using TopicSinkClient.
+ */
+public class ParticipantStatusPublisher implements Closeable {
+    private static final Logger LOGGER = LoggerFactory.getLogger(ParticipantStatusPublisher.class);
+
+    private final TopicSinkClient topicSinkClient;
+
+    /**
+     * Constructor for instantiating ParticipantStatusPublisher.
+     *
+     * @param topicSinks the topic sinks
+     */
+    public ParticipantStatusPublisher(List<TopicSink> topicSinks) {
+        this.topicSinkClient = new TopicSinkClient(topicSinks.get(0));
+    }
+
+    /**
+     * Method to send Participant Status message to clamp on demand.
+     *
+     * @param participantStatus the Participant Status
+     */
+    public void send(final ParticipantStatus participantStatus) {
+        topicSinkClient.send(participantStatus);
+        LOGGER.debug("Sent Participant Status message to CLAMP - {}", participantStatus);
+    }
+
+    @Override
+    public void close() {
+        // No explicit action on this class
+    }
+}
diff --git a/tosca-controlloop/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/handler/ControlLoopHandler.java b/tosca-controlloop/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/handler/ControlLoopHandler.java
new file mode 100644
index 000000000..f27be961b
--- /dev/null
+++ b/tosca-controlloop/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/handler/ControlLoopHandler.java
@@ -0,0 +1,282 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2021 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.clamp.controlloop.participant.intermediary.handler;
+
+import java.io.Closeable;
+import java.util.ArrayList;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.UUID;
+import org.apache.commons.collections4.CollectionUtils;
+import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ClElementStatistics;
+import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ControlLoop;
+import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ControlLoopElement;
+import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ControlLoopOrderedState;
+import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ControlLoopState;
+import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ControlLoops;
+import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantControlLoopStateChange;
+import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantControlLoopUpdate;
+import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantResponseDetails;
+import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantResponseStatus;
+import org.onap.policy.clamp.controlloop.participant.intermediary.comm.MessageSender;
+import org.onap.policy.clamp.controlloop.participant.intermediary.parameters.ParticipantIntermediaryParameters;
+import org.onap.policy.models.tosca.authorative.concepts.ToscaConceptIdentifier;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/*
+ * This class is responsible for managing the state of all control loops in the participant.
+ */
+public class ControlLoopHandler implements Closeable {
+    private static final Logger LOGGER = LoggerFactory.getLogger(ControlLoopHandler.class);
+
+    private ToscaConceptIdentifier participantId = null;
+    private MessageSender sender = null;
+
+    private final Map<ToscaConceptIdentifier, ControlLoop> controlLoopMap = new LinkedHashMap<>();
+    private final Map<UUID, ControlLoopElement> elementsOnThisParticipant = new LinkedHashMap<>();
+
+    public ControlLoopHandler() {
+    }
+
+    /**
+     * Constructor, set the participant ID and sender.
+     *
+     * @param parameters the parameters of the participant
+     * @param sender the sender for sending responses to messages
+     */
+    public ControlLoopHandler(ParticipantIntermediaryParameters parameters, MessageSender sender) {
+        this.participantId = parameters.getParticipantId();
+        this.sender = sender;
+    }
+
+    @Override
+    public void close() {
+        // No explicit action on this class
+    }
+
+    /**
+     * Handle a control loop element state change message.
+     *
+     * @param id controlloop element id
+     * @param state the updated state
+     * @return controlLoopElement the updated controlloop element
+     */
+    public ControlLoopElement updateControlLoopElementState(UUID id, ControlLoopOrderedState state) {
+
+        if (id == null) {
+            return null;
+        }
+
+        ControlLoopElement clElement = elementsOnThisParticipant.get(id);
+        if (clElement != null) {
+            clElement.setOrderedState(state);
+            LOGGER.debug("Control loop element {} ordered state changed to {}", id, state);
+            ParticipantResponseDetails response = new ParticipantResponseDetails();
+            sender.sendResponse(response);
+            return elementsOnThisParticipant.get(id);
+        }
+
+        return null;
+    }
+
+    public void updateControlLoopElementStatistics(ClElementStatistics elementStatistics) {
+        // TODO Handle statistics coming from a participant implementation
+    }
+
+    /**
+     * Handle a control loop state change message.
+     *
+     * @param definition controlloop id
+     * @param state the updated state
+     * @return controlLoop the updated controlloop
+     */
+    public ControlLoop updateControlLoopState(ToscaConceptIdentifier definition, ControlLoopOrderedState state) {
+        if (definition == null) {
+            return null;
+        }
+
+        ControlLoop controlLoop = controlLoopMap.get(definition);
+        if (controlLoop == null) {
+            LOGGER.debug("Control loop {} does not use this participant", definition.getName());
+            return null;
+        }
+
+        ParticipantResponseDetails response = new ParticipantResponseDetails();
+        handleState(controlLoop, response, state);
+        sender.sendResponse(response);
+        return controlLoop;
+    }
+
+    /**
+     * Handle a control loop state change message.
+     *
+     * @param stateChangeMsg the state change message
+     */
+    public void handleControlLoopStateChange(ParticipantControlLoopStateChange stateChangeMsg) {
+        if (stateChangeMsg.getControlLoopId() == null) {
+            return;
+        }
+
+        ControlLoop controlLoop = controlLoopMap.get(stateChangeMsg.getControlLoopId());
+
+        if (controlLoop == null) {
+            LOGGER.debug("Control loop {} does not use this participant", stateChangeMsg.getControlLoopId());
+            return;
+        }
+
+        ParticipantResponseDetails response = new ParticipantResponseDetails(stateChangeMsg);
+        handleState(controlLoop, response, stateChangeMsg.getOrderedState());
+        sender.sendResponse(response);
+    }
+
+    /**
+     * Method to handle state changes.
+     *
+     * @param controlLoop participant response
+     * @param response participant response
+     * @param state controlloop ordered state
+     */
+    private void handleState(final ControlLoop controlLoop, final ParticipantResponseDetails response,
+            ControlLoopOrderedState state) {
+        switch (state) {
+            case UNINITIALISED:
+                handleUninitialisedState(controlLoop, response);
+                break;
+            case PASSIVE:
+                handlePassiveState(controlLoop, response);
+                break;
+            case RUNNING:
+                handleRunningState(controlLoop, response);
+                break;
+            default:
+                LOGGER.debug("StateChange message has no state, state is null {}", controlLoop.getDefinition());
+                break;
+        }
+    }
+
+    /**
+     * Handle a control loop update message.
+     *
+     * @param updateMsg the update message
+     */
+    public void handleControlLoopUpdate(ParticipantControlLoopUpdate updateMsg) {
+        if (!updateMsg.appliesTo(participantId)) {
+            return;
+        }
+
+        ControlLoop controlLoop = controlLoopMap.get(updateMsg.getControlLoopId());
+
+        ParticipantResponseDetails response = new ParticipantResponseDetails(updateMsg);
+
+        // TODO: Updates to existing ControlLoops are not supported yet (Addition/Removal of ControlLoop
+        // elements to existing ControlLoop has to be supported).
+        if (controlLoop != null) {
+            response.setResponseStatus(ParticipantResponseStatus.FAIL);
+            response.setResponseMessage("Control loop " + updateMsg.getControlLoopId()
+                    + " already defined on participant " + participantId);
+
+            sender.sendResponse(response);
+            return;
+        }
+
+        controlLoop = updateMsg.getControlLoop();
+        controlLoop.getElements().removeIf(element -> participantId.equals(element.getParticipantId()));
+
+        controlLoopMap.put(updateMsg.getControlLoopId(), controlLoop);
+        for (ControlLoopElement element : updateMsg.getControlLoop().getElements()) {
+            element.setState(element.getOrderedState().asState());
+            elementsOnThisParticipant.put(element.getId(), element);
+        }
+
+        response.setResponseStatus(ParticipantResponseStatus.SUCCESS);
+        response.setResponseMessage(
+                "Control loop " + updateMsg.getControlLoopId() + " defined on participant " + participantId);
+
+        sender.sendResponse(response);
+    }
+
+    /**
+     * Method to handle when the new state from participant is UNINITIALISED state.
+     *
+     * @param controlLoop participant response
+     * @param response participant response
+     */
+    private void handleUninitialisedState(final ControlLoop controlLoop, final ParticipantResponseDetails response) {
+        handleStateChange(controlLoop, ControlLoopState.UNINITIALISED, response);
+        controlLoopMap.remove(controlLoop.getKey().asIdentifier());
+    }
+
+    /**
+     * Method to handle when the new state from participant is PASSIVE state.
+     *
+     * @param controlLoop participant response
+     * @param response participant response
+     */
+    private void handlePassiveState(final ControlLoop controlLoop, final ParticipantResponseDetails response) {
+        handleStateChange(controlLoop, ControlLoopState.PASSIVE, response);
+    }
+
+    /**
+     * Method to handle when the new state from participant is RUNNING state.
+     *
+     * @param controlLoop participant response
+     * @param response participant response
+     */
+    private void handleRunningState(final ControlLoop controlLoop, final ParticipantResponseDetails response) {
+        handleStateChange(controlLoop, ControlLoopState.RUNNING, response);
+    }
+
+    /**
+     * Method to update the state of control loop elements.
+     *
+     * @param controlLoop participant status in memory
+     * @param state new state of the control loop elements
+     */
+    private void handleStateChange(ControlLoop controlLoop, ControlLoopState newState,
+            ParticipantResponseDetails response) {
+
+        if (newState.equals(controlLoop.getState())) {
+            response.setResponseStatus(ParticipantResponseStatus.SUCCESS);
+            response.setResponseMessage("Control loop is already in state " + newState);
+            return;
+        }
+
+        if (!CollectionUtils.isEmpty(controlLoop.getElements())) {
+            controlLoop.getElements().forEach(element -> element.setState(newState));
+        }
+
+        response.setResponseStatus(ParticipantResponseStatus.SUCCESS);
+        response.setResponseMessage("ControlLoop state changed from " + controlLoop.getState() + " to " + newState);
+        controlLoop.setState(newState);
+    }
+
+    /**
+     * Get control loops as a {@link ConrolLoops} class.
+     *
+     * @return the control loops
+     */
+    public ControlLoops getControlLoops() {
+        ControlLoops controlLoops = new ControlLoops();
+        controlLoops.setControlLoopList(new ArrayList<>(controlLoopMap.values()));
+        return controlLoops;
+    }
+}
diff --git a/tosca-controlloop/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/handler/IntermediaryActivator.java b/tosca-controlloop/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/handler/IntermediaryActivator.java
new file mode 100644
index 000000000..dd0cf30a8
--- /dev/null
+++ b/tosca-controlloop/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/handler/IntermediaryActivator.java
@@ -0,0 +1,129 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2021 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.clamp.controlloop.participant.intermediary.handler;
+
+import java.util.List;
+import java.util.concurrent.atomic.AtomicReference;
+import javax.ws.rs.core.Response.Status;
+import lombok.Getter;
+import lombok.experimental.Delegate;
+import org.onap.policy.clamp.controlloop.common.exception.ControlLoopRuntimeException;
+import org.onap.policy.clamp.controlloop.participant.intermediary.comm.ControlLoopUpdateListener;
+import org.onap.policy.clamp.controlloop.participant.intermediary.comm.ParticipantStatusPublisher;
+import org.onap.policy.clamp.controlloop.participant.intermediary.parameters.ParticipantIntermediaryParameters;
+import org.onap.policy.common.endpoints.event.comm.TopicEndpointManager;
+import org.onap.policy.common.endpoints.event.comm.TopicSink;
+import org.onap.policy.common.endpoints.event.comm.TopicSource;
+import org.onap.policy.common.endpoints.listeners.MessageTypeDispatcher;
+import org.onap.policy.common.utils.services.ServiceManagerContainer;
+
+/**
+ * This class activates the Participant Intermediary together with all its handlers.
+ */
+public class IntermediaryActivator extends ServiceManagerContainer {
+    // Name of the message type for messages on topics
+    private static final String[] MSG_TYPE_NAMES = {"messageType"};
+
+    @Getter
+    private final ParticipantIntermediaryParameters parameters;
+
+    // Topics from which the participant receives and to which the participant sends messages
+    private List<TopicSink> topicSinks;
+    private List<TopicSource> topicSources;
+
+    // The participant handler for this intermediary
+    final AtomicReference<ParticipantHandler> participantHandler = new AtomicReference<>();
+
+    /**
+     * Listens for messages on the topic, decodes them into a message, and then dispatches them.
+     */
+    private final MessageTypeDispatcher msgDispatcher;
+
+    /**
+     * Instantiate the activator for participant.
+     *
+     * @param parameters the parameters for the participant intermediary
+     */
+    public IntermediaryActivator(final ParticipantIntermediaryParameters parameters) {
+        this.parameters = parameters;
+
+        topicSinks =
+                TopicEndpointManager.getManager().addTopicSinks(parameters.getClampControlLoopTopics().getTopicSinks());
+
+        topicSources = TopicEndpointManager.getManager()
+                .addTopicSources(parameters.getClampControlLoopTopics().getTopicSources());
+
+        try {
+            this.msgDispatcher = new MessageTypeDispatcher(MSG_TYPE_NAMES);
+        } catch (final RuntimeException e) {
+            throw new ControlLoopRuntimeException(Status.INTERNAL_SERVER_ERROR,
+                    "topic message dispatcher failed to start", e);
+        }
+
+        // @formatter:off
+        final AtomicReference<ParticipantStatusPublisher>     statusPublisher                = new AtomicReference<>();
+        final AtomicReference<ControlLoopUpdateListener>      controlLoopUpdateListener      = new AtomicReference<>();
+
+        addAction("Topic endpoint management",
+            () -> TopicEndpointManager.getManager().start(),
+            () -> TopicEndpointManager.getManager().shutdown());
+
+        addAction("Participant Status Publisher",
+            () -> statusPublisher.set(new ParticipantStatusPublisher(topicSinks)),
+            () -> statusPublisher.get().close());
+
+        addAction("Participant Handler",
+            () -> participantHandler.set(new ParticipantHandler(parameters, statusPublisher.get())),
+            () -> participantHandler.get().close());
+
+        addAction("Control Loop Update Listener",
+            () -> controlLoopUpdateListener.set(new ControlLoopUpdateListener(participantHandler.get())),
+            () -> controlLoopUpdateListener.get().close());
+
+        addAction("Topic Message Dispatcher", this::registerMsgDispatcher, this::unregisterMsgDispatcher);
+        // @formatter:on
+    }
+
+    /**
+     * Registers the dispatcher with the topic source(s).
+     */
+    private void registerMsgDispatcher() {
+        for (final TopicSource source : topicSources) {
+            source.register(msgDispatcher);
+        }
+    }
+
+    /**
+     * Unregisters the dispatcher from the topic source(s).
+     */
+    private void unregisterMsgDispatcher() {
+        for (final TopicSource source : topicSources) {
+            source.unregister(msgDispatcher);
+        }
+    }
+
+    /**
+     * Return the participant handler.
+     */
+    public ParticipantHandler getParticipantHandler() {
+        return participantHandler.get();
+    }
+}
diff --git a/tosca-controlloop/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/handler/ParticipantHandler.java b/tosca-controlloop/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/handler/ParticipantHandler.java
new file mode 100644
index 000000000..1150471ae
--- /dev/null
+++ b/tosca-controlloop/participant/participant-intermediary/src/main/java/org/onap/policy/clamp/controlloop/participant/intermediary/handler/ParticipantHandler.java
@@ -0,0 +1,204 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2021 Nordix Foundation.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.clamp.controlloop.participant.intermediary.handler;
+
+import java.io.Closeable;
+import java.util.Objects;
+import lombok.Getter;
+import lombok.Setter;
+import org.onap.policy.clamp.controlloop.models.controlloop.concepts.Participant;
+import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ParticipantHealthStatus;
+import org.onap.policy.clamp.controlloop.models.controlloop.concepts.ParticipantState;
+import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantResponseDetails;
+import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantResponseStatus;
+import org.onap.policy.clamp.controlloop.models.messages.dmaap.participant.ParticipantStateChange;
+import org.onap.policy.clamp.controlloop.participant.intermediary.comm.MessageSender;
+import org.onap.policy.clamp.controlloop.participant.intermediary.comm.ParticipantStatusPublisher;
+import org.onap.policy.clamp.controlloop.participant.intermediary.parameters.ParticipantIntermediaryParameters;
+import org.onap.policy.models.tosca.authorative.concepts.ToscaConceptIdentifier;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * This class is responsible for managing the state of a participant.
+ */
+@Getter
+public class ParticipantHandler implements Closeable {
+    private static final Logger LOGGER = LoggerFactory.getLogger(ParticipantHandler.class);
+
+    private final ToscaConceptIdentifier participantId;
+    private final MessageSender sender;
+    private final ControlLoopHandler controlLoopHandler;
+
+    @Setter
+    private ParticipantState state = ParticipantState.UNKNOWN;
+
+    @Setter
+    private ParticipantHealthStatus healthStatus = ParticipantHealthStatus.UNKNOWN;
+
+    /**
+     * Constructor, set the participant ID and sender.
+     *
+     * @param parameters the parameters of the participant
+     * @param publisher the publisher for sending responses to messages
+     */
+    public ParticipantHandler(ParticipantIntermediaryParameters parameters, ParticipantStatusPublisher publisher) {
+        this.participantId = parameters.getParticipantId();
+        this.sender = new MessageSender(this, publisher, parameters.getReportingTimeInterval());
+        this.controlLoopHandler = new ControlLoopHandler(parameters, sender);
+    }
+
+    @Override
+    public void close() {
+        sender.close();
+        controlLoopHandler.close();
+    }
+
+    /**
+     * Method which handles a participant state change event from clamp.
+     *
+     * @param stateChangeMsg participant state change message
+     */
+    public void handleParticipantStateChange(final ParticipantStateChange stateChangeMsg) {
+
+        if (!stateChangeMsg.appliesTo(participantId)) {
+            return;
+        }
+
+        ParticipantResponseDetails response = new ParticipantResponseDetails(stateChangeMsg);
+
+        switch (stateChangeMsg.getState()) {
+            case PASSIVE:
+                handlePassiveState(response);
+                break;
+            case ACTIVE:
+                handleActiveState(response);
+                break;
+            case SAFE:
+                handleSafeState(response);
+                break;
+            case TEST:
+                handleTestState(response);
+                break;
+            case TERMINATED:
+                handleTerminatedState(response);
+                break;
+            default:
+                LOGGER.debug("StateChange message has no state, state is null {}", stateChangeMsg.getParticipantId());
+                response.setResponseStatus(ParticipantResponseStatus.FAIL);
+                response.setResponseMessage("StateChange message has invalid state for participantId "
+                    + stateChangeMsg.getParticipantId());
+                break;
+        }
+
+        sender.sendResponse(response);
+    }
+
+    /**
+     * Method to handle when the new state from participant is active.
+     *
+     * @param response participant response
+     */
+    private void handleActiveState(final ParticipantResponseDetails response) {
+        handleStateChange(ParticipantState.ACTIVE, response);
+    }
+
+    /**
+     * Method to handle when the new state from participant is passive.
+     *
+     * @param response participant response
+     */
+    private void handlePassiveState(final ParticipantResponseDetails response) {
+        handleStateChange(ParticipantState.PASSIVE, response);
+    }
+
+    /**
+     * Method to handle when the new state from participant is safe.
+     *
+     * @param response participant response
+     */
+    private void handleSafeState(final ParticipantResponseDetails response) {
+        handleStateChange(ParticipantState.SAFE, response);
+    }
+
+    /**
+     * Method to handle when the new state from participant is TEST.
+     *
+     * @param response participant response
+     */
+    private void handleTestState(final ParticipantResponseDetails response) {
+        handleStateChange(ParticipantState.TEST, response);
+    }
+
+    /**
+     * Method to handle when the new state from participant is Terminated.
+     *
+     * @param response participant response
+     */
+    private void handleTerminatedState(final ParticipantResponseDetails response) {
+        handleStateChange(ParticipantState.TERMINATED, response);
+    }
+
+    private void handleStateChange(ParticipantState newParticipantState, ParticipantResponseDetails response) {
+        if (state.equals(newParticipantState)) {
+            response.setResponseStatus(ParticipantResponseStatus.SUCCESS);
+            response.setResponseMessage("Participant already in state " + newParticipantState);
+        } else {
+            response.setResponseStatus(ParticipantResponseStatus.SUCCESS);
+            response.setResponseMessage("Participant state changed from " + state + " to " + newParticipantState);
+            state = newParticipantState;
+        }
+    }
+
+    /**
+     * Method to update participant state.
+     *
+     * @param definition participant definition
+     * @param participantState participant state
+     */
+    public Participant updateParticipantState(ToscaConceptIdentifier definition,
+            ParticipantState participantState) {
+        if (!Objects.equals(definition, participantId)) {
+            LOGGER.debug("No participant with this ID {}", definition.getName());
+            return null;
+        }
+        ParticipantResponseDetails response = new ParticipantResponseDetails();
+        handleStateChange(participantState, response);
+        sender.sendResponse(response);
+        return getParticipant(definition.getName(), definition.getVersion());
+    }
+
+    /**
+     * Get participants as a {@link Participant} class.
+     *
+     * @return the participant
+     */
+    public Participant getParticipant(String name, String version) {
+        if (participantId.getName().equals(name)) {
+            Participant participant = new Participant();
+            participant.setDefinition(participantId);
+            participant.setParticipantState(state);
+            participant.setHealthStatus(healthStatus);
+            return participant;
+        }
+        return null;
+    }
+}