Rename L2 load balancer to port load balancer

CLI commands are also renamed to plbs, plb-add and plb-remove

Change-Id: I4c26b390acc5a961594a1dca92a76bee2148c090
diff --git a/apps/portloadbalancer/BUILD b/apps/portloadbalancer/BUILD
new file mode 100644
index 0000000..3b5301e
--- /dev/null
+++ b/apps/portloadbalancer/BUILD
@@ -0,0 +1,19 @@
+COMPILE_DEPS = CORE_DEPS + KRYO + CLI + [
+    "//core/store/serializers:onos-core-serializers",
+]
+
+TEST_DEPS = TEST_ADAPTERS
+
+osgi_jar_with_tests(
+    karaf_command_packages = ["org.onosproject.portloadbalancer.cli"],
+    test_deps = TEST_DEPS,
+    deps = COMPILE_DEPS,
+)
+
+onos_app(
+    app_name = "org.onosproject.portloadbalancer",
+    category = "Utilities",
+    description = "Port Load Balance Service",
+    title = "Port Load Balance Service",
+    url = "http://onosproject.org",
+)
diff --git a/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/api/PortLoadBalancer.java b/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/api/PortLoadBalancer.java
new file mode 100644
index 0000000..6cd8df1
--- /dev/null
+++ b/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/api/PortLoadBalancer.java
@@ -0,0 +1,110 @@
+/*
+ * Copyright 2018-present Open Networking 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.
+ */
+package org.onosproject.portloadbalancer.api;
+
+import org.onosproject.net.PortNumber;
+
+import java.util.Objects;
+import java.util.Set;
+
+import static com.google.common.base.MoreObjects.toStringHelper;
+
+/**
+ * Represents port load balancer information.
+ */
+public class PortLoadBalancer {
+    private PortLoadBalancerId portLoadBalancerId;
+    private Set<PortNumber> ports;
+    private PortLoadBalancerMode mode;
+
+    /**
+     * Constructs a port load balancer.
+     *
+     * @param portLoadBalancerId port load balancer ID
+     * @param ports Set of member ports
+     * @param mode port load balancer mode
+     */
+    public PortLoadBalancer(PortLoadBalancerId portLoadBalancerId, Set<PortNumber> ports, PortLoadBalancerMode mode) {
+        this.portLoadBalancerId = portLoadBalancerId;
+        this.ports = ports;
+        this.mode = mode;
+    }
+
+    /**
+     * Gets port load balancer ID.
+     *
+     * @return port load balancer ID
+     */
+    public PortLoadBalancerId portLoadBalancerId() {
+        return portLoadBalancerId;
+    }
+
+    /**
+     * Gets set of member ports.
+     *
+     * @return Set of member ports
+     */
+    public Set<PortNumber> ports() {
+        return ports;
+    }
+
+    /**
+     * Gets port load balancer mode.
+     *
+     * @return port load balancer mode.
+     */
+    public PortLoadBalancerMode mode() {
+        return mode;
+    }
+
+    /**
+     * Gets port load balancer data.
+     *
+     * @return port load balancer data
+     */
+    public PortLoadBalancerData data() {
+        return new PortLoadBalancerData(portLoadBalancerId);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(portLoadBalancerId, ports, mode);
+    }
+
+    @Override
+    public boolean equals(final Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (!(obj instanceof PortLoadBalancer)) {
+            return false;
+        }
+        final PortLoadBalancer other = (PortLoadBalancer) obj;
+
+        return Objects.equals(this.portLoadBalancerId, other.portLoadBalancerId) &&
+                Objects.equals(this.ports, other.ports) &&
+                this.mode == other.mode;
+    }
+
+    @Override
+    public String toString() {
+        return toStringHelper(getClass())
+                .add("id", portLoadBalancerId)
+                .add("ports", ports)
+                .add("mode", mode)
+                .toString();
+    }
+}
diff --git a/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/api/PortLoadBalancerAdminService.java b/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/api/PortLoadBalancerAdminService.java
new file mode 100644
index 0000000..2a2ef20
--- /dev/null
+++ b/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/api/PortLoadBalancerAdminService.java
@@ -0,0 +1,45 @@
+/*
+ * Copyright 2018-present Open Networking 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.
+ */
+package org.onosproject.portloadbalancer.api;
+
+import org.onosproject.net.PortNumber;
+
+import java.util.Set;
+
+/**
+ * Port load balancer admin service.
+ */
+public interface PortLoadBalancerAdminService {
+    /**
+     * Creates or updates a port load balancer.
+     *
+     * @param portLoadBalancerId port load balancer id
+     * @param ports physical ports in the port load balancer
+     * @param mode port load balancer mode
+     * @return port load balancer that is created or updated
+     */
+    PortLoadBalancer createOrUpdate(PortLoadBalancerId portLoadBalancerId, Set<PortNumber> ports,
+                                    PortLoadBalancerMode mode);
+
+    /**
+     * Removes a port load balancer.
+     *
+     * @param portLoadBalancerId port load balancer id
+     * @return port load balancer that is removed or null if it was not possible
+     */
+    PortLoadBalancer remove(PortLoadBalancerId portLoadBalancerId);
+
+}
diff --git a/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/api/PortLoadBalancerData.java b/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/api/PortLoadBalancerData.java
new file mode 100644
index 0000000..7d1e93d
--- /dev/null
+++ b/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/api/PortLoadBalancerData.java
@@ -0,0 +1,106 @@
+/*
+ * Copyright 2018-present Open Networking 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.
+ */
+package org.onosproject.portloadbalancer.api;
+
+
+import java.util.Objects;
+
+import static com.google.common.base.MoreObjects.toStringHelper;
+
+/**
+ * Represents port load balancer event data.
+ */
+public class PortLoadBalancerData {
+
+    // We exchange only id and nextid in the events
+    private PortLoadBalancerId portLoadBalancerId;
+    private int nextId;
+
+    /**
+     * Constructs a port load balancer data.
+     *
+     * @param portLoadBalancerId port load balancer ID
+     */
+    public PortLoadBalancerData(PortLoadBalancerId portLoadBalancerId) {
+        this.portLoadBalancerId = portLoadBalancerId;
+        this.nextId = -1;
+    }
+
+    /**
+     * Constructs a port load balancer data.
+     *
+     * @param portLoadBalancerId port load balancer ID
+     * @param nextId port load balancer next id
+     */
+    public PortLoadBalancerData(PortLoadBalancerId portLoadBalancerId, int nextId) {
+        this.portLoadBalancerId = portLoadBalancerId;
+        this.nextId = nextId;
+    }
+
+    /**
+     * Gets port load balancer ID.
+     *
+     * @return port load balancer ID
+     */
+    public PortLoadBalancerId portLoadBalancerId() {
+        return portLoadBalancerId;
+    }
+
+    /**
+     * Gets port load balancer next id.
+     *
+     * @return port load balancer next id
+     */
+    public int nextId() {
+        return nextId;
+    }
+
+    /**
+     * Sets port load balancer next id.
+     *
+     * @param nextId port load balancer next id
+     */
+    public void setNextId(int nextId) {
+        this.nextId = nextId;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(portLoadBalancerId, nextId);
+    }
+
+    @Override
+    public boolean equals(final Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (!(obj instanceof PortLoadBalancerData)) {
+            return false;
+        }
+        final PortLoadBalancerData other = (PortLoadBalancerData) obj;
+
+        return Objects.equals(this.portLoadBalancerId, other.portLoadBalancerId) &&
+                this.nextId == other.nextId;
+    }
+
+    @Override
+    public String toString() {
+        return toStringHelper(getClass())
+                .add("portLoadBalancerId", portLoadBalancerId)
+                .add("nextId", nextId)
+                .toString();
+    }
+}
diff --git a/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/api/PortLoadBalancerEvent.java b/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/api/PortLoadBalancerEvent.java
new file mode 100644
index 0000000..bd9c234
--- /dev/null
+++ b/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/api/PortLoadBalancerEvent.java
@@ -0,0 +1,119 @@
+/*
+ * Copyright 2018-present Open Networking 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.
+ */
+
+package org.onosproject.portloadbalancer.api;
+
+import org.onlab.util.Tools;
+import org.onosproject.event.AbstractEvent;
+import java.util.Objects;
+
+import static com.google.common.base.MoreObjects.toStringHelper;
+
+/**
+ * Port load balancer event.
+ */
+public class PortLoadBalancerEvent extends AbstractEvent<PortLoadBalancerEvent.Type, PortLoadBalancerData> {
+
+    private PortLoadBalancerData prevSubject;
+
+    /**
+     * Port load balancer event type.
+     */
+    public enum Type {
+        /**
+         * Port load balancer creation is requested.
+         */
+        ADDED,
+
+        /**
+         * Port load balancer deletion is requested.
+         */
+        REMOVED,
+
+        /**
+         * Port load balancer update is requested.
+         * E.g. member change.
+         */
+        UPDATED,
+
+        /**
+         * Port load balancer creation/update is completed successfully.
+         */
+        INSTALLED,
+
+        /**
+         * Port load balancer deletion is completed successfully.
+         */
+        UNINSTALLED,
+
+        /**
+         * Error occurs during creation/update/deletion of a port load balancer.
+         */
+        FAILED
+    }
+
+    /**
+     * Constructs a port load balancer event.
+     *
+     * @param type event type
+     * @param subject current port load balancer information
+     * @param prevSubject previous port load balancer information
+     */
+    public PortLoadBalancerEvent(Type type, PortLoadBalancerData subject, PortLoadBalancerData prevSubject) {
+        super(type, subject);
+        this.prevSubject = prevSubject;
+    }
+
+    /**
+     * Gets previous port load balancer information.
+     *
+     * @return previous subject
+     */
+    public PortLoadBalancerData prevSubject() {
+        return prevSubject;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(subject(), time(), prevSubject);
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        if (this == other) {
+            return true;
+        }
+
+        if (!(other instanceof PortLoadBalancerEvent)) {
+            return false;
+        }
+
+        PortLoadBalancerEvent that = (PortLoadBalancerEvent) other;
+        return Objects.equals(this.subject(), that.subject()) &&
+                Objects.equals(this.type(), that.type()) &&
+                Objects.equals(this.prevSubject, that.prevSubject);
+    }
+
+    @Override
+    public String toString() {
+        return toStringHelper(this)
+                .add("type", type())
+                .add("subject", subject())
+                .add("prevSubject", prevSubject)
+                .add("time", Tools.defaultOffsetDataTime(time()))
+                .toString();
+    }
+}
diff --git a/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/api/PortLoadBalancerId.java b/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/api/PortLoadBalancerId.java
new file mode 100644
index 0000000..a102dd5
--- /dev/null
+++ b/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/api/PortLoadBalancerId.java
@@ -0,0 +1,87 @@
+/*
+ * Copyright 2018-present Open Networking 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.
+ */
+package org.onosproject.portloadbalancer.api;
+
+import org.onosproject.net.DeviceId;
+
+import java.util.Objects;
+
+/**
+ * Port load balancer identifier.
+ * It is used to identify a load balancer across the entire system and therefore has to be unique system-wide.
+ */
+public class PortLoadBalancerId {
+    private final DeviceId deviceId;
+
+    /**
+     * Port load balancer key.
+     * It is used to identify a load balancer on a specific device and therefore has to be unique device-wide.
+     */
+    private final int key;
+
+    /**
+     * Constructs port load balancer ID.
+     *
+     * @param deviceId device ID
+     * @param key port load balancer key
+     */
+    public PortLoadBalancerId(DeviceId deviceId, int key) {
+        this.deviceId = deviceId;
+        this.key = key;
+    }
+
+    /**
+     * Returns port load balancer device ID.
+     *
+     * @return port load balancer device ID
+     */
+    public DeviceId deviceId() {
+        return deviceId;
+    }
+
+    /**
+     * Returns port load balancer key.
+     *
+     * @return port load balancer key
+     */
+    public int key() {
+        return key;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(deviceId, key);
+    }
+
+    @Override
+    public boolean equals(final Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (!(obj instanceof PortLoadBalancerId)) {
+            return false;
+        }
+        final PortLoadBalancerId other = (PortLoadBalancerId) obj;
+
+        return Objects.equals(this.deviceId, other.deviceId) &&
+                Objects.equals(this.key, other.key);
+    }
+
+    @Override
+    public String toString() {
+        return deviceId.toString() + ":" + key;
+    }
+}
diff --git a/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/api/PortLoadBalancerListener.java b/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/api/PortLoadBalancerListener.java
new file mode 100644
index 0000000..de4efa8
--- /dev/null
+++ b/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/api/PortLoadBalancerListener.java
@@ -0,0 +1,25 @@
+/*
+ * Copyright 2018-present Open Networking 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.
+ */
+
+package org.onosproject.portloadbalancer.api;
+
+import org.onosproject.event.EventListener;
+
+/**
+ * Port load balancer event listener.
+ */
+public interface PortLoadBalancerListener extends EventListener<PortLoadBalancerEvent> {
+}
diff --git a/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/api/PortLoadBalancerMode.java b/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/api/PortLoadBalancerMode.java
new file mode 100644
index 0000000..233c116
--- /dev/null
+++ b/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/api/PortLoadBalancerMode.java
@@ -0,0 +1,36 @@
+/*
+ * Copyright 2018-present Open Networking 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.
+ */
+package org.onosproject.portloadbalancer.api;
+
+/**
+ * Port load balancer mode.
+ */
+public enum PortLoadBalancerMode {
+    /**
+     * Static port load balancer.
+     *
+     * In STATIC mode, all member ports of this load balancer will be used to transmit data as long as it is enabled.
+     */
+    STATIC,
+
+    /**
+     * Port load balancer based on LACP.
+     *
+     * In LACP mode, we decide whether to use a member port to transmit data or not according to
+     * the LACP negotiation result.
+     */
+    LACP
+}
diff --git a/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/api/PortLoadBalancerService.java b/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/api/PortLoadBalancerService.java
new file mode 100644
index 0000000..5c7f1d3
--- /dev/null
+++ b/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/api/PortLoadBalancerService.java
@@ -0,0 +1,97 @@
+/*
+ * Copyright 2018-present Open Networking 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.
+ */
+
+package org.onosproject.portloadbalancer.api;
+
+import org.onosproject.core.ApplicationId;
+import org.onosproject.event.ListenerService;
+
+import java.util.Map;
+
+/**
+ * Port load balance service.
+ */
+public interface PortLoadBalancerService extends ListenerService<PortLoadBalancerEvent, PortLoadBalancerListener> {
+    /**
+     * Gets all port load balancers from the store.
+     *
+     * @return port load balancer ID and port load balancer information mapping
+     */
+    Map<PortLoadBalancerId, PortLoadBalancer> getPortLoadBalancers();
+
+    /**
+     * Gets port load balancer that matches given device ID and key, or null if not found.
+     *
+     * @param portLoadBalancerId port load balancer id
+     * @return port load balancer information
+     */
+    PortLoadBalancer getPortLoadBalancer(PortLoadBalancerId portLoadBalancerId);
+
+    /**
+     * Gets the mapping between port load balancer id and
+     * the next objective id that represents the port load balancer.
+     *
+     * @return port load balancer id and next id mapping
+     */
+    Map<PortLoadBalancerId, Integer> getPortLoadBalancerNexts();
+
+    /**
+     * Gets port load balancer next id that matches given device Id and key, or null if not found.
+     *
+     * @param portLoadBalancerId port load balancer id
+     * @return next ID
+     */
+    int getPortLoadBalancerNext(PortLoadBalancerId portLoadBalancerId);
+
+    /**
+     * Reserves a port load balancer. Only one application
+     * at time can reserve a given port load balancer.
+     *
+     * @param portLoadBalancerId the port load balancer id
+     * @param appId the application id
+     * @return true if reservation was successful false otherwise
+     */
+    boolean reserve(PortLoadBalancerId portLoadBalancerId, ApplicationId appId);
+
+    /**
+     * Releases a port load balancer. Once released
+     * by the owner the port load balancer is eligible
+     * for removal.
+     *
+     * @param portLoadBalancerId the port load balancer id
+     * @param appId the application id
+     * @return true if release was successful false otherwise
+     */
+    boolean release(PortLoadBalancerId portLoadBalancerId, ApplicationId appId);
+
+    /**
+     * Gets reservation of a port load balancer. Only one application
+     * at time can reserve a given port load balancer.
+     *
+     * @param portLoadBalancerId the port load balancer id
+     * @return the id of the application using the port load balancer
+     */
+    ApplicationId getReservation(PortLoadBalancerId portLoadBalancerId);
+
+    /**
+     * Gets port load balancer reservations. Only one application
+     * at time can reserve a given port load balancer.
+     *
+     * @return reservations of the port load balancer resources
+     */
+    Map<PortLoadBalancerId, ApplicationId> getReservations();
+
+}
diff --git a/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/api/package-info.java b/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/api/package-info.java
new file mode 100644
index 0000000..63a0bf0
--- /dev/null
+++ b/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/api/package-info.java
@@ -0,0 +1,20 @@
+/*
+ * Copyright 2018-present Open Networking 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.
+ */
+
+/**
+ * Port load balancer API.
+ */
+package org.onosproject.portloadbalancer.api;
\ No newline at end of file
diff --git a/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/app/PortLoadBalancerManager.java b/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/app/PortLoadBalancerManager.java
new file mode 100644
index 0000000..ed59699
--- /dev/null
+++ b/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/app/PortLoadBalancerManager.java
@@ -0,0 +1,633 @@
+/*
+ * Copyright 2018-present Open Networking 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.
+ */
+
+package org.onosproject.portloadbalancer.app;
+
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.Sets;
+import org.osgi.service.component.annotations.Activate;
+import org.osgi.service.component.annotations.Component;
+import org.osgi.service.component.annotations.Deactivate;
+import org.osgi.service.component.annotations.Reference;
+import org.osgi.service.component.annotations.ReferenceCardinality;
+import org.onlab.util.KryoNamespace;
+import org.onosproject.cluster.ClusterService;
+import org.onosproject.cluster.LeadershipService;
+import org.onosproject.cluster.NodeId;
+import org.onosproject.core.ApplicationId;
+import org.onosproject.core.CoreService;
+import org.onosproject.portloadbalancer.api.PortLoadBalancer;
+import org.onosproject.portloadbalancer.api.PortLoadBalancerData;
+import org.onosproject.portloadbalancer.api.PortLoadBalancerEvent;
+import org.onosproject.portloadbalancer.api.PortLoadBalancerAdminService;
+import org.onosproject.portloadbalancer.api.PortLoadBalancerId;
+import org.onosproject.portloadbalancer.api.PortLoadBalancerListener;
+import org.onosproject.portloadbalancer.api.PortLoadBalancerMode;
+import org.onosproject.portloadbalancer.api.PortLoadBalancerService;
+import org.onosproject.mastership.MastershipService;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.PortNumber;
+import org.onosproject.net.device.DeviceEvent;
+import org.onosproject.net.device.DeviceListener;
+import org.onosproject.net.device.DeviceService;
+import org.onosproject.net.flow.DefaultTrafficSelector;
+import org.onosproject.net.flow.DefaultTrafficTreatment;
+import org.onosproject.net.flow.TrafficSelector;
+import org.onosproject.net.flow.TrafficTreatment;
+import org.onosproject.net.flow.instructions.Instruction;
+import org.onosproject.net.flow.instructions.Instructions;
+import org.onosproject.net.flowobjective.DefaultNextObjective;
+import org.onosproject.net.flowobjective.DefaultNextTreatment;
+import org.onosproject.net.flowobjective.FlowObjectiveService;
+import org.onosproject.net.flowobjective.NextObjective;
+import org.onosproject.net.flowobjective.Objective;
+import org.onosproject.net.flowobjective.ObjectiveContext;
+import org.onosproject.net.flowobjective.ObjectiveError;
+import org.onosproject.store.serializers.KryoNamespaces;
+import org.onosproject.store.service.ConsistentMap;
+import org.onosproject.store.service.MapEvent;
+import org.onosproject.store.service.MapEventListener;
+import org.onosproject.store.service.Serializer;
+import org.onosproject.store.service.StorageService;
+import org.onosproject.store.service.Versioned;
+import org.slf4j.Logger;
+
+import java.util.Collection;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.stream.Collectors;
+
+import static org.onlab.util.Tools.groupedThreads;
+import static org.slf4j.LoggerFactory.getLogger;
+
+@Component(
+        immediate = true,
+        service = { PortLoadBalancerService.class, PortLoadBalancerAdminService.class }
+)
+public class PortLoadBalancerManager implements PortLoadBalancerService, PortLoadBalancerAdminService {
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY)
+    private CoreService coreService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY)
+    private StorageService storageService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY)
+    private FlowObjectiveService flowObjService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY)
+    private MastershipService mastershipService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY)
+    private LeadershipService leadershipService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY)
+    private ClusterService clusterService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY)
+    private DeviceService deviceService;
+
+    private static final Logger log = getLogger(PortLoadBalancerManager.class);
+    private static final String APP_NAME = "org.onosproject.portloadbalancer";
+
+    private ApplicationId appId;
+    private ConsistentMap<PortLoadBalancerId, PortLoadBalancer> portLoadBalancerStore;
+    private ConsistentMap<PortLoadBalancerId, Integer> portLoadBalancerNextStore;
+    // TODO Evaluate if ResourceService is a better option
+    private ConsistentMap<PortLoadBalancerId, ApplicationId> portLoadBalancerResStore;
+    private Set<PortLoadBalancerListener> listeners = Sets.newConcurrentHashSet();
+
+    private ExecutorService portLoadBalancerEventExecutor;
+    private ExecutorService portLoadBalancerProvExecutor;
+    private ExecutorService deviceEventExecutor;
+
+    private MapEventListener<PortLoadBalancerId, PortLoadBalancer> portLoadBalancerStoreListener;
+    // TODO build CLI to view and clear the next store
+    private MapEventListener<PortLoadBalancerId, Integer> portLoadBalancerNextStoreListener;
+    private MapEventListener<PortLoadBalancerId, ApplicationId> portLoadBalancerResStoreListener;
+    private final DeviceListener deviceListener = new InternalDeviceListener();
+
+    @Activate
+    public void activate() {
+        appId = coreService.registerApplication(APP_NAME);
+
+        portLoadBalancerEventExecutor = Executors.newSingleThreadExecutor(
+                groupedThreads("portloadbalancer-event", "%d", log));
+        portLoadBalancerProvExecutor = Executors.newSingleThreadExecutor(
+                groupedThreads("portloadbalancer-prov", "%d", log));
+        deviceEventExecutor = Executors.newSingleThreadScheduledExecutor(
+                groupedThreads("portloadbalancer-dev-event", "%d", log));
+        portLoadBalancerStoreListener = new PortLoadBalancerStoreListener();
+        portLoadBalancerNextStoreListener = new PortLoadBalancerNextStoreListener();
+        portLoadBalancerResStoreListener = new PortLoadBalancerResStoreListener();
+
+        KryoNamespace serializer = KryoNamespace.newBuilder()
+                .register(KryoNamespaces.API)
+                .register(PortLoadBalancer.class)
+                .register(PortLoadBalancerId.class)
+                .register(PortLoadBalancerMode.class)
+                .build();
+        portLoadBalancerStore = storageService.<PortLoadBalancerId, PortLoadBalancer>consistentMapBuilder()
+                .withName("onos-portloadbalancer-store")
+                .withRelaxedReadConsistency()
+                .withSerializer(Serializer.using(serializer))
+                .build();
+        portLoadBalancerStore.addListener(portLoadBalancerStoreListener);
+        portLoadBalancerNextStore = storageService.<PortLoadBalancerId, Integer>consistentMapBuilder()
+                .withName("onos-portloadbalancer-next-store")
+                .withRelaxedReadConsistency()
+                .withSerializer(Serializer.using(serializer))
+                .build();
+        portLoadBalancerNextStore.addListener(portLoadBalancerNextStoreListener);
+        portLoadBalancerResStore = storageService.<PortLoadBalancerId, ApplicationId>consistentMapBuilder()
+                .withName("onos-portloadbalancer-res-store")
+                .withRelaxedReadConsistency()
+                .withSerializer(Serializer.using(serializer))
+                .build();
+        portLoadBalancerResStore.addListener(portLoadBalancerResStoreListener);
+
+        deviceService.addListener(deviceListener);
+
+        log.info("Started");
+    }
+
+    @Deactivate
+    public void deactivate() {
+        portLoadBalancerStore.removeListener(portLoadBalancerStoreListener);
+        portLoadBalancerNextStore.removeListener(portLoadBalancerNextStoreListener);
+
+        portLoadBalancerEventExecutor.shutdown();
+        portLoadBalancerProvExecutor.shutdown();
+        deviceEventExecutor.shutdown();
+
+        log.info("Stopped");
+    }
+
+    @Override
+    public void addListener(PortLoadBalancerListener listener) {
+        listeners.add(listener);
+    }
+
+    @Override
+    public void removeListener(PortLoadBalancerListener listener) {
+        listeners.remove(listener);
+    }
+
+    @Override
+    public PortLoadBalancer createOrUpdate(PortLoadBalancerId portLoadBalancerId, Set<PortNumber> ports,
+                                           PortLoadBalancerMode mode) {
+        log.debug("Putting {} -> {} {} into port load balancer store", portLoadBalancerId, mode, ports);
+        return Versioned.valueOrNull(portLoadBalancerStore.put(portLoadBalancerId,
+                new PortLoadBalancer(portLoadBalancerId, ports, mode)));
+    }
+
+    @Override
+    public PortLoadBalancer remove(PortLoadBalancerId portLoadBalancerId) {
+        ApplicationId reservation = Versioned.valueOrNull(portLoadBalancerResStore.get(portLoadBalancerId));
+        // Remove only if it is not used - otherwise it is necessary to release first
+        if (reservation == null) {
+            log.debug("Removing {} from port load balancer store", portLoadBalancerId);
+            return Versioned.valueOrNull(portLoadBalancerStore.remove(portLoadBalancerId));
+        }
+        log.warn("Removal {} from port load balancer store was not possible " +
+                          "due to a previous reservation", portLoadBalancerId);
+        return null;
+    }
+
+    @Override
+    public Map<PortLoadBalancerId, PortLoadBalancer> getPortLoadBalancers() {
+        return ImmutableMap.copyOf(portLoadBalancerStore.asJavaMap());
+    }
+
+    @Override
+    public PortLoadBalancer getPortLoadBalancer(PortLoadBalancerId portLoadBalancerId) {
+        return Versioned.valueOrNull(portLoadBalancerStore.get(portLoadBalancerId));
+    }
+
+    @Override
+    public Map<PortLoadBalancerId, Integer> getPortLoadBalancerNexts() {
+        return ImmutableMap.copyOf(portLoadBalancerNextStore.asJavaMap());
+    }
+
+    @Override
+    public int getPortLoadBalancerNext(PortLoadBalancerId portLoadBalancerId) {
+        return Versioned.valueOrNull(portLoadBalancerNextStore.get(portLoadBalancerId));
+    }
+
+    @Override
+    public boolean reserve(PortLoadBalancerId portLoadBalancerId, ApplicationId appId) {
+        // Check if the resource is available
+        ApplicationId reservation = Versioned.valueOrNull(portLoadBalancerResStore.get(portLoadBalancerId));
+        PortLoadBalancer portLoadBalancer = Versioned.valueOrNull(portLoadBalancerStore.get(portLoadBalancerId));
+        if (reservation == null && portLoadBalancer != null) {
+            log.debug("Reserving {} -> {} into port load balancer reservation store", portLoadBalancerId, appId);
+            return portLoadBalancerResStore.put(portLoadBalancerId, appId) == null;
+        } else if (reservation != null && reservation.equals(appId)) {
+            // App try to reserve the resource a second time
+            log.debug("Already reserved {} -> {} skip reservation", portLoadBalancerId, appId);
+            return true;
+        }
+        log.warn("Reservation failed {} -> {}", portLoadBalancerId, appId);
+        return false;
+    }
+
+    @Override
+    public boolean release(PortLoadBalancerId portLoadBalancerId, ApplicationId appId) {
+        // Check if the resource is reserved
+        ApplicationId reservation = Versioned.valueOrNull(portLoadBalancerResStore.get(portLoadBalancerId));
+        if (reservation != null && reservation.equals(appId)) {
+            log.debug("Removing {} -> {} from port load balancer reservation store", portLoadBalancerId, appId);
+            return portLoadBalancerResStore.remove(portLoadBalancerId) != null;
+        }
+        log.warn("Release failed {} -> {}", portLoadBalancerId, appId);
+        return false;
+    }
+
+    @Override
+    public ApplicationId getReservation(PortLoadBalancerId portLoadBalancerId) {
+        return Versioned.valueOrNull(portLoadBalancerResStore.get(portLoadBalancerId));
+    }
+
+    @Override
+    public Map<PortLoadBalancerId, ApplicationId> getReservations() {
+        return portLoadBalancerResStore.asJavaMap();
+    }
+
+    private class PortLoadBalancerStoreListener implements MapEventListener<PortLoadBalancerId, PortLoadBalancer> {
+        public void event(MapEvent<PortLoadBalancerId, PortLoadBalancer> event) {
+            switch (event.type()) {
+                case INSERT:
+                    log.debug("PortLoadBalancer {} insert new={}, old={}", event.key(), event.newValue(),
+                            event.oldValue());
+                    post(new PortLoadBalancerEvent(PortLoadBalancerEvent.Type.ADDED, event.newValue().value().data(),
+                            null));
+                    populatePortLoadBalancer(event.newValue().value());
+                    break;
+                case REMOVE:
+                    log.debug("PortLoadBalancer {} remove new={}, old={}", event.key(), event.newValue(),
+                            event.oldValue());
+                    post(new PortLoadBalancerEvent(PortLoadBalancerEvent.Type.REMOVED, null,
+                            event.oldValue().value().data()));
+                    revokePortLoadBalancer(event.oldValue().value());
+                    break;
+                case UPDATE:
+                    log.debug("PortLoadBalancer {} update new={}, old={}", event.key(), event.newValue(),
+                            event.oldValue());
+                    post(new PortLoadBalancerEvent(PortLoadBalancerEvent.Type.UPDATED, event.newValue().value().data(),
+                            event.oldValue().value().data()));
+                    updatePortLoadBalancer(event.newValue().value(), event.oldValue().value());
+                    break;
+                default:
+                    break;
+            }
+        }
+    }
+
+    private class PortLoadBalancerNextStoreListener implements MapEventListener<PortLoadBalancerId, Integer> {
+        public void event(MapEvent<PortLoadBalancerId, Integer> event) {
+            switch (event.type()) {
+                case INSERT:
+                    log.debug("PortLoadBalancer next {} insert new={}, old={}", event.key(), event.newValue(),
+                            event.oldValue());
+                    break;
+                case REMOVE:
+                    log.debug("PortLoadBalancer next {} remove new={}, old={}", event.key(), event.newValue(),
+                            event.oldValue());
+                    break;
+                case UPDATE:
+                    log.debug("PortLoadBalancer next {} update new={}, old={}", event.key(), event.newValue(),
+                            event.oldValue());
+                    break;
+                default:
+                    break;
+            }
+        }
+    }
+
+    private class PortLoadBalancerResStoreListener implements MapEventListener<PortLoadBalancerId, ApplicationId> {
+        public void event(MapEvent<PortLoadBalancerId, ApplicationId> event) {
+            switch (event.type()) {
+                case INSERT:
+                    log.debug("PortLoadBalancer reservation {} insert new={}, old={}", event.key(), event.newValue(),
+                              event.oldValue());
+                    break;
+                case REMOVE:
+                    log.debug("PortLoadBalancer reservation {} remove new={}, old={}", event.key(), event.newValue(),
+                              event.oldValue());
+                    break;
+                case UPDATE:
+                    log.debug("PortLoadBalancer reservation {} update new={}, old={}", event.key(), event.newValue(),
+                              event.oldValue());
+                    break;
+                default:
+                    break;
+            }
+        }
+    }
+
+    private class InternalDeviceListener implements DeviceListener {
+        // We want to manage only a subset of events and if we are the leader
+        @Override
+        public void event(DeviceEvent event) {
+            deviceEventExecutor.execute(() -> {
+                DeviceId deviceId = event.subject().id();
+                if (!isLocalLeader(deviceId)) {
+                    log.debug("Not the leader of {}. Skip event {}", deviceId, event);
+                    return;
+                }
+                // Populate or revoke according to the device availability
+                if (deviceService.isAvailable(deviceId)) {
+                    init(deviceId);
+                } else {
+                    cleanup(deviceId);
+                }
+            });
+        }
+        // Some events related to the devices are skipped
+        @Override
+        public boolean isRelevant(DeviceEvent event) {
+            return event.type() == DeviceEvent.Type.DEVICE_ADDED ||
+                    event.type() == DeviceEvent.Type.DEVICE_AVAILABILITY_CHANGED ||
+                    event.type() == DeviceEvent.Type.DEVICE_UPDATED;
+        }
+    }
+
+    private void post(PortLoadBalancerEvent portLoadBalancerEvent) {
+        portLoadBalancerEventExecutor.execute(() -> {
+            for (PortLoadBalancerListener l : listeners) {
+                if (l.isRelevant(portLoadBalancerEvent)) {
+                    l.event(portLoadBalancerEvent);
+                }
+            }
+        });
+    }
+
+    private void init(DeviceId deviceId) {
+        portLoadBalancerStore.entrySet().stream()
+                .filter(portLoadBalancerEntry -> portLoadBalancerEntry.getKey().deviceId().equals(deviceId))
+                .forEach(portLoadBalancerEntry -> populatePortLoadBalancer(portLoadBalancerEntry.getValue().value()));
+    }
+
+    private void cleanup(DeviceId deviceId) {
+        portLoadBalancerStore.entrySet().stream()
+                .filter(entry -> entry.getKey().deviceId().equals(deviceId))
+                .forEach(entry -> portLoadBalancerNextStore.remove(entry.getKey()));
+        log.debug("{} is removed from portLoadBalancerNextStore", deviceId);
+    }
+
+    private void populatePortLoadBalancer(PortLoadBalancer portLoadBalancer) {
+        DeviceId deviceId = portLoadBalancer.portLoadBalancerId().deviceId();
+        if (!isLocalLeader(deviceId)) {
+            log.debug("Not the leader of {}. Skip populatePortLoadBalancer {}", deviceId,
+                    portLoadBalancer.portLoadBalancerId());
+            return;
+        }
+
+        portLoadBalancerProvExecutor.execute(() -> {
+            Integer nextid = Versioned.valueOrNull(portLoadBalancerNextStore
+                    .get(portLoadBalancer.portLoadBalancerId()));
+            if (nextid == null) {
+                // Build a new context and new next objective
+                PortLoadBalancerObjectiveContext context =
+                        new PortLoadBalancerObjectiveContext(portLoadBalancer.portLoadBalancerId());
+                NextObjective nextObj = nextObjBuilder(portLoadBalancer.portLoadBalancerId(),
+                        portLoadBalancer.ports(), nextid).add(context);
+                // Finally submit, store, and register the resource
+                flowObjService.next(deviceId, nextObj);
+                portLoadBalancerNextStore.put(portLoadBalancer.portLoadBalancerId(), nextObj.id());
+            } else {
+                log.info("NextObj for {} already exists. Skip populatePortLoadBalancer",
+                        portLoadBalancer.portLoadBalancerId());
+            }
+        });
+    }
+
+    private void revokePortLoadBalancer(PortLoadBalancer portLoadBalancer) {
+        DeviceId deviceId = portLoadBalancer.portLoadBalancerId().deviceId();
+        if (!isLocalLeader(deviceId)) {
+            log.debug("Not the leader of {}. Skip revokePortLoadBalancer {}", deviceId,
+                    portLoadBalancer.portLoadBalancerId());
+            return;
+        }
+
+        portLoadBalancerProvExecutor.execute(() -> {
+            Integer nextid = Versioned.valueOrNull(portLoadBalancerNextStore.get(portLoadBalancer
+                    .portLoadBalancerId()));
+            if (nextid != null) {
+                // Build a new context and remove old next objective
+                PortLoadBalancerObjectiveContext context =
+                        new PortLoadBalancerObjectiveContext(portLoadBalancer.portLoadBalancerId());
+                NextObjective nextObj = nextObjBuilder(portLoadBalancer.portLoadBalancerId(), portLoadBalancer.ports(),
+                        nextid).remove(context);
+                // Finally submit and invalidate the store
+                flowObjService.next(deviceId, nextObj);
+                portLoadBalancerNextStore.remove(portLoadBalancer.portLoadBalancerId());
+            } else {
+                log.info("NextObj for {} does not exist. Skip revokePortLoadBalancer",
+                        portLoadBalancer.portLoadBalancerId());
+            }
+        });
+    }
+
+    private void updatePortLoadBalancer(PortLoadBalancer newPortLoadBalancer, PortLoadBalancer oldPortLoadBalancer) {
+        DeviceId deviceId = newPortLoadBalancer.portLoadBalancerId().deviceId();
+        if (!isLocalLeader(deviceId)) {
+            log.debug("Not the leader of {}. Skip updatePortLoadBalancer {}", deviceId,
+                    newPortLoadBalancer.portLoadBalancerId());
+            return;
+        }
+
+        portLoadBalancerProvExecutor.execute(() -> {
+            Integer nextid = Versioned.valueOrNull(portLoadBalancerNextStore
+                    .get(newPortLoadBalancer.portLoadBalancerId()));
+            if (nextid != null) {
+                // Compute modifications and context
+                PortLoadBalancerObjectiveContext context =
+                        new PortLoadBalancerObjectiveContext(newPortLoadBalancer.portLoadBalancerId());
+                Set<PortNumber> portsToBeAdded =
+                        Sets.difference(newPortLoadBalancer.ports(), oldPortLoadBalancer.ports());
+                Set<PortNumber> portsToBeRemoved =
+                        Sets.difference(oldPortLoadBalancer.ports(), newPortLoadBalancer.ports());
+                // and send them to the flowobj subsystem
+                if (!portsToBeAdded.isEmpty()) {
+                    flowObjService.next(deviceId, nextObjBuilder(newPortLoadBalancer.portLoadBalancerId(),
+                            portsToBeAdded, nextid)
+                            .addToExisting(context));
+                } else {
+                    log.debug("NextObj for {} nothing to add", newPortLoadBalancer.portLoadBalancerId());
+
+                }
+                if (!portsToBeRemoved.isEmpty()) {
+                    flowObjService.next(deviceId, nextObjBuilder(newPortLoadBalancer.portLoadBalancerId(),
+                            portsToBeRemoved, nextid)
+                            .removeFromExisting(context));
+                } else {
+                    log.debug("NextObj for {} nothing to remove", newPortLoadBalancer.portLoadBalancerId());
+                }
+            } else {
+                log.info("NextObj for {} does not exist. Skip updatePortLoadBalancer",
+                        newPortLoadBalancer.portLoadBalancerId());
+            }
+        });
+    }
+
+    private NextObjective.Builder nextObjBuilder(PortLoadBalancerId portLoadBalancerId, Set<PortNumber> ports,
+                                                 Integer nextId) {
+        if (nextId == null) {
+            nextId = flowObjService.allocateNextId();
+        }
+        // This metadata is used to pass the key to the driver.
+        // Some driver, e.g. OF-DPA, will use that information while creating load balancing group.
+        // TODO This is not an actual LAG port. In the future, we should extend metadata structure to carry
+        //      generic information. We should avoid using in_port in the metadata once generic metadata is available.
+        TrafficSelector meta = DefaultTrafficSelector.builder()
+                .matchInPort(PortNumber.portNumber(portLoadBalancerId.key())).build();
+        NextObjective.Builder nextObjBuilder = DefaultNextObjective.builder()
+                .withId(nextId)
+                .withMeta(meta)
+                .withType(NextObjective.Type.HASHED)
+                .fromApp(appId);
+        ports.forEach(port -> {
+            TrafficTreatment treatment = DefaultTrafficTreatment.builder().setOutput(port).build();
+            nextObjBuilder.addTreatment(DefaultNextTreatment.of(treatment));
+        });
+        return nextObjBuilder;
+    }
+
+    // Custom-built function, when the device is not available we need a fallback mechanism
+    private boolean isLocalLeader(DeviceId deviceId) {
+        if (!mastershipService.isLocalMaster(deviceId)) {
+            // When the device is available we just check the mastership
+            if (deviceService.isAvailable(deviceId)) {
+                return false;
+            }
+            // Fallback with Leadership service - device id is used as topic
+            NodeId leader = leadershipService.runForLeadership(
+                    deviceId.toString()).leaderNodeId();
+            // Verify if this node is the leader
+            return clusterService.getLocalNode().id().equals(leader);
+        }
+        return true;
+    }
+
+    private final class PortLoadBalancerObjectiveContext implements ObjectiveContext {
+        private final PortLoadBalancerId portLoadBalancerId;
+
+        private PortLoadBalancerObjectiveContext(PortLoadBalancerId portLoadBalancerId) {
+            this.portLoadBalancerId = portLoadBalancerId;
+        }
+
+        @Override
+        public void onSuccess(Objective objective) {
+            NextObjective nextObj = (NextObjective) objective;
+            log.debug("Successfully {} nextobj {} for port load balancer {}. NextObj={}",
+                    nextObj.op(), nextObj.id(), portLoadBalancerId, nextObj);
+            portLoadBalancerProvExecutor.execute(() -> onSuccessHandler(nextObj, portLoadBalancerId));
+        }
+
+        @Override
+        public void onError(Objective objective, ObjectiveError error) {
+            NextObjective nextObj = (NextObjective) objective;
+            log.warn("Failed to {} nextobj {} for port load balancer {} due to {}. NextObj={}",
+                    nextObj.op(), nextObj.id(), portLoadBalancerId, error, nextObj);
+            portLoadBalancerProvExecutor.execute(() -> onErrorHandler(nextObj, portLoadBalancerId));
+        }
+    }
+
+    private void onSuccessHandler(NextObjective nextObjective, PortLoadBalancerId portLoadBalancerId) {
+        // Operation done
+        PortLoadBalancerData oldPortLoadBalancerData = new PortLoadBalancerData(portLoadBalancerId);
+        PortLoadBalancerData newPortLoadBalancerData = new PortLoadBalancerData(portLoadBalancerId);
+        // Other operations will not lead to a generation of an event
+        switch (nextObjective.op()) {
+            case ADD:
+                newPortLoadBalancerData.setNextId(nextObjective.id());
+                post(new PortLoadBalancerEvent(PortLoadBalancerEvent.Type.INSTALLED, newPortLoadBalancerData,
+                        oldPortLoadBalancerData));
+                break;
+            case REMOVE:
+                oldPortLoadBalancerData.setNextId(nextObjective.id());
+                post(new PortLoadBalancerEvent(PortLoadBalancerEvent.Type.UNINSTALLED, newPortLoadBalancerData,
+                        oldPortLoadBalancerData));
+                break;
+            default:
+                break;
+        }
+    }
+
+    private void onErrorHandler(NextObjective nextObjective, PortLoadBalancerId portLoadBalancerId) {
+        // There was a failure
+        PortLoadBalancerData portLoadBalancerData = new PortLoadBalancerData(portLoadBalancerId);
+        // send FAILED event;
+        switch (nextObjective.op()) {
+            case ADD:
+                // If ADD is failing apps do not know the next id; let's update the store
+                portLoadBalancerNextStore.remove(portLoadBalancerId);
+                portLoadBalancerResStore.remove(portLoadBalancerId);
+                portLoadBalancerStore.remove(portLoadBalancerId);
+                post(new PortLoadBalancerEvent(PortLoadBalancerEvent.Type.FAILED, portLoadBalancerData,
+                        portLoadBalancerData));
+                break;
+            case ADD_TO_EXISTING:
+                // If ADD_TO_EXISTING is failing let's remove the failed ports
+                Collection<PortNumber> addedPorts = nextObjective.next().stream()
+                        .flatMap(t -> t.allInstructions().stream())
+                        .filter(i -> i.type() == Instruction.Type.OUTPUT)
+                        .map(i -> ((Instructions.OutputInstruction) i).port())
+                        .collect(Collectors.toList());
+                portLoadBalancerStore.compute(portLoadBalancerId, (key, value) -> {
+                    if (value != null && value.ports() != null && !value.ports().isEmpty()) {
+                        value.ports().removeAll(addedPorts);
+                    }
+                    return value;
+                });
+                portLoadBalancerData.setNextId(nextObjective.id());
+                post(new PortLoadBalancerEvent(PortLoadBalancerEvent.Type.FAILED, portLoadBalancerData,
+                        portLoadBalancerData));
+                break;
+            case REMOVE_FROM_EXISTING:
+                // If REMOVE_TO_EXISTING is failing let's re-add the failed ports
+                Collection<PortNumber> removedPorts = nextObjective.next().stream()
+                        .flatMap(t -> t.allInstructions().stream())
+                        .filter(i -> i.type() == Instruction.Type.OUTPUT)
+                        .map(i -> ((Instructions.OutputInstruction) i).port())
+                        .collect(Collectors.toList());
+                portLoadBalancerStore.compute(portLoadBalancerId, (key, value) -> {
+                    if (value != null && value.ports() != null) {
+                        value.ports().addAll(removedPorts);
+                    }
+                    return value;
+                });
+                portLoadBalancerData.setNextId(nextObjective.id());
+                post(new PortLoadBalancerEvent(PortLoadBalancerEvent.Type.FAILED, portLoadBalancerData,
+                        portLoadBalancerData));
+                break;
+            case VERIFY:
+            case REMOVE:
+                // If ADD/REMOVE_TO_EXISTING, REMOVE and VERIFY are failing let's send
+                // also the info about the next id
+                portLoadBalancerData.setNextId(nextObjective.id());
+                post(new PortLoadBalancerEvent(PortLoadBalancerEvent.Type.FAILED, portLoadBalancerData,
+                        portLoadBalancerData));
+                break;
+            default:
+                break;
+        }
+
+    }
+}
\ No newline at end of file
diff --git a/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/app/package-info.java b/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/app/package-info.java
new file mode 100644
index 0000000..a92eee5
--- /dev/null
+++ b/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/app/package-info.java
@@ -0,0 +1,20 @@
+/*
+ * Copyright 2018-present Open Networking 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.
+ */
+
+/**
+ * Port load balancer app.
+ */
+package org.onosproject.portloadbalancer.app;
\ No newline at end of file
diff --git a/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/cli/PortLoadBalancerAddCommand.java b/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/cli/PortLoadBalancerAddCommand.java
new file mode 100644
index 0000000..7f0c124
--- /dev/null
+++ b/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/cli/PortLoadBalancerAddCommand.java
@@ -0,0 +1,79 @@
+/*
+ * Copyright 2018-present Open Networking 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.
+ */
+package org.onosproject.portloadbalancer.cli;
+
+import com.google.common.collect.Sets;
+import org.apache.karaf.shell.api.action.Argument;
+import org.apache.karaf.shell.api.action.Command;
+import org.apache.karaf.shell.api.action.lifecycle.Service;
+import org.onosproject.cli.AbstractShellCommand;
+import org.onosproject.portloadbalancer.api.PortLoadBalancer;
+import org.onosproject.portloadbalancer.api.PortLoadBalancerAdminService;
+import org.onosproject.portloadbalancer.api.PortLoadBalancerId;
+import org.onosproject.portloadbalancer.api.PortLoadBalancerMode;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.PortNumber;
+
+import java.util.Set;
+import java.util.stream.Collectors;
+
+/**
+ * Command to add a port load balancer.
+ */
+@Service
+@Command(scope = "onos", name = "plb-add", description = "Create or update port load balancer ")
+public class PortLoadBalancerAddCommand extends AbstractShellCommand {
+    @Argument(index = 0, name = "deviceId",
+            description = "Device ID",
+            required = true, multiValued = false)
+    private String deviceIdStr;
+
+    @Argument(index = 1, name = "key",
+            description = "port load balancer key",
+            required = true, multiValued = false)
+    private String keyStr;
+
+    @Argument(index = 2, name = "mode",
+            description = "port load balancer mode. STATIC or LACP",
+            required = true, multiValued = false)
+    private String modeStr;
+
+    @Argument(index = 3, name = "ports",
+            description = "port load balancer physical ports",
+            required = true, multiValued = true)
+    private String[] portsStr;
+
+    // Operation constants
+    private static final String CREATE = "Create";
+    private static final String UPDATE = "Update";
+
+    @Override
+    protected void doExecute() {
+        DeviceId deviceId = DeviceId.deviceId(deviceIdStr);
+        int portLoadBalancerKey = Integer.parseInt(keyStr);
+
+        PortLoadBalancerMode mode = PortLoadBalancerMode.valueOf(modeStr.toUpperCase());
+        Set<PortNumber> ports = Sets.newHashSet(portsStr).stream()
+                .map(PortNumber::fromString).collect(Collectors.toSet());
+
+        PortLoadBalancerAdminService portLoadBalancerAdminService = get(PortLoadBalancerAdminService.class);
+        PortLoadBalancerId portLoadBalancerId = new PortLoadBalancerId(deviceId, portLoadBalancerKey);
+        PortLoadBalancer portLoadBalancer = portLoadBalancerAdminService
+                .createOrUpdate(portLoadBalancerId, ports, mode);
+        print("%s of %s executed", portLoadBalancer == null ? CREATE : UPDATE, portLoadBalancerId);
+
+    }
+}
diff --git a/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/cli/PortLoadBalancerListCommand.java b/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/cli/PortLoadBalancerListCommand.java
new file mode 100644
index 0000000..6850b0f
--- /dev/null
+++ b/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/cli/PortLoadBalancerListCommand.java
@@ -0,0 +1,50 @@
+/*
+ * Copyright 2018-present Open Networking 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.
+ */
+package org.onosproject.portloadbalancer.cli;
+
+import org.apache.karaf.shell.api.action.Command;
+import org.apache.karaf.shell.api.action.lifecycle.Service;
+import org.onosproject.cli.AbstractShellCommand;
+import org.onosproject.core.ApplicationId;
+import org.onosproject.portloadbalancer.api.PortLoadBalancer;
+import org.onosproject.portloadbalancer.api.PortLoadBalancerId;
+import org.onosproject.portloadbalancer.api.PortLoadBalancerService;
+
+import java.util.Map;
+
+/**
+ * Command to show all port load balancers.
+ */
+@Service
+@Command(scope = "onos", name = "plbs", description = "Lists port load balancers")
+public class PortLoadBalancerListCommand extends AbstractShellCommand {
+
+    // Operation constant
+    private static final String AVAILABLE = "Available";
+
+    @Override
+    public void doExecute() {
+        PortLoadBalancerService service = get(PortLoadBalancerService.class);
+        // Get port load balancers and reservations
+        Map<PortLoadBalancerId, PortLoadBalancer> portLoadBalancerStore = service.getPortLoadBalancers();
+        Map<PortLoadBalancerId, ApplicationId> portLoadBalancerResStore = service.getReservations();
+        // Print id -> ports, mode, reservation
+        portLoadBalancerStore.forEach((portLoadBalancerId, portLoadBalancer) ->
+                print("%s -> %s, %s, %s", portLoadBalancerId, portLoadBalancer.ports(), portLoadBalancer.mode(),
+                        portLoadBalancerResStore.get(portLoadBalancerId) == null ? AVAILABLE :
+                                portLoadBalancerResStore.get(portLoadBalancerId).name()));
+    }
+}
\ No newline at end of file
diff --git a/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/cli/PortLoadBalancerRemoveCommand.java b/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/cli/PortLoadBalancerRemoveCommand.java
new file mode 100644
index 0000000..8d19a27
--- /dev/null
+++ b/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/cli/PortLoadBalancerRemoveCommand.java
@@ -0,0 +1,57 @@
+/*
+ * Copyright 2018-present Open Networking 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.
+ */
+package org.onosproject.portloadbalancer.cli;
+
+import org.apache.karaf.shell.api.action.Argument;
+import org.apache.karaf.shell.api.action.Command;
+import org.apache.karaf.shell.api.action.lifecycle.Service;
+import org.onosproject.cli.AbstractShellCommand;
+import org.onosproject.portloadbalancer.api.PortLoadBalancer;
+import org.onosproject.portloadbalancer.api.PortLoadBalancerAdminService;
+import org.onosproject.portloadbalancer.api.PortLoadBalancerId;
+import org.onosproject.net.DeviceId;
+
+/**
+ * Command to remove a port load balancer.
+ */
+@Service
+@Command(scope = "onos", name = "plb-remove", description = "Remove port load balancers ")
+public class PortLoadBalancerRemoveCommand extends AbstractShellCommand {
+    @Argument(index = 0, name = "deviceId",
+            description = "Device ID",
+            required = true, multiValued = false)
+    private String deviceIdStr;
+
+    @Argument(index = 1, name = "key",
+            description = "port load balancer key",
+            required = true, multiValued = false)
+    private String keyStr;
+
+    // Operation constants
+    private static final String EXECUTED = "Executed";
+    private static final String FAILED = "Failed";
+
+    @Override
+    protected void doExecute() {
+        DeviceId deviceId = DeviceId.deviceId(deviceIdStr);
+        int portLoadBalancerKey = Integer.parseInt(keyStr);
+
+        PortLoadBalancerAdminService portLoadBalancerAdminService = get(PortLoadBalancerAdminService.class);
+        PortLoadBalancerId portLoadBalancerId = new PortLoadBalancerId(deviceId, portLoadBalancerKey);
+        PortLoadBalancer portLoadBalancer = portLoadBalancerAdminService.remove(portLoadBalancerId);
+        print("Removal of %s %s", portLoadBalancerId, portLoadBalancer != null ? EXECUTED : FAILED);
+    }
+}
diff --git a/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/cli/package-info.java b/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/cli/package-info.java
new file mode 100644
index 0000000..7e448ce
--- /dev/null
+++ b/apps/portloadbalancer/src/main/java/org/onosproject/portloadbalancer/cli/package-info.java
@@ -0,0 +1,20 @@
+/*
+ * Copyright 2018-present Open Networking 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.
+ */
+
+/**
+ * Port load balancer CLI.
+ */
+package org.onosproject.portloadbalancer.cli;
\ No newline at end of file