[ONOS-4176] Implement influxdb retriever for querying metrics

Change-Id: Ia1f3fc4fb3c76fafd003320940b8fe16b039ddae

@@ -21,5 +21,10 @@
         <bundle>mvn:${project.groupId}/onos-app-influxdb/${project.version}</bundle>
         <bundle>mvn:${project.groupId}/onos-app-influxdb/${project.version}</bundle>
         <bundle>wrap:mvn:com.izettle/metrics-influxdb/1.1.1$Bundle-SymbolicName=metrics-influxdb&amp;Bundle-Version=1.1.1</bundle>
         <bundle>wrap:mvn:com.izettle/metrics-influxdb/1.1.1$Bundle-SymbolicName=metrics-influxdb&amp;Bundle-Version=1.1.1</bundle>
         <bundle>mvn:commons-codec/commons-codec/1.10</bundle>
         <bundle>mvn:commons-codec/commons-codec/1.10</bundle>
+        <bundle>wrap:mvn:org.influxdb/influxdb-java/2.1$Bundle-SymbolicName=influxdb-java&amp;Bundle-Version=2.1</bundle>
+        <bundle>wrap:mvn:com.squareup.retrofit/retrofit/1.9.0$Bundle-SymbolicName=retrofit&amp;Bundle-Version=1.9.0</bundle>
+        <bundle>wrap:mvn:com.squareup.okhttp/okhttp/2.4.0$Bundle-SymbolicName=okhttp&amp;Bundle-Version=2.4.0</bundle>
+        <bundle>wrap:mvn:com.squareup.okio/okio/1.4.0$Bundle-SymbolicName=okio&amp;Bundle-Version=1.4.0</bundle>
+        <bundle>mvn:com.google.code.gson/gson/2.3.1</bundle>
     </feature>
     </feature>
 </features>
 </features>

@@ -71,6 +71,11 @@
             <version>1.1.1</version>
             <version>1.1.1</version>
         </dependency>
         </dependency>
         <dependency>
         <dependency>
+            <groupId>org.influxdb</groupId>
+            <artifactId>influxdb-java</artifactId>
+            <version>2.1</version>
+        </dependency>
+        <dependency>
             <groupId>org.onosproject</groupId>
             <groupId>org.onosproject</groupId>
             <artifactId>onos-api</artifactId>
             <artifactId>onos-api</artifactId>
             <version>${project.version}</version>
             <version>${project.version}</version>

+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * 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.influxdbmetrics;
+
+import com.google.common.collect.BiMap;
+import com.google.common.collect.EnumHashBiMap;
+import com.google.common.collect.Lists;
+import com.google.common.collect.Maps;
+import com.google.common.collect.Sets;
+import org.apache.commons.lang.StringUtils;
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Modified;
+import org.apache.felix.scr.annotations.Property;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.ReferenceCardinality;
+import org.apache.felix.scr.annotations.Service;
+import org.influxdb.InfluxDB;
+import org.influxdb.InfluxDBFactory;
+import org.influxdb.dto.Query;
+import org.influxdb.dto.QueryResult;
+import org.onlab.util.Tools;
+import org.onosproject.cfg.ComponentConfigService;
+import org.onosproject.cluster.NodeId;
+import org.onosproject.core.CoreService;
+import org.osgi.service.component.ComponentContext;
+import org.slf4j.Logger;
+
+import java.util.Dictionary;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.TimeUnit;
+
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * A Metric retriever implementation for querying metrics from influxDB server.
+ */
+@Component(immediate = true)
+@Service
+public class DefaultInfluxDbMetricsRetriever implements InfluxDbMetricsRetriever {
+
+    private final Logger log = getLogger(getClass());
+
+    private static final String DEFAULT_PROTOCOL = "http";
+    private static final String DEFAULT_ADDRESS = "localhost";
+    private static final int DEFAULT_PORT = 8086;
+    private static final String DEFAULT_DATABASE = "onos";
+    private static final String DEFAULT_USERNAME = "onos";
+    private static final String DEFAULT_PASSWORD = "onos.password";
+    private static final String DEFAULT_POLICY = "default";
+    private static final String COLON_SEPARATOR = ":";
+    private static final String SLASH_SEPARATOR = "//";
+    private static final String BRACKET_START = "[";
+    private static final String BRACKET_END = "]";
+    private static final String METRIC_DELIMITER = ".";
+    private static final int NUB_OF_DELIMITER = 3;
+
+    private static final BiMap<TimeUnit, String> TIME_UNIT_MAP =
+            EnumHashBiMap.create(TimeUnit.class);
+
+    static {
+        // key is TimeUnit enumeration type
+        // value is influx database time unit keyword
+        TIME_UNIT_MAP.put(TimeUnit.DAYS, "d");
+        TIME_UNIT_MAP.put(TimeUnit.HOURS, "h");
+        TIME_UNIT_MAP.put(TimeUnit.MINUTES, "m");
+        TIME_UNIT_MAP.put(TimeUnit.SECONDS, "s");
+    }
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected CoreService coreService;
+
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected ComponentConfigService cfgService;
+
+    @Property(name = "address", value = DEFAULT_ADDRESS,
+            label = "IP address of influxDB server; " +
+                    "default is localhost")
+    protected String address = DEFAULT_ADDRESS;
+
+    @Property(name = "port", intValue = DEFAULT_PORT,
+            label = "Port number of influxDB server; " +
+                    "default is 8086")
+    protected int port = DEFAULT_PORT;
+
+    @Property(name = "database", value = DEFAULT_DATABASE,
+            label = "Database name of influxDB server; " +
+                    "default is onos")
+    protected String database = DEFAULT_DATABASE;
+
+    @Property(name = "username", value = DEFAULT_USERNAME,
+            label = "Username of influxDB server; default is onos")
+    protected String username = DEFAULT_USERNAME;
+
+    @Property(name = "password", value = DEFAULT_PASSWORD,
+            label = "Password of influxDB server; default is onos.password")
+    protected String password = DEFAULT_PASSWORD;
+
+    InfluxDB influxDB;
+
+    @Activate
+    public void activate() {
+        cfgService.registerProperties(getClass());
+        coreService.registerApplication("org.onosproject.influxdbmetrics");
+
+        config();
+
+        log.info("Started");
+    }
+
+    @Deactivate
+    public void deactivate() {
+        cfgService.unregisterProperties(getClass(), false);
+
+        log.info("Stopped");
+    }
+
+    @Modified
+    public void modified(ComponentContext context) {
+        readComponentConfiguration(context);
+        config();
+    }
+
+    private void config() {
+        StringBuilder url = new StringBuilder();
+        url.append(DEFAULT_PROTOCOL);
+        url.append(COLON_SEPARATOR + SLASH_SEPARATOR);
+        url.append(address);
+        url.append(COLON_SEPARATOR);
+        url.append(port);
+
+        influxDB = InfluxDBFactory.connect(url.toString(), username, password);
+    }
+
+    @Override
+    public Map<NodeId, Map<String, List<InfluxMetric>>> allMetrics(int period,
+                                                             TimeUnit unit) {
+        Map<NodeId, Set<String>> nameMap = allMetricNames();
+        Map<NodeId, Map<String, List<InfluxMetric>>> metricsMap = Maps.newHashMap();
+
+        nameMap.forEach((nodeId, metricNames) ->
+                metricsMap.putIfAbsent(nodeId, metricsByNodeId(nodeId, period, unit))
+        );
+
+        return metricsMap;
+    }
+
+    @Override
+    public Map<String, List<InfluxMetric>> metricsByNodeId(NodeId nodeId, int period,
+                                                     TimeUnit unit) {
+        Map<NodeId, Set<String>> nameMap = allMetricNames();
+        Map<String, List<InfluxMetric>> map = Maps.newHashMap();
+
+        nameMap.get(nodeId).forEach(metricName -> {
+            List<InfluxMetric> value = metric(nodeId, metricName, period, unit);
+            if (value != null) {
+                map.putIfAbsent(metricName, value);
+            }
+        });
+
+        return map;
+    }
+
+    @Override
+    public Map<NodeId, List<InfluxMetric>> metricsByName(String metricName, int period,
+                                                   TimeUnit unit) {
+        Map<NodeId, List<InfluxMetric>> map = Maps.newHashMap();
+        List<InfluxMetric> metrics = Lists.newArrayList();
+        String queryPrefix = new StringBuilder()
+                .append("SELECT m1_rate FROM")
+                .append(database)
+                .append(METRIC_DELIMITER)
+                .append(quote(DEFAULT_POLICY))
+                .append(METRIC_DELIMITER)
+                .toString();
+        String querySuffix = new StringBuilder()
+                .append(" WHERE time > now() - ")
+                .append(period)
+                .append(unitString(unit))
+                .toString();
+
+        allMetricNames().keySet().forEach(nodeId -> {
+            String queryString = new StringBuilder()
+                    .append(queryPrefix)
+                    .append(quote(nodeId + METRIC_DELIMITER + metricName))
+                    .append(querySuffix)
+                    .toString();
+            Query query = new Query(queryString, database);
+            List<QueryResult.Result> results = influxDB.query(query).getResults();
+
+            if (results != null && results.get(0) != null
+                    && results.get(0).getSeries() != null) {
+
+                results.get(0).getSeries().get(0).getValues().forEach(value ->
+                    metrics.add(new DefaultInfluxMetric.Builder()
+                            .time((String) value.get(0))
+                            .oneMinRate((Double) value.get(1))
+                            .build()));
+                map.putIfAbsent(nodeId, metrics);
+            }
+        });
+
+        return map;
+    }
+
+    @Override
+    public List<InfluxMetric> metric(NodeId nodeId, String metricName,
+                               int period, TimeUnit unit) {
+        List<InfluxMetric> metrics = Lists.newArrayList();
+        String queryString = new StringBuilder()
+                .append("SELECT m1_rate FROM ")
+                .append(database)
+                .append(METRIC_DELIMITER)
+                .append(quote(DEFAULT_POLICY))
+                .append(METRIC_DELIMITER)
+                .append(quote(nodeId + METRIC_DELIMITER + metricName))
+                .append(" WHERE time > now() - ")
+                .append(period)
+                .append(unitString(unit))
+                .toString();
+
+        Query query = new Query(queryString, database);
+        List<QueryResult.Result> results = influxDB.query(query).getResults();
+
+        if (results != null && results.get(0) != null
+                && results.get(0).getSeries() != null) {
+
+            results.get(0).getSeries().get(0).getValues().forEach(value ->
+                    metrics.add(new DefaultInfluxMetric.Builder()
+                            .time((String) value.get(0))
+                            .oneMinRate((Double) value.get(1))
+                            .build()));
+            return metrics;
+        }
+
+        return null;
+    }
+
+    @Override
+    public Map<NodeId, Map<String, InfluxMetric>> allMetrics() {
+        Map<NodeId, Set<String>> nameMap = allMetricNames();
+        Map<NodeId, Map<String, InfluxMetric>> metricsMap = Maps.newHashMap();
+
+        nameMap.forEach((nodeId, metricNames) ->
+            metricsMap.putIfAbsent(nodeId, metricsByNodeId(nodeId))
+        );
+
+        return metricsMap;
+    }
+
+    @Override
+    public Map<String, InfluxMetric> metricsByNodeId(NodeId nodeId) {
+        Map<NodeId, Set<String>> nameMap = allMetricNames();
+        Map<String, InfluxMetric> map = Maps.newHashMap();
+
+        nameMap.get(nodeId).forEach(metricName -> {
+            InfluxMetric value = metric(nodeId, metricName);
+            if (value != null) {
+                map.putIfAbsent(metricName, value);
+            }
+        });
+
+        return map;
+    }
+
+    @Override
+    public Map<NodeId, InfluxMetric> metricsByName(String metricName) {
+        Map<NodeId, InfluxMetric> map = Maps.newHashMap();
+        String queryPrefix = new StringBuilder()
+                .append("SELECT m1_rate FROM")
+                .append(database)
+                .append(METRIC_DELIMITER)
+                .append(quote(DEFAULT_POLICY))
+                .append(METRIC_DELIMITER)
+                .toString();
+        String querySuffix = new StringBuilder()
+                .append(" LIMIT 1")
+                .toString();
+
+        allMetricNames().keySet().forEach(nodeId -> {
+            String queryString = new StringBuilder()
+                    .append(queryPrefix)
+                    .append(quote(nodeId + METRIC_DELIMITER + metricName))
+                    .append(querySuffix)
+                    .toString();
+            Query query = new Query(queryString, database);
+            List<QueryResult.Result> results = influxDB.query(query).getResults();
+
+            if (results != null && results.get(0) != null
+                    && results.get(0).getSeries() != null) {
+                InfluxMetric metric = new DefaultInfluxMetric.Builder()
+                        .time((String) results.get(0).getSeries().get(0).getValues().get(0).get(0))
+                        .oneMinRate((Double) results.get(0).getSeries().get(0)
+                                .getValues().get(0).get(1)).build();
+                map.putIfAbsent(nodeId, metric);
+            }
+        });
+
+        return map;
+    }
+
+    @Override
+    public InfluxMetric metric(NodeId nodeId, String metricName) {
+        String queryString = new StringBuilder()
+                .append("SELECT m1_rate FROM ")
+                .append(database)
+                .append(METRIC_DELIMITER)
+                .append(quote(DEFAULT_POLICY))
+                .append(METRIC_DELIMITER)
+                .append(quote(nodeId + METRIC_DELIMITER + metricName))
+                .append(" LIMIT 1")
+                .toString();
+
+        Query query = new Query(queryString, database);
+        List<QueryResult.Result> results = influxDB.query(query).getResults();
+
+        if (results != null && results.get(0) != null
+                && results.get(0).getSeries() != null) {
+            return new DefaultInfluxMetric.Builder()
+                    .time((String) results.get(0).getSeries().get(0).getValues().get(0).get(0))
+                    .oneMinRate((Double) results.get(0).getSeries().get(0)
+                            .getValues().get(0).get(1)).build();
+        }
+
+        return null;
+    }
+
+    private String unitString(TimeUnit unit) {
+        return TIME_UNIT_MAP.get(unit) == null ? "h" : TIME_UNIT_MAP.get(unit);
+    }
+
+    private String quote(String str) {
+        return "\"" + str + "\"";
+    }
+
+    /**
+     * Returns all metric names that bound with node identification.
+     *
+     * @return all metric names
+     */
+    protected Map<NodeId, Set<String>> allMetricNames() {
+        Map<NodeId, Set<String>> metricNameMap = Maps.newHashMap();
+        Query query = new Query("SHOW MEASUREMENTS", database);
+        List<QueryResult.Result> results = influxDB.query(query).getResults();
+        List<List<Object>> rawMetricNames = results.get(0).getSeries().get(0).getValues();
+
+        rawMetricNames.forEach(rawMetricName -> {
+            String nodeIdStr = getNodeId(strip(rawMetricName.toString()));
+
+            if (nodeIdStr != null) {
+                NodeId nodeId = NodeId.nodeId(nodeIdStr);
+                String metricName = getMetricName(strip(rawMetricName.toString()));
+
+                if (!metricNameMap.containsKey(nodeId)) {
+                    metricNameMap.putIfAbsent(nodeId, Sets.newHashSet());
+                }
+
+                if (metricName != null) {
+                    metricNameMap.get(nodeId).add(metricName);
+                }
+            }
+        });
+
+        return metricNameMap;
+    }
+
+    /**
+     * Strips special bracket from the full name.
+     *
+     * @param fullName full name
+     * @return bracket stripped string
+     */
+    private String strip(String fullName) {
+        return StringUtils.strip(StringUtils.strip(fullName, BRACKET_START), BRACKET_END);
+    }
+
+    /**
+     * Returns metric name from full name.
+     * The elements in full name is split by using '.';
+     * We assume that the metric name always comes after the last three '.'
+     *
+     * @param fullName full name
+     * @return metric name
+     */
+    private String getMetricName(String fullName) {
+        int index = StringUtils.lastOrdinalIndexOf(fullName,
+                METRIC_DELIMITER, NUB_OF_DELIMITER);
+        if (index != -1) {
+            return StringUtils.substring(fullName, index + 1);
+        } else {
+            log.warn("Database {} contains malformed metric name.", database);
+            return null;
+        }
+    }
+
+    /**
+     * Returns node id from full name.
+     * The elements in full name is split by using '.';
+     * We assume that the node id always comes before the last three '.'
+     *
+     * @param fullName full name
+     * @return node id
+     */
+    private String getNodeId(String fullName) {
+        int index = StringUtils.lastOrdinalIndexOf(fullName,
+                METRIC_DELIMITER, NUB_OF_DELIMITER);
+        if (index != -1) {
+            return StringUtils.substring(fullName, 0, index);
+        } else {
+            log.warn("Database {} contains malformed node id.", database);
+            return null;
+        }
+    }
+
+    /**
+     * Extracts properties from the component configuration context.
+     *
+     * @param context the component context
+     */
+    private void readComponentConfiguration(ComponentContext context) {
+        Dictionary<?, ?> properties = context.getProperties();
+
+        String addressStr = Tools.get(properties, "address");
+        address = addressStr != null ? addressStr : DEFAULT_ADDRESS;
+        log.info("Configured. InfluxDB server address is {}", address);
+
+        String databaseStr = Tools.get(properties, "database");
+        database = databaseStr != null ? databaseStr : DEFAULT_DATABASE;
+        log.info("Configured. InfluxDB server database is {}", database);
+
+        String usernameStr = Tools.get(properties, "username");
+        username = usernameStr != null ? usernameStr : DEFAULT_USERNAME;
+        log.info("Configured. InfluxDB server username is {}", username);
+
+        String passwordStr = Tools.get(properties, "password");
+        password = passwordStr != null ? passwordStr : DEFAULT_PASSWORD;
+        log.info("Configured. InfluxDB server password is {}", password);
+
+        Integer portConfigured = Tools.getIntegerProperty(properties, "port");
+        if (portConfigured == null) {
+            port = DEFAULT_PORT;
+            log.info("InfluxDB port is not configured, default value is {}", port);
+        } else {
+            port = portConfigured;
+            log.info("Configured. InfluxDB port is configured to {}", port);
+        }
+    }
+}

+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * 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.influxdbmetrics;
+
+import org.apache.commons.lang.StringUtils;
+import org.joda.time.DateTime;
+import org.joda.time.format.DateTimeFormat;
+import org.joda.time.format.DateTimeFormatter;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Default implementation of influx metric.
+ */
+public final class DefaultInfluxMetric implements InfluxMetric {
+
+    private double oneMinRate;
+    private DateTime time;
+
+    private DefaultInfluxMetric(double oneMinRate, DateTime time) {
+        this.oneMinRate = oneMinRate;
+        this.time = time;
+    }
+
+    @Override
+    public double oneMinRate() {
+        return oneMinRate;
+    }
+
+    @Override
+    public DateTime time() {
+        return time;
+    }
+
+    public static final class Builder implements InfluxMetric.Builder {
+
+        private double oneMinRate;
+        private String timestamp;
+        private static final String TIMESTAMP_MSG = "Must specify a timestamp.";
+        private static final String ONE_MIN_RATE_MSG = "Must specify one minute rate.";
+
+        public Builder() {
+        }
+
+        @Override
+        public InfluxMetric.Builder oneMinRate(double rate) {
+            this.oneMinRate = rate;
+            return this;
+        }
+
+        @Override
+        public InfluxMetric.Builder time(String time) {
+            this.timestamp = time;
+            return this;
+        }
+
+        @Override
+        public InfluxMetric build() {
+            checkNotNull(oneMinRate, ONE_MIN_RATE_MSG);
+            checkNotNull(timestamp, TIMESTAMP_MSG);
+
+            return new DefaultInfluxMetric(oneMinRate, parseTime(timestamp));
+        }
+
+        private DateTime parseTime(String time) {
+            String reformatTime = StringUtils.replace(StringUtils.replace(time, "T", " "), "Z", "");
+            DateTimeFormatter formatter = DateTimeFormat.forPattern("yyyy-MM-dd HH:mm:ss");
+            return formatter.parseDateTime(reformatTime);
+        }
+    }
+}

+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * 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.influxdbmetrics;
+
+import org.onosproject.cluster.NodeId;
+
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * A Metric retriever interface for querying metrics value from influxDB server.
+ */
+public interface InfluxDbMetricsRetriever {
+
+    /**
+     * Returns last metric values from all nodes.
+     *
+     * @return all metrics from all nodes
+     */
+    Map<NodeId, Map<String, InfluxMetric>> allMetrics();
+
+    /**
+     * Returns last metric values from a node.
+     *
+     * @param nodeId node identification
+     * @return all metrics from a given node
+     */
+    Map<String, InfluxMetric> metricsByNodeId(NodeId nodeId);
+
+    /**
+     * Returns a collection of last metric values from all nodes.
+     *
+     * @param metricName metric name
+     * @return a collection of metrics from all nodes
+     */
+    Map<NodeId, InfluxMetric> metricsByName(String metricName);
+
+    /**
+     * Returns a last metric value from a given node.
+     *
+     * @param nodeId node identification
+     * @param metricName metric name
+     * @return a metric value from a given node
+     */
+    InfluxMetric metric(NodeId nodeId, String metricName);
+
+    /**
+     * Returns metric values of all nodes within a given period of time.
+     *
+     * @param period projected period
+     * @param unit time unit
+     * @return all metric values of all nodes
+     */
+    Map<NodeId, Map<String, List<InfluxMetric>>> allMetrics(int period, TimeUnit unit);
+
+    /**
+     * Returns metric values of a node within a given period of time.
+     *
+     * @param nodeId node identification
+     * @param period projected period
+     * @param unit time unit
+     * @return metric value of a node
+     */
+    Map<String, List<InfluxMetric>> metricsByNodeId(NodeId nodeId, int period, TimeUnit unit);
+
+    /**
+     * Returns a collection of last metric values of all nodes within a given period of time.
+     *
+     * @param metricName metric name
+     * @param period projected period
+     * @param unit time unit
+     * @return metric value of all nodes
+     */
+    Map<NodeId, List<InfluxMetric>> metricsByName(String metricName, int period, TimeUnit unit);
+
+    /**
+     * Returns metric value of a given node within a given period of time.
+     *
+     * @param nodeId node identification
+     * @param metricName metric name
+     * @param period projected period
+     * @param unit time unit
+     * @return metric value of a node
+     */
+    List<InfluxMetric> metric(NodeId nodeId, String metricName, int period, TimeUnit unit);
+}

+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * 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.influxdbmetrics;
+
+import org.joda.time.DateTime;
+
+/**
+ * Metric that represents all values queried from influx database.
+ */
+public interface InfluxMetric {
+
+    /**
+     * Returns one minute rate of the given metric.
+     *
+     * @return one minute rate of the given metric
+     */
+    double oneMinRate();
+
+
+    /**
+     * Returns collected timestamp of the given metric.
+     *
+     * @return collected timestamp of the given metric
+     */
+    DateTime time();
+
+    /**
+     * A builder of InfluxMetric.
+     */
+    interface Builder {
+
+        /**
+         * Sets one minute rate.
+         *
+         * @param rate one minute rate
+         * @return builder object
+         */
+        Builder oneMinRate(double rate);
+
+        /**
+         * Sets collected timestamp.
+         *
+         * @param time timestamp
+         * @return builder object
+         */
+        Builder time(String time);
+
+        /**
+         * Builds a influx metric instance.
+         *
+         * @return influx metric instance
+         */
+        InfluxMetric build();
+    }
+}