Add CPU usage and system load to metric (#749)

Signed-off-by: Carpenter Lee <hooleeucas@163.com>

sentinel-core/src/main/java/com/alibaba/csp/sentinel/Constants.java

@@ -43,6 +43,16 @@ public final class Constants {
      */
     public final static String TOTAL_IN_RESOURCE_NAME = "__total_inbound_traffic__";
 
+    /**
+     * A virtual resource identifier for cpu usage statistics (since 1.6.1).
+     */
+    public final static String CPU_USAGE_RESOURCE_NAME = "__cpu_usage__";
+
+    /**
+     * A virtual resource identifier for system load statistics (since 1.6.1).
+     */
+    public final static String SYSTEM_LOAD_RESOURCE_NAME = "__system_load__";
+
     /**
      * Global ROOT statistic node that represents the universal parent node.
      */

sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/system/SystemRuleManager.java

@@ -222,6 +222,7 @@ public class SystemRuleManager {
             qps = Double.MAX_VALUE;
 
             highestSystemLoadIsSet = false;
+            highestCpuUsageIsSet = false;
             maxRtIsSet = false;
             maxThreadIsSet = false;
             qpsIsSet = false;

sentinel-core/src/main/java/com/alibaba/csp/sentinel/slots/system/SystemStatusListener.java

@@ -33,8 +33,6 @@ public class SystemStatusListener implements Runnable {
 
     volatile String reason = StringUtil.EMPTY;
 
-    static final int processor = ManagementFactory.getOperatingSystemMXBean().getAvailableProcessors();
-
     public double getSystemAverageLoad() {
         return currentLoad;
     }
@@ -46,10 +44,6 @@ public class SystemStatusListener implements Runnable {
     @Override
     public void run() {
         try {
-            if (!SystemRuleManager.getCheckSystemStatus()) {
-                return;
-            }
-
             OperatingSystemMXBean osBean = ManagementFactory.getPlatformMXBean(OperatingSystemMXBean.class);
             currentLoad = osBean.getSystemLoadAverage();
             /**

sentinel-transport/sentinel-transport-common/src/main/java/com/alibaba/csp/sentinel/command/handler/SendMetricCommandHandler.java

@@ -15,18 +15,22 @@
  */
 package com.alibaba.csp.sentinel.command.handler;
 
+import java.util.ArrayList;
 import java.util.List;
 
+import com.alibaba.csp.sentinel.Constants;
 import com.alibaba.csp.sentinel.command.CommandHandler;
 import com.alibaba.csp.sentinel.command.CommandRequest;
 import com.alibaba.csp.sentinel.command.CommandResponse;
 import com.alibaba.csp.sentinel.command.annotation.CommandMapping;
-import com.alibaba.csp.sentinel.util.PidUtil;
 import com.alibaba.csp.sentinel.config.SentinelConfig;
-import com.alibaba.csp.sentinel.util.StringUtil;
 import com.alibaba.csp.sentinel.node.metric.MetricNode;
 import com.alibaba.csp.sentinel.node.metric.MetricSearcher;
 import com.alibaba.csp.sentinel.node.metric.MetricWriter;
+import com.alibaba.csp.sentinel.slots.system.SystemRuleManager;
+import com.alibaba.csp.sentinel.util.PidUtil;
+import com.alibaba.csp.sentinel.util.StringUtil;
+import com.alibaba.csp.sentinel.util.TimeUtil;
 
 /**
  * Retrieve and aggregate {@link MetricNode} metrics.
@@ -34,7 +38,8 @@ import com.alibaba.csp.sentinel.node.metric.MetricWriter;
  * @author leyou
  * @author Eric Zhao
  */
-@CommandMapping(name = "metric", desc = "get and aggregate metrics, accept param: startTime={startTime}&endTime={endTime}&maxLines={maxLines}&identify={resourceName}")
+@CommandMapping(name = "metric", desc = "get and aggregate metrics, accept param: "
+    + "startTime={startTime}&endTime={endTime}&maxLines={maxLines}&identify={resourceName}")
 public class SendMetricCommandHandler implements CommandHandler<String> {
 
     private MetricSearcher searcher;
@@ -83,9 +88,11 @@ public class SendMetricCommandHandler implements CommandHandler<String> {
         } catch (Exception ex) {
             return CommandResponse.ofFailure(new RuntimeException("Error when retrieving metrics", ex));
         }
-
         if (list == null) {
-            return CommandResponse.ofSuccess("No metrics");
+            list = new ArrayList<>();
+        }
+        if (StringUtil.isBlank(identity)) {
+            addCpuUsageAndLoad(list);
         }
         StringBuilder sb = new StringBuilder();
         for (MetricNode node : list) {
@@ -93,4 +100,43 @@ public class SendMetricCommandHandler implements CommandHandler<String> {
         }
         return CommandResponse.ofSuccess(sb.toString());
     }
+
+    /**
+     * add current cpu usage and load to the metric list.
+     *
+     * @param list metric list, should not be null
+     */
+    private void addCpuUsageAndLoad(List<MetricNode> list) {
+        long time = TimeUtil.currentTimeMillis() / 1000 * 1000;
+        double load = SystemRuleManager.getCurrentSystemAvgLoad();
+        double usage = SystemRuleManager.getCurrentCpuUsage();
+        if (load > 0) {
+            MetricNode loadNode = toNode(load, time, Constants.SYSTEM_LOAD_RESOURCE_NAME);
+            list.add(loadNode);
+        }
+        if (usage > 0) {
+            MetricNode usageNode = toNode(usage, time, Constants.CPU_USAGE_RESOURCE_NAME);
+            list.add(usageNode);
+        }
+    }
+
+    /**
+     * transfer the value to a MetricNode, the value will multiply 10000 then truncate
+     * to long value, and as the {@link MetricNode#passQps}.
+     * <p>
+     * This is an eclectic scheme before we have a standard metric format.
+     * </p>
+     *
+     * @param value    value to save.
+     * @param ts       timestamp
+     * @param resource resource name.
+     * @return a MetricNode represents the value.
+     */
+    private MetricNode toNode(double value, long ts, String resource) {
+        MetricNode node = new MetricNode();
+        node.setPassQps((long)(value * 10000));
+        node.setTimestamp(ts);
+        node.setResource(resource);
+        return node;
+    }
 }