[Feature] Add CPU usage checking support in system protection rule

pom.xml

@@ -50,8 +50,8 @@
 
         <!-- Build -->
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <java.source.version>1.6</java.source.version>
-        <java.target.version>1.6</java.target.version>
+        <java.source.version>1.7</java.source.version>
+        <java.target.version>1.7</java.target.version>
         <java.encoding>UTF-8</java.encoding>
         <maven.compiler.version>3.8.0</maven.compiler.version>
         <maven.surefire.version>2.22.1</maven.surefire.version>

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

@@ -34,6 +34,7 @@
  * </p>
  *
  * @author jialiang.linjl
+ * @author Carpenter Lee
  * @see SystemRuleManager
  */
 public class SystemRule extends AbstractRule {
@@ -42,6 +43,10 @@ public class SystemRule extends AbstractRule {
      * negative value means no threshold checking.
      */
     private double highestSystemLoad = -1;
+    /**
+     * cpu usage, between [0, 1]
+     */
+    private double highestCpuUsage = -1;
     private double qps = -1;
     private long avgRt = -1;
     private long maxThread = -1;
@@ -110,6 +115,24 @@ public void setHighestSystemLoad(double highestSystemLoad) {
         this.highestSystemLoad = highestSystemLoad;
     }
 
+    /**
+     * Get highest cpu usage. Cpu usage is between [0, 1]
+     *
+     * @return highest cpu usage
+     */
+    public double getHighestCpuUsage() {
+        return highestCpuUsage;
+    }
+
+    /**
+     * set highest cpu usage. Cpu usage is between [0, 1]
+     *
+     * @param highestCpuUsage the value to set.
+     */
+    public void setHighestCpuUsage(double highestCpuUsage) {
+        this.highestCpuUsage = highestCpuUsage;
+    }
+
     @Override
     public boolean passCheck(Context context, DefaultNode node, int count, Object... args) {
         return true;
@@ -132,6 +155,9 @@ public boolean equals(Object o) {
         if (Double.compare(that.highestSystemLoad, highestSystemLoad) != 0) {
             return false;
         }
+        if (Double.compare(that.highestCpuUsage, highestCpuUsage) != 0) {
+            return false;
+        }
 
         if (Double.compare(that.qps, qps) != 0) {
             return false;
@@ -150,6 +176,9 @@ public int hashCode() {
         temp = Double.doubleToLongBits(highestSystemLoad);
         result = 31 * result + (int)(temp ^ (temp >>> 32));
 
+        temp = Double.doubleToLongBits(highestCpuUsage);
+        result = 31 * result + (int)(temp ^ (temp >>> 32));
+
         temp = Double.doubleToLongBits(qps);
         result = 31 * result + (int)(temp ^ (temp >>> 32));
 
@@ -162,6 +191,7 @@ public int hashCode() {
     public String toString() {
         return "SystemRule{" +
             "highestSystemLoad=" + highestSystemLoad +
+            ", highestCpuUsage=" + highestCpuUsage +
             ", qps=" + qps +
             ", avgRt=" + avgRt +
             ", maxThread=" + maxThread +

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

@@ -66,13 +66,18 @@
 public class SystemRuleManager {
 
     private static volatile double highestSystemLoad = Double.MAX_VALUE;
+    /**
+     * cpu usage, between [0, 1]
+     */
+    private static volatile double highestCpuUsage = Double.MAX_VALUE;
     private static volatile double qps = Double.MAX_VALUE;
     private static volatile long maxRt = Long.MAX_VALUE;
     private static volatile long maxThread = Long.MAX_VALUE;
     /**
      * mark whether the threshold are set by user.
      */
     private static volatile boolean highestSystemLoadIsSet = false;
+    private static volatile boolean highestCpuUsageIsSet = false;
     private static volatile boolean qpsIsSet = false;
     private static volatile boolean maxRtIsSet = false;
     private static volatile boolean maxThreadIsSet = false;
@@ -134,6 +139,12 @@ public static List<SystemRule> getRules() {
             result.add(loadRule);
         }
 
+        if (highestCpuUsageIsSet) {
+            SystemRule rule = new SystemRule();
+            rule.setHighestCpuUsage(highestCpuUsage);
+            result.add(rule);
+        }
+
         if (maxRtIsSet) {
             SystemRule rtRule = new SystemRule();
             rtRule.setAvgRt(maxRt);
@@ -185,16 +196,26 @@ public void configUpdate(List<SystemRule> rules) {
                 checkSystemStatus.set(false);
             }
 
-
-            RecordLog.info(String.format("[SystemRuleManager] Current system check status: %s, highestSystemLoad: "
-                + highestSystemLoad + ", " + "maxRt: %d, maxThread: %d, maxQps: " + qps, checkSystemStatus.get(), maxRt, maxThread));
+            RecordLog.info(String.format("[SystemRuleManager] Current system check status: %s, "
+                    + "highestSystemLoad: %e, "
+                    + "highestCpuUsage: %e, "
+                    + "maxRt: %d, "
+                    + "maxThread: %d, "
+                    + "maxQps: %e",
+                checkSystemStatus.get(),
+                highestSystemLoad,
+                highestCpuUsage,
+                maxRt,
+                maxThread,
+                qps));
         }
 
         protected void restoreSetting() {
             checkSystemStatus.set(false);
 
             // should restore changes
             highestSystemLoad = Double.MAX_VALUE;
+            highestCpuUsage = Double.MAX_VALUE;
             maxRt = Long.MAX_VALUE;
             maxThread = Long.MAX_VALUE;
             qps = Double.MAX_VALUE;
@@ -229,6 +250,12 @@ public static void loadSystemConf(SystemRule rule) {
             checkStatus = true;
         }
 
+        if (rule.getHighestCpuUsage() >= 0) {
+            highestCpuUsage = Math.min(highestCpuUsage, rule.getHighestCpuUsage());
+            highestCpuUsageIsSet = true;
+            checkStatus = true;
+        }
+
         if (rule.getAvgRt() >= 0) {
             maxRt = Math.min(maxRt, rule.getAvgRt());
             maxRtIsSet = true;
@@ -284,17 +311,34 @@ public static void checkSystem(ResourceWrapper resourceWrapper) throws BlockExce
             throw new SystemBlockException(resourceWrapper.getName(), "rt");
         }
 
-        // BBR algorithm.
+        // load. BBR algorithm.
         if (highestSystemLoadIsSet && getCurrentSystemAvgLoad() > highestSystemLoad) {
-            if (currentThread > 1 &&
-                currentThread > Constants.ENTRY_NODE.maxSuccessQps() * Constants.ENTRY_NODE.minRt() / 1000) {
+            if (!checkBbr(currentThread)) {
                 throw new SystemBlockException(resourceWrapper.getName(), "load");
             }
         }
 
+        // cpu usage
+        if (highestCpuUsageIsSet && getCurrentCpuUsage() > highestCpuUsage) {
+            if (!checkBbr(currentThread)) {
+                throw new SystemBlockException(resourceWrapper.getName(), "cpu");
+            }
+        }
+    }
+
+    private static boolean checkBbr(int currentThread) {
+        if (currentThread > 1 &&
+            currentThread > Constants.ENTRY_NODE.maxSuccessQps() * Constants.ENTRY_NODE.minRt() / 1000) {
+            return false;
+        }
+        return true;
     }
 
     public static double getCurrentSystemAvgLoad() {
         return statusListener.getSystemAverageLoad();
     }
+
+    public static double getCurrentCpuUsage() {
+        return statusListener.getCpuUsage();
+    }
 }

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

@@ -16,18 +16,20 @@
 package com.alibaba.csp.sentinel.slots.system;
 
 import java.lang.management.ManagementFactory;
-import java.lang.management.OperatingSystemMXBean;
 
+import com.alibaba.csp.sentinel.Constants;
 import com.alibaba.csp.sentinel.log.RecordLog;
 import com.alibaba.csp.sentinel.util.StringUtil;
-import com.alibaba.csp.sentinel.Constants;
+
+import com.sun.management.OperatingSystemMXBean;
 
 /**
  * @author jialiang.linjl
  */
 public class SystemStatusListener implements Runnable {
 
     volatile double currentLoad = -1;
+    volatile double currentCpuUsage = -1;
 
     volatile String reason = StringUtil.EMPTY;
 
@@ -37,20 +39,33 @@ public double getSystemAverageLoad() {
         return currentLoad;
     }
 
+    public double getCpuUsage() {
+        return currentCpuUsage;
+    }
+
     @Override
     public void run() {
         try {
             if (!SystemRuleManager.getCheckSystemStatus()) {
                 return;
             }
 
-            // system average load
-            OperatingSystemMXBean operatingSystemMXBean = ManagementFactory.getOperatingSystemMXBean();
-            currentLoad = operatingSystemMXBean.getSystemLoadAverage();
+            OperatingSystemMXBean osBean = ManagementFactory.getPlatformMXBean(OperatingSystemMXBean.class);
+            currentLoad = osBean.getSystemLoadAverage();
+            /**
+             * Java Doc copied from {@link OperatingSystemMXBean#getSystemCpuLoad()}:</br>
+             * Returns the "recent cpu usage" for the whole system. This value is a double in the [0.0,1.0] interval.
+             * A value of 0.0 means that all CPUs were idle during the recent period of time observed, while a value
+             * of 1.0 means that all CPUs were actively running 100% of the time during the recent period being
+             * observed. All values betweens 0.0 and 1.0 are possible depending of the activities going on in the
+             * system. If the system recent cpu usage is not available, the method returns a negative value.
+             */
+            currentCpuUsage = osBean.getSystemCpuLoad();
 
             StringBuilder sb = new StringBuilder();
             if (currentLoad > SystemRuleManager.getHighestSystemLoad()) {
                 sb.append("load:").append(currentLoad).append(";");
+                sb.append("cpu:").append(currentCpuUsage).append(";");
                 sb.append("qps:").append(Constants.ENTRY_NODE.passQps()).append(";");
                 sb.append("rt:").append(Constants.ENTRY_NODE.avgRt()).append(";");
                 sb.append("thread:").append(Constants.ENTRY_NODE.curThreadNum()).append(";");

sentinel-demo/sentinel-demo-basic/src/main/java/com/alibaba/csp/sentinel/demo/system/SystemGuardDemo.java

@@ -91,6 +91,8 @@ private static void initSystemRule() {
         SystemRule rule = new SystemRule();
         // max load is 3
         rule.setHighestSystemLoad(3.0);
+        // max cpu usage is 60%
+        rule.setHighestCpuUsage(0.6);
         // max avg rt of all request is 10 ms
         rule.setAvgRt(10);
         // max total qps is 20