Update UI, revert #2952 and fix JVM CPU usage again (#2961)

* Update UI.

* Fix CPU time again

* Update UI.

apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/jvm/cpu/CPUMetricsAccessor.java

@@ -22,8 +22,8 @@ package org.apache.skywalking.apm.agent.core.jvm.cpu;
 import org.apache.skywalking.apm.network.common.CPU;
 
 /**
- * The unit of CPU usage is 1/10000.
- * The backend is using `avg` func directly, and query for percentage requires this unit.
+ * The unit of CPU usage is 1/10000. The backend is using `avg` func directly, and query for percentage requires this
+ * unit.
  *
  * @author wusheng
  */
@@ -38,7 +38,7 @@ public abstract class CPUMetricsAccessor {
 
     protected void init() {
         lastCPUTimeNs = this.getCpuTime();
-        this.lastSampleTimeNs = System.nanoTime();
+        lastSampleTimeNs = System.nanoTime();
     }
 
     protected abstract long getCpuTime();
@@ -48,7 +48,12 @@ public abstract class CPUMetricsAccessor {
         long cpuCost = cpuTime - lastCPUTimeNs;
         long now = System.nanoTime();
 
-        CPU.Builder cpuBuilder = CPU.newBuilder();
-        return cpuBuilder.setUsagePercent(cpuCost * 1.0d / ((now - lastSampleTimeNs) * cpuCoreNum) * 10000).build();
+        try {
+            CPU.Builder cpuBuilder = CPU.newBuilder();
+            return cpuBuilder.setUsagePercent(cpuCost * 1.0d / ((now - lastSampleTimeNs) * cpuCoreNum) * 100).build();
+        } finally {
+            lastCPUTimeNs = cpuTime;
+            lastSampleTimeNs = now;
+        }
     }
 }

skywalking-ui @ 1ace261b

-Subproject commit d48cc15b3a7260ff62a79dab3699db32a6889b3f
+Subproject commit 1ace261b8bbef0ac8b799106fb0a8a362571153b