[iotdb] branch master updated: Fix the problem of inaccurate GC monitor detection at the beginning and adjusting the alert threshold. (#11297)

[tanxinyu]

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tanxinyu pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/iotdb.git


The following commit(s) were added to refs/heads/master by this push:
     new b61f634b57e Fix the problem of inaccurate GC monitor detection at the 
beginning and adjusting the alert threshold. (#11297)
b61f634b57e is described below

commit b61f634b57e83a65fed0edadacc856f2d134203c
Author: Peng Junzhi <78788603+peng...@users.noreply.github.com>
AuthorDate: Thu Oct 12 21:11:18 2023 -0500

    Fix the problem of inaccurate GC monitor detection at the beginning and 
adjusting the alert threshold. (#11297)
---
 .../src/main/java/org/apache/iotdb/cli/Cli.java    |  1 -
 .../service/metric/JvmGcMonitorMetrics.java        | 35 ++++++++++++++--------
 2 files changed, 23 insertions(+), 13 deletions(-)

diff --git a/iotdb-client/cli/src/main/java/org/apache/iotdb/cli/Cli.java 
b/iotdb-client/cli/src/main/java/org/apache/iotdb/cli/Cli.java
index b65d16ad288..54c7f223991 100644
--- a/iotdb-client/cli/src/main/java/org/apache/iotdb/cli/Cli.java
+++ b/iotdb-client/cli/src/main/java/org/apache/iotdb/cli/Cli.java
@@ -45,7 +45,6 @@ import static org.apache.iotdb.jdbc.Config.IOTDB_ERROR_PREFIX;
 
 /** args[]: -h 127.0.0.1 -p 6667 -u root -pw root */
 public class Cli extends AbstractCli {
-
   private static CommandLine commandLine;
   private static LineReader lineReader;
 
diff --git 
a/iotdb-core/node-commons/src/main/java/org/apache/iotdb/commons/service/metric/JvmGcMonitorMetrics.java
 
b/iotdb-core/node-commons/src/main/java/org/apache/iotdb/commons/service/metric/JvmGcMonitorMetrics.java
index 6624c3047de..db6987bbb3c 100644
--- 
a/iotdb-core/node-commons/src/main/java/org/apache/iotdb/commons/service/metric/JvmGcMonitorMetrics.java
+++ 
b/iotdb-core/node-commons/src/main/java/org/apache/iotdb/commons/service/metric/JvmGcMonitorMetrics.java
@@ -45,9 +45,9 @@ public class JvmGcMonitorMetrics implements IMetricSet {
   // Interval for data collection
   public static final long SLEEP_INTERVAL_MS = TimeUnit.SECONDS.toMillis(5);
   // Max GC time threshold
-  public static final long MAX_GC_TIME_PERCENTAGE = 40L;
-  // The time when IoTDB start running
-  private static long startTime;
+  public static final long MAX_GC_TIME_PERCENTAGE = 30L;
+  // The time when JvmGcMonitorMetrics start running
+  private static long monitorStartTime;
   private static final Logger logger = 
LoggerFactory.getLogger(JvmGcMonitorMetrics.class);
   private final ScheduledExecutorService scheduledGCInfoMonitor =
       IoTDBThreadPoolFactory.newSingleThreadScheduledExecutor(
@@ -87,9 +87,11 @@ public class JvmGcMonitorMetrics implements IMetricSet {
         curData,
         GcData::getGcTimePercentage);
 
-    startTime = System.currentTimeMillis();
+    monitorStartTime = System.currentTimeMillis();
+    // Set start time's accumulated GC Time
+    curData.setAccumulatedGcTime(getTotalGCTime());
     // current collect time: startTime + start delay(50ms)
-    gcDataBuf[startIdx].setValues(startTime + 
TimeUnit.MILLISECONDS.toMillis(50), 0);
+    gcDataBuf[startIdx].setValues(monitorStartTime + 
TimeUnit.MILLISECONDS.toMillis(50), 0);
     scheduledGcMonitorFuture =
         ScheduledExecutorUtil.safelyScheduleWithFixedDelay(
             scheduledGCInfoMonitor,
@@ -112,21 +114,26 @@ public class JvmGcMonitorMetrics implements IMetricSet {
 
   private void scheduledMonitoring() {
     calculateGCTimePercentageWithinObservedInterval();
-    if (alertHandler != null && curData.gcTimePercentage.get() > 
MAX_GC_TIME_PERCENTAGE) {
+    if (alertHandler != null && curData.getGcTimePercentage() > 
MAX_GC_TIME_PERCENTAGE) {
       alertHandler.alert(curData.clone());
     }
   }
 
-  private void calculateGCTimePercentageWithinObservedInterval() {
-    long prevTotalGcTime = curData.getAccumulatedGcTime();
+  private long getTotalGCTime() {
     long totalGcTime = 0;
     for (GarbageCollectorMXBean gcBean : 
ManagementFactory.getGarbageCollectorMXBeans()) {
       totalGcTime += gcBean.getCollectionTime();
     }
-    long gcTimeWithinSleepInterval = totalGcTime - prevTotalGcTime;
+    return totalGcTime;
+  }
+
+  private void calculateGCTimePercentageWithinObservedInterval() {
+    long prevTotalGcTime = curData.getAccumulatedGcTime();
+    long totalGcTime = getTotalGCTime();
 
+    long gcTimeWithinSleepInterval = totalGcTime - prevTotalGcTime;
     long curTime = System.currentTimeMillis();
-    long gcMonitorRunTime = curTime - startTime;
+    long gcMonitorRunTime = curTime - monitorStartTime;
 
     endIdx = (endIdx + 1) % bufSize;
     gcDataBuf[endIdx].setValues(curTime, gcTimeWithinSleepInterval);
@@ -182,7 +189,7 @@ public class JvmGcMonitorMetrics implements IMetricSet {
      * @return current observation window time, millisecond.
      */
     public long getCurrentObsWindowTs() {
-      return Math.min(timestamp.get() - startTime, timestamp.get() - 
startObsWindowTs.get());
+      return Math.min(timestamp.get() - monitorStartTime, timestamp.get() - 
startObsWindowTs.get());
     }
 
     /**
@@ -200,7 +207,7 @@ public class JvmGcMonitorMetrics implements IMetricSet {
      * @return the actual start timestamp of the obs window.
      */
     public long getStartObsWindowTs() {
-      return Math.max(startObsWindowTs.get(), startTime);
+      return Math.max(startObsWindowTs.get(), monitorStartTime);
     }
 
     /**
@@ -231,6 +238,10 @@ public class JvmGcMonitorMetrics implements IMetricSet {
       return gcTimePercentage.get();
     }
 
+    private void setAccumulatedGcTime(long accumulatedGcTime) {
+      this.accumulatedGcTime.set(accumulatedGcTime);
+    }
+
     private synchronized void update(
         long inTimestamp,
         long inStartObsWindowTs,