HDFS-16872. Fix log throttling by declaring LogThrottlingHelper as static members (#5246)

Co-authored-by: Chengbing Liu <liuchengbing@qiyi.com>
Signed-off-by: Erik Krogen <xkrogen@apache.org>

(cherry picked from commit 4cf304de45)

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/log/LogThrottlingHelper.java

@@ -65,7 +65,7 @@ import org.apache.hadoop.util.Timer;
  * <p>This class can also be used to coordinate multiple logging points; see
  * {@link #record(String, long, double...)} for more details.
  *
- * <p>This class is not thread-safe.
+ * <p>This class is thread-safe.
  */
 public class LogThrottlingHelper {
 
@@ -192,7 +192,7 @@ public class LogThrottlingHelper {
    * @return A LogAction indicating whether or not the caller should write to
    *         its log.
    */
-  public LogAction record(double... values) {
+  public synchronized LogAction record(double... values) {
     return record(DEFAULT_RECORDER_NAME, timer.monotonicNow(), values);
   }
 
@@ -244,7 +244,7 @@ public class LogThrottlingHelper {
    *
    * @see #record(double...)
    */
-  public LogAction record(String recorderName, long currentTimeMs,
+  public synchronized LogAction record(String recorderName, long currentTimeMs,
       double... values) {
     if (primaryRecorderName == null) {
       primaryRecorderName = recorderName;
@@ -287,7 +287,7 @@ public class LogThrottlingHelper {
    * @param idx The index value.
    * @return The summary information.
    */
-  public SummaryStatistics getCurrentStats(String recorderName, int idx) {
+  public synchronized SummaryStatistics getCurrentStats(String recorderName, int idx) {
     LoggingAction currentLog = currentLogs.get(recorderName);
     if (currentLog != null) {
       return currentLog.getStats(idx);
@@ -314,6 +314,13 @@ public class LogThrottlingHelper {
     }
   }
 
+  @VisibleForTesting
+  public synchronized void reset() {
+    primaryRecorderName = null;
+    currentLogs.clear();
+    lastLogTimestampMs = Long.MIN_VALUE;
+  }
+
   /**
    * A standard log action which keeps track of all of the values which have
    * been logged. This is also used for internal bookkeeping via its private

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSEditLogLoader.java

@@ -132,7 +132,8 @@ public class FSEditLogLoader {
   /** Limit logging about edit loading to every 5 seconds max. */
   @VisibleForTesting
   static final long LOAD_EDIT_LOG_INTERVAL_MS = 5000;
-  private final LogThrottlingHelper loadEditsLogHelper =
+  @VisibleForTesting
+  static final LogThrottlingHelper LOAD_EDITS_LOG_HELPER =
       new LogThrottlingHelper(LOAD_EDIT_LOG_INTERVAL_MS);
 
   private final FSNamesystem fsNamesys;
@@ -173,7 +174,7 @@ public class FSEditLogLoader {
     fsNamesys.writeLock();
     try {
       long startTime = timer.monotonicNow();
-      LogAction preLogAction = loadEditsLogHelper.record("pre", startTime);
+      LogAction preLogAction = LOAD_EDITS_LOG_HELPER.record("pre", startTime);
       if (preLogAction.shouldLog()) {
         FSImage.LOG.info("Start loading edits file " + edits.getName()
             + " maxTxnsToRead = " + maxTxnsToRead +
@@ -182,7 +183,7 @@ public class FSEditLogLoader {
       long numEdits = loadEditRecords(edits, false, expectedStartingTxId,
           maxTxnsToRead, startOpt, recovery);
       long endTime = timer.monotonicNow();
-      LogAction postLogAction = loadEditsLogHelper.record("post", endTime,
+      LogAction postLogAction = LOAD_EDITS_LOG_HELPER.record("post", endTime,
           numEdits, edits.length(), endTime - startTime);
       if (postLogAction.shouldLog()) {
         FSImage.LOG.info("Loaded {} edits file(s) (the last named {}) of " +

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/RedundantEditLogInputStream.java

@@ -47,7 +47,7 @@ class RedundantEditLogInputStream extends EditLogInputStream {
 
   /** Limit logging about fast forwarding the stream to every 5 seconds max. */
   private static final long FAST_FORWARD_LOGGING_INTERVAL_MS = 5000;
-  private final LogThrottlingHelper fastForwardLoggingHelper =
+  private static final LogThrottlingHelper FAST_FORWARD_LOGGING_HELPER =
       new LogThrottlingHelper(FAST_FORWARD_LOGGING_INTERVAL_MS);
 
   /**
@@ -182,7 +182,7 @@ class RedundantEditLogInputStream extends EditLogInputStream {
       case SKIP_UNTIL:
        try {
           if (prevTxId != HdfsServerConstants.INVALID_TXID) {
-            LogAction logAction = fastForwardLoggingHelper.record();
+            LogAction logAction = FAST_FORWARD_LOGGING_HELPER.record();
             if (logAction.shouldLog()) {
               LOG.info("Fast-forwarding stream '" + streams[curIdx].getName() +
                   "' to transaction ID " + (prevTxId + 1) +

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFSEditLogLoader.java

@@ -807,12 +807,13 @@ public class TestFSEditLogLoader {
   }
 
   @Test
-  public void setLoadFSEditLogThrottling() throws Exception {
+  public void testLoadFSEditLogThrottling() throws Exception {
     FSNamesystem namesystem = mock(FSNamesystem.class);
     namesystem.dir = mock(FSDirectory.class);
 
     FakeTimer timer = new FakeTimer();
     FSEditLogLoader loader = new FSEditLogLoader(namesystem, 0, timer);
+    FSEditLogLoader.LOAD_EDITS_LOG_HELPER.reset();
 
     LogCapturer capture = LogCapturer.captureLogs(FSImage.LOG);
     loader.loadFSEdits(getFakeEditLogInputStream(1, 10), 1);