HDFS-11292. log lastWrittenTxId etc info in logSyncAll. Contributed by Yongjun Zhang.

(cherry picked from commit 603cbcd513a74c29e0e4ec9dc181ff08887d64a4)

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

@@ -597,7 +597,15 @@ public class FSEditLog implements LogsPurgeable {
    */
   void logSyncAll() {
     // Make sure we're synced up to the most recent transaction ID.
-    logSync(getLastWrittenTxId());
+    long lastWrittenTxId = getLastWrittenTxId();
+    LOG.info("logSyncAll toSyncToTxId=" + lastWrittenTxId
+        + " lastSyncedTxid=" + synctxid
+        + " mostRecentTxid=" + txid);
+    logSync(lastWrittenTxId);
+    lastWrittenTxId = getLastWrittenTxId();
+    LOG.info("Done logSyncAll lastWrittenTxId=" + lastWrittenTxId
+        + " lastSyncedTxid=" + synctxid
+        + " mostRecentTxid=" + txid);
   }
 
   /**
@@ -1325,7 +1333,8 @@ public class FSEditLog implements LogsPurgeable {
    * Transitions from IN_SEGMENT state to BETWEEN_LOG_SEGMENTS state.
    */
   public synchronized void endCurrentLogSegment(boolean writeEndTxn) {
-    LOG.info("Ending log segment " + curSegmentTxId);
+    LOG.info("Ending log segment " + curSegmentTxId +
+        ", " + getLastWrittenTxId());
     Preconditions.checkState(isSegmentOpen(),
         "Bad state: %s", state);
     
@@ -1339,7 +1348,10 @@ public class FSEditLog implements LogsPurgeable {
     printStatistics(true);
     
     final long lastTxId = getLastWrittenTxId();
-    
+    final long lastSyncedTxId = getSyncTxId();
+    Preconditions.checkArgument(lastTxId == lastSyncedTxId,
+        "LastWrittenTxId %s is expected to be the same as lastSyncedTxId %s",
+        lastTxId, lastSyncedTxId);
     try {
       journalSet.finalizeLogSegment(curSegmentTxId, lastTxId);
       editLogStream = null;