Fix FLUME-3233: only use inode to identify files then taildirSource will support file rename/rotation

flume-ng-sources/flume-taildir-source/src/main/java/org/apache/flume/source/taildir/ReliableTaildirEventReader.java

@@ -60,14 +60,17 @@ public class ReliableTaildirEventReader implements ReliableEventReader {
   private boolean committed = true;
   private final boolean annotateFileName;
   private final String fileNameHeader;
+  private boolean inodeOnly = false;
 
   /**
    * Create a ReliableTaildirEventReader to watch the given directory.
    */
   private ReliableTaildirEventReader(Map<String, String> filePaths,
       Table<String, String, String> headerTable, String positionFilePath,
       boolean skipToEnd, boolean addByteOffset, boolean cachePatternMatching,
-      boolean annotateFileName, String fileNameHeader) throws IOException {
+      boolean annotateFileName, String fileNameHeader, boolean inodeOnly)
+      throws IOException {
+    this.inodeOnly = inodeOnly;
     // Sanity checks
     Preconditions.checkNotNull(filePaths);
     Preconditions.checkNotNull(positionFilePath);
@@ -134,7 +137,13 @@ public void loadPositionFile(String filePath) {
               + "inode: " + inode + ", pos: " + pos + ", path: " + path);
         }
         TailFile tf = tailFiles.get(inode);
-        if (tf != null && tf.updatePos(path, inode, pos)) {
+        boolean isLoaded = false;
+        if (inodeOnly) {
+          isLoaded = tf != null && tf.updatePosAndPath(path, inode, pos);
+        } else {
+          isLoaded = tf != null && tf.updatePos(path, inode, pos);
+        }
+        if (isLoaded) {
           tailFiles.put(inode, tf);
         } else {
           logger.info("Missing file: " + path + ", inode: " + inode + ", pos: " + pos);
@@ -251,7 +260,14 @@ public List<Long> updateTailFiles(boolean skipToEnd) throws IOException {
           continue;
         }
         TailFile tf = tailFiles.get(inode);
-        if (tf == null || !tf.getPath().equals(f.getAbsolutePath())) {
+
+        boolean isNewFile = false;
+        if (inodeOnly) {
+          isNewFile = tf == null;
+        } else {
+          isNewFile = tf == null || !tf.getPath().equals(f.getAbsolutePath());
+        }
+        if (isNewFile) {
           long startPos = skipToEnd ? f.length() : 0;
           tf = openFile(f, headers, inode, startPos);
         } else {
@@ -267,6 +283,7 @@ public List<Long> updateTailFiles(boolean skipToEnd) throws IOException {
             }
           }
           tf.setNeedTail(updated);
+          tf.setPath(f.getAbsolutePath());
         }
         tailFiles.put(inode, tf);
         updatedInodes.add(inode);
@@ -308,6 +325,8 @@ public static class Builder {
             TaildirSourceConfigurationConstants.DEFAULT_FILE_HEADER;
     private String fileNameHeader =
             TaildirSourceConfigurationConstants.DEFAULT_FILENAME_HEADER_KEY;
+    private Boolean inodeOnly =
+            TaildirSourceConfigurationConstants.DEFAULT_INODE_ONLY;
 
     public Builder filePaths(Map<String, String> filePaths) {
       this.filePaths = filePaths;
@@ -349,10 +368,15 @@ public Builder fileNameHeader(String fileNameHeader) {
       return this;
     }
 
+    public Builder inodeOnly(boolean inodeOnly) {
+      this.inodeOnly = inodeOnly;
+      return this;
+    }
+
     public ReliableTaildirEventReader build() throws IOException {
       return new ReliableTaildirEventReader(filePaths, headerTable, positionFilePath, skipToEnd,
                                             addByteOffset, cachePatternMatching,
-                                            annotateFileName, fileNameHeader);
+                                            annotateFileName, fileNameHeader, inodeOnly);
     }
   }
 

flume-ng-sources/flume-taildir-source/src/main/java/org/apache/flume/source/taildir/TailFile.java

@@ -43,7 +43,7 @@ public class TailFile {
   private static final int NEED_READING = -1;
 
   private RandomAccessFile raf;
-  private final String path;
+  private String path;
   private final long inode;
   private long pos;
   private long lastUpdated;
@@ -107,6 +107,10 @@ public void setPos(long pos) {
     this.pos = pos;
   }
 
+  public void setPath(String path) {
+    this.path = path;
+  }
+
   public void setLastUpdated(long lastUpdated) {
     this.lastUpdated = lastUpdated;
   }
@@ -128,6 +132,19 @@ public boolean updatePos(String path, long inode, long pos) throws IOException {
     }
     return false;
   }
+
+  public boolean updatePosAndPath(String path, long inode, long pos) throws IOException {
+    if (this.inode == inode) {
+      setPos(pos);
+      setPath(path);
+      updateFilePos(pos);
+      logger.info("Updated position and path, file: " + path + ", inode: " + inode +
+              ", pos: " + pos);
+      return true;
+    }
+    return false;
+  }
+
   public void updateFilePos(long pos) throws IOException {
     raf.seek(pos);
     lineReadPos = pos;

flume-ng-sources/flume-taildir-source/src/main/java/org/apache/flume/source/taildir/TaildirSource.java

@@ -88,6 +88,7 @@ public class TaildirSource extends AbstractSource implements
   private boolean fileHeader;
   private String fileHeaderKey;
   private Long maxBatchCount;
+  private boolean inodeOnly;
 
   @Override
   public synchronized void start() {
@@ -102,6 +103,7 @@ public synchronized void start() {
           .cachePatternMatching(cachePatternMatching)
           .annotateFileName(fileHeader)
           .fileNameHeader(fileHeaderKey)
+          .inodeOnly(inodeOnly)
           .build();
     } catch (IOException e) {
       throw new FlumeException("Error instantiating ReliableTaildirEventReader", e);
@@ -187,6 +189,7 @@ public synchronized void configure(Context context) {
     fileHeaderKey = context.getString(FILENAME_HEADER_KEY,
             DEFAULT_FILENAME_HEADER_KEY);
     maxBatchCount = context.getLong(MAX_BATCH_COUNT, DEFAULT_MAX_BATCH_COUNT);
+    inodeOnly = context.getBoolean(INODE_ONLY, DEFAULT_INODE_ONLY);
     if (maxBatchCount <= 0) {
       maxBatchCount = DEFAULT_MAX_BATCH_COUNT;
       logger.warn("Invalid maxBatchCount specified, initializing source "

flume-ng-sources/flume-taildir-source/src/main/java/org/apache/flume/source/taildir/TaildirSourceConfigurationConstants.java

@@ -67,4 +67,8 @@ public class TaildirSourceConfigurationConstants {
   /** The max number of batch reads from a file in one loop */
   public static final String MAX_BATCH_COUNT = "maxBatchCount";
   public static final Long DEFAULT_MAX_BATCH_COUNT = Long.MAX_VALUE;
+
+  /** Whether to support file rotation in case it only checks inode nor both inode and file name */
+  public static final String INODE_ONLY = "inodeOnly";
+  public static final Boolean DEFAULT_INODE_ONLY = false;
 }