HBASE-29021 When StoreFileTracker is FILE, unable to recognize StoreFileListFile after upgrade from 2.5 to 2.6 (apache#6552)

Signed-off-by: Duo Zhang <zhangduo@apache.org>
Reviewed-by: Viraj Jasani <vjasani@apache.org>
(cherry picked from commit d1a2965)

Author: Jaehui-Lee

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/storefiletracker/StoreFileListFile.java

@@ -84,7 +84,7 @@ class StoreFileListFile {
 
   static final char TRACK_FILE_SEPARATOR = '.';
 
-  static final Pattern TRACK_FILE_PATTERN = Pattern.compile("^f(1|2)\\.\\d+$");
+  static final Pattern TRACK_FILE_PATTERN = Pattern.compile("^f(1|2)(\\.\\d+)?$");
 
   // 16 MB, which is big enough for a tracker file
   private static final int MAX_FILE_SIZE = 16 * 1024 * 1024;
@@ -179,7 +179,9 @@ private NavigableMap<Long, List<Path>> listFiles() throws IOException {
         continue;
       }
       List<String> parts = Splitter.on(TRACK_FILE_SEPARATOR).splitToList(file.getName());
-      map.computeIfAbsent(Long.parseLong(parts.get(1)), k -> new ArrayList<>()).add(file);
+      // For compatibility, set the timestamp to 0 if it is missing in the file name.
+      long timestamp = parts.size() > 1 ? Long.parseLong(parts.get(1)) : 0L;
+      map.computeIfAbsent(timestamp, k -> new ArrayList<>()).add(file);
     }
     return map;
   }

hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/storefiletracker/TestStoreFileListFile.java

@@ -239,4 +239,21 @@ public void testLoadHigherVersion() throws IOException {
     assertEquals("Higher store file list version detected, expected " + StoreFileListFile.VERSION
       + ", got " + (StoreFileListFile.VERSION + 1), error.getMessage());
   }
+
+  @Test
+  public void testLoadOldPatternTrackFiles() throws IOException {
+    FileSystem fs = FileSystem.get(UTIL.getConfiguration());
+    StoreFileList storeFileList =
+      StoreFileList.newBuilder().setTimestamp(EnvironmentEdgeManager.currentTime())
+        .addStoreFile(StoreFileEntry.newBuilder().setName("hehe").setSize(10).build()).build();
+    Path trackFileDir = new Path(testDir, StoreFileListFile.TRACK_FILE_DIR);
+    StoreFileListFile.write(fs, new Path(trackFileDir, StoreFileListFile.TRACK_FILE_PREFIX),
+      storeFileList);
+
+    FileStatus trackerFileStatus = getOnlyTrackerFile(fs);
+    assertEquals(StoreFileListFile.TRACK_FILE_PREFIX, trackerFileStatus.getPath().getName());
+
+    StoreFileList list = storeFileListFile.load(true);
+    assertEquals(1, list.getStoreFileCount());
+  }
 }