HBASE-5545 region can't be opened for a long time. Because the creating File failed. (Ram)

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1327677 13f79535-47bb-0310-9956-ffa450edef68

src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java

@@ -729,6 +729,15 @@ public class HRegion implements HeapSize { // , Writable{
 
     // and then create the file
     Path tmpPath = new Path(getTmpDir(), REGIONINFO_FILE);
+    
+    // if datanode crashes or if the RS goes down just before the close is called while trying to
+    // close the created regioninfo file in the .tmp directory then on next
+    // creation we will be getting AlreadyCreatedException.
+    // Hence delete and create the file if exists.
+    if (FSUtils.isExists(fs, tmpPath)) {
+      FSUtils.delete(fs, tmpPath, true);
+    }
+    
     FSDataOutputStream out = FSUtils.create(fs, tmpPath, perms);
 
     try {

src/main/java/org/apache/hadoop/hbase/util/FSUtils.java

@@ -1016,4 +1016,30 @@ public abstract class FSUtils {
     if (status == null || status.length < 1) return null;
     return status;
   }
+  
+  /**
+   * Calls fs.delete() and returns the value returned by the fs.delete()
+   * 
+   * @param fs
+   * @param path
+   * @param recursive
+   * @return
+   * @throws IOException
+   */
+  public static boolean delete(final FileSystem fs, final Path path, final boolean recursive)
+      throws IOException {
+    return fs.delete(path, recursive);
+  }
+
+  /**
+   * Calls fs.exists(). Checks if the specified path exists
+   * 
+   * @param fs
+   * @param path
+   * @return
+   * @throws IOException
+   */
+  public static boolean isExists(final FileSystem fs, final Path path) throws IOException {
+    return fs.exists(path);
+  }
 }

src/test/java/org/apache/hadoop/hbase/util/TestFSUtils.java

@@ -186,6 +186,35 @@ public class TestFSUtils {
     }
   }
   
+  @Test
+  public void testDeleteAndExists() throws Exception {
+    Configuration conf = HBaseConfiguration.create();
+    conf.setBoolean(HConstants.ENABLE_DATA_FILE_UMASK, true);
+    FileSystem fs = FileSystem.get(conf);
+    FsPermission perms = FSUtils.getFilePermissions(fs, conf, HConstants.DATA_FILE_UMASK_KEY);
+    // then that the correct file is created
+    String file = UUID.randomUUID().toString();
+    Path p = new Path("temptarget" + File.separator + file);
+    Path p1 = new Path("temppath" + File.separator + file);
+    try {
+      FSDataOutputStream out = FSUtils.create(fs, p, perms);
+      out.close();
+      assertTrue("The created file should be present", FSUtils.isExists(fs, p));
+      // delete the file with recursion as false. Only the file will be deleted.
+      FSUtils.delete(fs, p, false);
+      // Create another file
+      FSDataOutputStream out1 = FSUtils.create(fs, p1, perms);
+      out1.close();
+      // delete the file with recursion as false. Still the file only will be deleted
+      FSUtils.delete(fs, p1, true);
+      assertFalse("The created file should be present", FSUtils.isExists(fs, p1));
+      // and then cleanup
+    } finally {
+      FSUtils.delete(fs, p, true);
+      FSUtils.delete(fs, p1, true);
+    }
+  }
+
   @org.junit.Rule
   public org.apache.hadoop.hbase.ResourceCheckerJUnitRule cu =
     new org.apache.hadoop.hbase.ResourceCheckerJUnitRule();