Java HConstants.CLUSTER_ID_FILE_NAME屬性代碼示例

/**
 * Checks that a cluster ID file exists in the HBase root directory
 * @param fs the root directory FileSystem
 * @param rootdir the HBase root directory in HDFS
 * @param wait how long to wait between retries
 * @return <code>true</code> if the file exists, otherwise <code>false</code>
 * @throws IOException if checking the FileSystem fails
 */
public static boolean checkClusterIdExists(FileSystem fs, Path rootdir,
    int wait) throws IOException {
  while (true) {
    try {
      Path filePath = new Path(rootdir, HConstants.CLUSTER_ID_FILE_NAME);
      return fs.exists(filePath);
    } catch (IOException ioe) {
      if (wait > 0) {
        LOG.warn("Unable to check cluster ID file in " + rootdir.toString() +
            ", retrying in "+wait+"msec: "+StringUtils.stringifyException(ioe));
        try {
          Thread.sleep(wait);
        } catch (InterruptedException e) {
          throw (InterruptedIOException)new InterruptedIOException().initCause(e);
        }
      } else {
        throw ioe;
      }
    }
  }
}
 

@Test
public void testRewritingClusterIdToPB() throws Exception {
  TEST_UTIL.startMiniZKCluster();
  TEST_UTIL.startMiniDFSCluster(1);
  TEST_UTIL.createRootDir();
  TEST_UTIL.getConfiguration().setBoolean("hbase.replication", true);
  Path rootDir = FSUtils.getRootDir(TEST_UTIL.getConfiguration());
  FileSystem fs = rootDir.getFileSystem(TEST_UTIL.getConfiguration());
  Path filePath = new Path(rootDir, HConstants.CLUSTER_ID_FILE_NAME);
  FSDataOutputStream s = null;
  try {
    s = fs.create(filePath);
    s.writeUTF(UUID.randomUUID().toString());
  } finally {
    if (s != null) {
      s.close();
    }
  }
  TEST_UTIL.startMiniHBaseCluster(1, 1);
  HMaster master = TEST_UTIL.getHBaseCluster().getMaster();
  assertEquals(1, master.getServerManager().getOnlineServersList().size());
}
 

/**
 * Writes a new unique identifier for this cluster to the "hbase.id" file
 * in the HBase root directory
 * @param fs the root directory FileSystem
 * @param rootdir the path to the HBase root directory
 * @param clusterId the unique identifier to store
 * @param wait how long (in milliseconds) to wait between retries
 * @throws IOException if writing to the FileSystem fails and no wait value
 */
public static void setClusterId(FileSystem fs, Path rootdir, ClusterId clusterId,
    int wait) throws IOException {
  while (true) {
    try {
      Path idFile = new Path(rootdir, HConstants.CLUSTER_ID_FILE_NAME);
      Path tempIdFile = new Path(rootdir, HConstants.HBASE_TEMP_DIRECTORY +
        Path.SEPARATOR + HConstants.CLUSTER_ID_FILE_NAME);
      // Write the id file to a temporary location
      FSDataOutputStream s = fs.create(tempIdFile);
      try {
        s.write(clusterId.toByteArray());
        s.close();
        s = null;
        // Move the temporary file to its normal location. Throw an IOE if
        // the rename failed
        if (!fs.rename(tempIdFile, idFile)) {
          throw new IOException("Unable to move temp version file to " + idFile);
        }
      } finally {
        // Attempt to close the stream if still open on the way out
        try {
          if (s != null) s.close();
        } catch (IOException ignore) { }
      }
      if (LOG.isDebugEnabled()) {
        LOG.debug("Created cluster ID file at " + idFile.toString() + " with ID: " + clusterId);
      }
      return;
    } catch (IOException ioe) {
      if (wait > 0) {
        LOG.warn("Unable to create cluster ID file in " + rootdir.toString() +
            ", retrying in " + wait + "msec: " + StringUtils.stringifyException(ioe));
        try {
          Thread.sleep(wait);
        } catch (InterruptedException e) {
          throw (InterruptedIOException)new InterruptedIOException().initCause(e);
        }
      } else {
        throw ioe;
      }
    }
  }
}