Examples with DFSInotifyEventInputStream org.apache.hadoop.hdfs.DFSInotifyEventInputStream used on opensource projects

Example 1 with DFSInotifyEventInputStream

use of org.apache.hadoop.hdfs.DFSInotifyEventInputStream in project hadoop by apache.

the class TestEditLog method testReadActivelyUpdatedLog.

/**
   *
   * @throws Exception
   */
@Test
public void testReadActivelyUpdatedLog() throws Exception {
    final TestAppender appender = new TestAppender();
    LogManager.getRootLogger().addAppender(appender);
    Configuration conf = new HdfsConfiguration();
    conf.setBoolean(DFSConfigKeys.DFS_NAMENODE_ACLS_ENABLED_KEY, true);
    // Set single handler thread, so all transactions hit same thread-local ops.
    conf.setInt(DFSConfigKeys.DFS_NAMENODE_HANDLER_COUNT_KEY, 1);
    MiniDFSCluster cluster = null;
    try {
        cluster = new MiniDFSCluster.Builder(conf).numDataNodes(1).build();
        cluster.waitActive();
        FSImage fsimage = cluster.getNamesystem().getFSImage();
        StorageDirectory sd = fsimage.getStorage().getStorageDir(0);
        final DistributedFileSystem fileSys = cluster.getFileSystem();
        DFSInotifyEventInputStream events = fileSys.getInotifyEventStream();
        fileSys.mkdirs(new Path("/test"));
        fileSys.mkdirs(new Path("/test/dir1"));
        fileSys.delete(new Path("/test/dir1"), true);
        fsimage.getEditLog().logSync();
        fileSys.mkdirs(new Path("/test/dir2"));
        final File inProgressEdit = NNStorage.getInProgressEditsFile(sd, 1);
        assertTrue(inProgressEdit.exists());
        EditLogFileInputStream elis = new EditLogFileInputStream(inProgressEdit);
        FSEditLogOp op;
        long pos = 0;
        while (true) {
            op = elis.readOp();
            if (op != null && op.opCode != FSEditLogOpCodes.OP_INVALID) {
                pos = elis.getPosition();
            } else {
                break;
            }
        }
        elis.close();
        assertTrue(pos > 0);
        RandomAccessFile rwf = new RandomAccessFile(inProgressEdit, "rw");
        rwf.seek(pos);
        assertEquals(rwf.readByte(), (byte) -1);
        rwf.seek(pos + 1);
        rwf.writeByte(2);
        rwf.close();
        events.poll();
        String pattern = "Caught exception after reading (.*) ops";
        Pattern r = Pattern.compile(pattern);
        final List<LoggingEvent> log = appender.getLog();
        for (LoggingEvent event : log) {
            Matcher m = r.matcher(event.getRenderedMessage());
            if (m.find()) {
                fail("Should not try to read past latest syned edit log op");
            }
        }
    } finally {
        if (cluster != null) {
            cluster.shutdown();
        }
        LogManager.getRootLogger().removeAppender(appender);
    }
}