Examples with FileJournalManager org.apache.hadoop.hdfs.server.namenode.FileJournalManager used on opensource projects

Example 1 with FileJournalManager

use of org.apache.hadoop.hdfs.server.namenode.FileJournalManager in project hadoop by apache.

the class GetJournalEditServlet method doGet.

@Override
public void doGet(final HttpServletRequest request, final HttpServletResponse response) throws ServletException, IOException {
    FileInputStream editFileIn = null;
    try {
        final ServletContext context = getServletContext();
        final Configuration conf = (Configuration) getServletContext().getAttribute(JspHelper.CURRENT_CONF);
        final String journalId = request.getParameter(JOURNAL_ID_PARAM);
        QuorumJournalManager.checkJournalId(journalId);
        final JNStorage storage = JournalNodeHttpServer.getJournalFromContext(context, journalId).getStorage();
        // Check security
        if (!checkRequestorOrSendError(conf, request, response)) {
            return;
        }
        // Check that the namespace info is correct
        if (!checkStorageInfoOrSendError(storage, request, response)) {
            return;
        }
        long segmentTxId = ServletUtil.parseLongParam(request, SEGMENT_TXID_PARAM);
        FileJournalManager fjm = storage.getJournalManager();
        File editFile;
        synchronized (fjm) {
            // Synchronize on the FJM so that the file doesn't get finalized
            // out from underneath us while we're in the process of opening
            // it up.
            EditLogFile elf = fjm.getLogFile(segmentTxId);
            if (elf == null) {
                response.sendError(HttpServletResponse.SC_NOT_FOUND, "No edit log found starting at txid " + segmentTxId);
                return;
            }
            editFile = elf.getFile();
            ImageServlet.setVerificationHeadersForGet(response, editFile);
            ImageServlet.setFileNameHeaders(response, editFile);
            editFileIn = new FileInputStream(editFile);
        }
        DataTransferThrottler throttler = ImageServlet.getThrottler(conf);
        // send edits
        TransferFsImage.copyFileToStream(response.getOutputStream(), editFile, editFileIn, throttler);
    } catch (Throwable t) {
        String errMsg = "getedit failed. " + StringUtils.stringifyException(t);
        response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, errMsg);
        throw new IOException(errMsg);
    } finally {
        IOUtils.closeStream(editFileIn);
    }
}