@Override public synchronized void start() { setDaemon(true); LOG.info("I'm starting a bookie with journal directory {}", journalDirectory.getName()); // Start DiskChecker thread ledgerDirsManager.start(); if (indexDirsManager != ledgerDirsManager) { indexDirsManager.start(); } // start sync thread first, so during replaying journals, we could do checkpoint // which reduce the chance that we need to replay journals again if bookie restarted // again before finished journal replays. syncThread.start(); // replay journals try { readJournal(); } catch (IOException ioe) { LOG.error("Exception while replaying journals, shutting down", ioe); shutdown(ExitCode.BOOKIE_EXCEPTION); return; } catch (BookieException be) { LOG.error("Exception while replaying journals, shutting down", be); shutdown(ExitCode.BOOKIE_EXCEPTION); return; } // Do a fully flush after journal replay try { syncThread.requestFlush().get(); } catch (InterruptedException e) { LOG.warn("Interrupting the fully flush after replaying journals : ", e); Thread.currentThread().interrupt(); } catch (ExecutionException e) { LOG.error("Error on executing a fully flush after replaying journals."); shutdown(ExitCode.BOOKIE_EXCEPTION); } // start bookie thread super.start(); // After successful bookie startup, register listener for disk // error/full notifications. ledgerDirsManager.addLedgerDirsListener(getLedgerDirsListener()); if (indexDirsManager != ledgerDirsManager) { indexDirsManager.addLedgerDirsListener(getLedgerDirsListener()); } ledgerStorage.start(); // set running here. // since bookie server use running as a flag to tell bookie server whether it is alive // if setting it in bookie thread, the watcher might run before bookie thread. running = true; try { registerBookie(true).get(); } catch (Exception ie) { LOG.error("Couldn't register bookie with zookeeper, shutting down : ", ie); shutdown(ExitCode.ZK_REG_FAIL); } }