void enterSafeMode ( ) throws IOException { writeLock ( ) ; try { // Ensure that any concurrent operations have been fully synced // before entering safe mode. This ensures that the FSImage // is entirely stable on disk as soon as we're in safe mode. getEditLog ( ) . logSyncAll ( ) ; if ( ! isInSafeMode ( ) ) { safeMode = SafeModeUtil . getInstance ( this ) ; safeMode . setManual ( ) ; return ; } safeMode . setManual ( ) ; getEditLog ( ) . logSyncAll ( ) ; NameNode . stateChangeLog . info ( "STATE* Safe mode is ON. " + safeMode . getTurnOffTip ( ) ) ; } finally { writeUnlock ( ) ; } }
Enter safe mode manually .