Examples of ReliableLog

com.sun.jini.reliableLog.ReliableLog
This class is a simple implementation of a reliable Log. The client of a ReliableLog must provide a set of callbacks (via a LogHandler) that enables a ReliableLog to read and write snapshots (checkpoints) and log records. This implementation ensures that the data stored (via a ReliableLog) is recoverable after a system crash. The implementation is unsynchronized; the client must synchronize externally.
The secondary storage strategy is to record values in files using a representation of the caller's choosing. Two sorts of files are kept: snapshots and logs. At any instant, one snapshot is current. The log consists of a sequence of updates that have occurred since the current snapshot was taken. The current stable state is the value of the snapshot, as modified by the sequence of updates in the log. From time to time, the client of a ReliableLog instructs the package to make a new snapshot and clear the log. A ReliableLog arranges disk writes such that updates are stable (as long as the changes are force-written to disk) and atomic: no update is lost, and each update either is recorded completely in the log or not at all. Making a new snapshot is also atomic.
Normal use for maintaining the recoverable store is as follows: The client maintains the relevant data structure in virtual memory. As updates happen to the structure, the client informs the ReliableLog (call it "log") by calling log.update. Periodically, the client calls log.snapshot to provide the current complete contents of the data. On restart, the client calls log.recover to obtain the latest snapshot and the following sequences of updates; the client applies the updates to the snapshot to obtain the state that existed before the crash.
@author Sun Microsystems, Inc. @see LogHandler
sun.rmi.log.ReliableLog
This class is a simple implementation of a reliable Log. The client of a ReliableLog must provide a set of callbacks (via a LogHandler) that enables a ReliableLog to read and write checkpoints and log records. This implementation ensures that the current value of the data stored (via a ReliableLog) is recoverable after a system crash.
The secondary storage strategy is to record values in files using a representation of the caller's choosing. Two sorts of files are kept: snapshots and logs. At any instant, one snapshot is current. The log consists of a sequence of updates that have occurred since the current snapshot was taken. The current stable state is the value of the snapshot, as modified by the sequence of updates in the log. From time to time, the client of a ReliableLog instructs the package to make a new snapshot and clear the log. A ReliableLog arranges disk writes such that updates are stable (as long as the changes are force-written to disk) and atomic : no update is lost, and each update either is recorded completely in the log or not at all. Making a new snapshot is also atomic.
Normal use for maintaining the recoverable store is as follows: The client maintains the relevant data structure in virtual memory. As updates happen to the structure, the client informs the ReliableLog (all it "log") by calling log.update. Periodically, the client calls log.snapshot to provide the current value of the data structure. On restart, the client calls log.recover to obtain the latest snapshot and the following sequences of updates; the client applies the updates to the snapshot to obtain the state that existed before the crash.
The current logfile format is:
1. a format version number (two 4-octet integers, major and minor), followed by
2. a sequence of log records. Each log record contains, in order,
  1. a 4-octet integer representing the length of the following log data,
  2. the log data (variable length).
@see LogHandler @author Ann Wollrath

Examples of com.sun.jini.reliableLog.ReliableLog

            persistDir = (String)Config.getNonNullEntry(config,
                                                        COMPONENT_NAME,
                                                        "persistenceDirectory",
                                                        String.class);
            /* Recover the state that was persisted on prior runs (if any) */
            log = new ReliableLog(persistDir, new LocalLogHandler());
            inRecovery = true;
            log.recover();
            inRecovery = false;
        }//endif(persistent)

View Full Code Here

Examples of com.sun.jini.reliableLog.ReliableLog

      }  


      logToSnapshotThreshold = Config.getIntEntry(config,
                MERCURY, "logToSnapshotThreshold", 50, 0, Integer.MAX_VALUE);
      
            log = new ReliableLog(persistenceDirectory, new LocalLogHandler());


      if (initLogger.isLoggable(Level.FINEST)) {
                initLogger.log(Level.FINEST, "Recovering persistent state");
      }
            inRecovery = true;

View Full Code Here

Examples of com.sun.jini.reliableLog.ReliableLog

    ProxyPreparer.class, recoveredLocatorPreparer);
      persistenceSnapshotWeight = Config.getFloatEntry(
    config, COMPONENT, "persistenceSnapshotWeight",
    persistenceSnapshotWeight, 0F, Float.MAX_VALUE);


      log = new ReliableLog(persistenceDirectory, new LocalLogHandler());
      if (logger.isLoggable(Level.CONFIG)) {
    logger.log(Level.CONFIG, "using persistence directory {0}",
         new Object[]{ persistenceDirectory });
      }
      inRecovery = true;

View Full Code Here

Examples of com.sun.jini.reliableLog.ReliableLog

        super(); 
  if (operationsLogger.isLoggable(Level.FINER)) {
            operationsLogger.entering(JoinStateManager.class.getName(), 
          "JoinStateManager", logPath);
  }
  this.log = (logPath==null) ? null : new ReliableLog(logPath, this);
  if (operationsLogger.isLoggable(Level.FINER)) {
            operationsLogger.exiting(JoinStateManager.class.getName(), 
          "JoinStateManager");
  }
    }

View Full Code Here

Examples of com.sun.jini.reliableLog.ReliableLog

        } else {
      throw e;
        }
    }
    ActLogHandler handler = new ActLogHandler();
    ReliableLog log = new ReliableLog(logName, handler);
    log.recover();
    Activation state = handler.getState();
    if (state == null) {
        log.snapshot();
        state = handler.getState();
    }
    state.init(log, login, config, configOptions, starter);
    if (starter == null) {
        // prevent exit

View Full Code Here

Examples of com.sun.jini.reliableLog.ReliableLog

      }  


      logToSnapshotThreshold = Config.getIntEntry(config,
                MERCURY, "logToSnapshotThreshold", 50, 0, Integer.MAX_VALUE);
      
            log = new ReliableLog(persistenceDirectory, new LocalLogHandler());


      if (initLogger.isLoggable(Level.FINEST)) {
                initLogger.log(Level.FINEST, "Recovering persistent state");
      }
            inRecovery = true;

View Full Code Here

Examples of com.sun.jini.reliableLog.ReliableLog

    ProxyPreparer.class, recoveredLocatorPreparer);
      persistenceSnapshotWeight = Config.getFloatEntry(
    config, COMPONENT, "persistenceSnapshotWeight",
    persistenceSnapshotWeight, 0F, Float.MAX_VALUE);


      log = new ReliableLog(persistenceDirectory, new LocalLogHandler());
      if (logger.isLoggable(Level.CONFIG)) {
    logger.log(Level.CONFIG, "using persistence directory {0}",
         new Object[]{ persistenceDirectory });
      }
      inRecovery = true;

View Full Code Here

Examples of com.sun.jini.reliableLog.ReliableLog

      }  


      logToSnapshotThreshold = Config.getIntEntry(config,
                MERCURY, "logToSnapshotThreshold", 50, 0, Integer.MAX_VALUE);
      
            log = new ReliableLog(persistenceDirectory, new LocalLogHandler());


      if (initLogger.isLoggable(Level.FINEST)) {
                initLogger.log(Level.FINEST, "Recovering persistent state");
      }
            inRecovery = true;

View Full Code Here

Examples of com.sun.jini.reliableLog.ReliableLog

        super(); 
  if (operationsLogger.isLoggable(Level.FINER)) {
            operationsLogger.entering(JoinStateManager.class.getName(), 
          "JoinStateManager", logPath);
  }
  this.log = (logPath==null) ? null : new ReliableLog(logPath, this);
  if (operationsLogger.isLoggable(Level.FINER)) {
            operationsLogger.exiting(JoinStateManager.class.getName(), 
          "JoinStateManager");
  }
    }

View Full Code Here

Examples of com.sun.jini.reliableLog.ReliableLog

  if (logDir == null) {
      storeLocation = null;
  } else {
      storeLocation = new File(logDir);
      try {
    log = new ReliableLog(
        storeLocation.getCanonicalPath(), logHandler);
      } catch (IOException e) {
    throw new CorruptedStoreException(
        "Failure creating reliable log", e);
      }

View Full Code Here

0 1 2

TOP

All source code are property of their respective owners. Java is a trademark of Sun Microsystems, Inc and owned by ORACLE Inc. Contact coftware#gmail.com.