Class LogToFile

java.lang.Object
org.apache.derby.impl.store.raw.log.LogToFile
All Implemented Interfaces:
PrivilegedExceptionAction<Object>, Serviceable, ModuleControl, ModuleSupportable, Corruptable, LogFactory
public final class LogToFile extends Object implements LogFactory, ModuleControl, ModuleSupportable, Serviceable, PrivilegedExceptionAction<Object>
This is an implementation of the log using a non-circular file system file. No support for incremental log backup or media recovery. Only crash recovery is supported.

The 'log' is a stream of log records. The 'log' is implemented as a series of numbered log files. These numbered log files are logically continuous so a transaction can have log records that span multiple log files. A single log record cannot span more then one log file. The log file number is monotonically increasing.

The log belongs to a log factory of a RawStore. In the current implementation, each RawStore only has one log factory, so each RawStore only has one log (which composed of multiple log files). At any given time, a log factory only writes new log records to one log file, this log file is called the 'current log file'.

A log file is named loglogNumber.dat

Everytime a checkpoint is taken, a new log file is created and all subsequent log records will go to the new log file. After a checkpoint is taken, old and useless log files will be deleted.

RawStore exposes a checkpoint method which clients can call, or a checkpoint is taken automatically by the RawStore when

  1. the log file grows beyond a certain size (configurable, default 100K bytes)
  2. RawStore is shutdown and a checkpoint hasn't been done "for a while"
  3. RawStore is recovered and a checkpoint hasn't been done "for a while"

This LogFactory is responsible for the formats of 2 kinds of file: the log file and the log control file. And it is responsible for the format of the log record wrapper. 


Format of log control file

  • Field Details

    • INT_LENGTH

      private static final long INT_LENGTH
      See Also:

    • fid

      private static int fid

    • LOG_FILE_HEADER_SIZE

      public static final int LOG_FILE_HEADER_SIZE
      See Also:

    • LOG_FILE_HEADER_PREVIOUS_LOG_INSTANT_OFFSET

      protected static final int LOG_FILE_HEADER_PREVIOUS_LOG_INSTANT_OFFSET
      See Also:

    • LOG_RECORD_OVERHEAD

      public static final int LOG_RECORD_OVERHEAD
      See Also:

    • DBG_FLAG

      public static final String DBG_FLAG

    • DUMP_LOG_ONLY

      public static final String DUMP_LOG_ONLY

    • DUMP_LOG_FROM_LOG_FILE

      public static final String DUMP_LOG_FROM_LOG_FILE

    • LOG_SYNC_STATISTICS

      protected static final String LOG_SYNC_STATISTICS
      See Also:

    • OBSOLETE_LOG_VERSION_NUMBER

      private static final int OBSOLETE_LOG_VERSION_NUMBER
      See Also:

    • DEFAULT_LOG_SWITCH_INTERVAL

      private static final int DEFAULT_LOG_SWITCH_INTERVAL
      See Also:

    • LOG_SWITCH_INTERVAL_MIN

      private static final int LOG_SWITCH_INTERVAL_MIN
      See Also:

    • LOG_SWITCH_INTERVAL_MAX

      private static final int LOG_SWITCH_INTERVAL_MAX
      See Also:

    • CHECKPOINT_INTERVAL_MIN

      private static final int CHECKPOINT_INTERVAL_MIN
      See Also:

    • CHECKPOINT_INTERVAL_MAX

      private static final int CHECKPOINT_INTERVAL_MAX
      See Also:

    • DEFAULT_CHECKPOINT_INTERVAL

      private static final int DEFAULT_CHECKPOINT_INTERVAL
      See Also:

    • DEFAULT_LOG_BUFFER_SIZE

      private static final int DEFAULT_LOG_BUFFER_SIZE
      See Also:

    • LOG_BUFFER_SIZE_MIN

      private static final int LOG_BUFFER_SIZE_MIN
      See Also:

    • LOG_BUFFER_SIZE_MAX

      private static final int LOG_BUFFER_SIZE_MAX
      See Also:

    • logBufferSize

      private int logBufferSize

    • IS_BETA_FLAG

      private static final byte IS_BETA_FLAG
      See Also:

    • IS_DURABILITY_TESTMODE_NO_SYNC_FLAG

      private static final byte IS_DURABILITY_TESTMODE_NO_SYNC_FLAG
      When the derby.system.durability property is set to 'test', the store system will not force sync calls in the following cases - for the log file at each commit - for the log file before data page is forced to disk - for page allocation when file is grown - for data writes during checkpoint This means it is possible that the recovery system may not work properly, committed transactions may be lost, and/or database may not be in a consistent state. In order that we recognize this case that the database was previously at any time booted in this mode, this value is written out into the log control file. This will help prevent us from wasting time to resolve issues in such cases.
      See Also:

    • wasDBInDurabilityTestModeNoSync

      private static boolean wasDBInDurabilityTestModeNoSync
      keeps track of if the database was booted previously at any time with derby.system.durability=test

    • DEFAULT_LOG_ARCHIVE_DIRECTORY

      private static final String DEFAULT_LOG_ARCHIVE_DIRECTORY
      See Also:

    • logSwitchInterval

      private int logSwitchInterval

    • checkpointInterval

      private int checkpointInterval

    • dataDirectory

      String dataDirectory

    • logStorageFactory

      private WritableStorageFactory logStorageFactory

    • logBeingFlushed

      private boolean logBeingFlushed

    • logOut

      protected LogAccessFile logOut

    • firstLog

      private StorageRandomAccessFile firstLog

    • endPosition

      protected long endPosition

    • lastFlush

      long lastFlush

    • logFileNumber

      long logFileNumber

    • bootTimeLogFileNumber

      long bootTimeLogFileNumber

    • firstLogFileNumber

      long firstLogFileNumber

    • maxLogFileNumber

      private long maxLogFileNumber

    • currentCheckpoint

      private CheckpointOperation currentCheckpoint

    • checkpointInstant

      long checkpointInstant

    • checkpointDaemon

      private DaemonService checkpointDaemon

    • myClientNumber

      private int myClientNumber

    • checkpointDaemonCalled

      private volatile boolean checkpointDaemonCalled

    • logWrittenFromLastCheckPoint

      private long logWrittenFromLastCheckPoint

    • rawStoreFactory

      private RawStoreFactory rawStoreFactory

    • dataFactory

      protected DataFactory dataFactory

    • ReadOnlyDB

      protected boolean ReadOnlyDB

    • masterFactory

      private MasterFactory masterFactory

    • inReplicationMasterMode

      private boolean inReplicationMasterMode

    • inReplicationSlaveMode

      private boolean inReplicationSlaveMode

    • replicationSlaveException

      private volatile StandardException replicationSlaveException
      If this exception is set while in replication slave mode, the exception will be thrown by the thread doing recovery will. Effectively, this will shut down the database.

    • inReplicationSlavePreMode

      private boolean inReplicationSlavePreMode
      True if the database has been booted in replication slave pre mode, effectively turning off writes to the log file.
      See Also:

    • slaveRecoveryMonitor

      private Object slaveRecoveryMonitor

    • allowedToReadFileNumber

      private long allowedToReadFileNumber

    • keepAllLogs

      private boolean keepAllLogs

    • databaseEncrypted

      private boolean databaseEncrypted

    • recoveryNeeded

      private boolean recoveryNeeded

    • inCheckpoint

      private boolean inCheckpoint

    • inRedo

      private boolean inRedo

    • inLogSwitch

      private boolean inLogSwitch

    • stopped

      private boolean stopped

    • logDevice

      String logDevice

    • logNotSynced

      private boolean logNotSynced

    • logArchived

      private volatile boolean logArchived

    • logSwitchRequired

      private boolean logSwitchRequired

    • test_logWritten

      int test_logWritten
      DEBUG test only

    • test_numRecordToFillLog

      int test_numRecordToFillLog

    • mon_flushCalls

      private int mon_flushCalls

    • mon_syncCalls

      private int mon_syncCalls

    • mon_numLogFlushWaits

      private int mon_numLogFlushWaits

    • mon_LogSyncStatistics

      private boolean mon_LogSyncStatistics

    • mon_numBytesToLog

      private int mon_numBytesToLog

    • corrupt

      protected volatile StandardException corrupt
      If not null then something is corrupt in the raw store and this represents the original error.

    • isFrozen

      private boolean isFrozen
      If frozen, don't allow anything on disk to change.

    • jbmsVersion

      ProductVersionHolder jbmsVersion
      Product Version information. Invarient after boot.

    • onDiskMajorVersion

      private int onDiskMajorVersion
      On disk database version information. When running in soft upgrade this version may be different to jbmsVersion.

    • onDiskMinorVersion

      private int onDiskMinorVersion

    • onDiskBeta

      private boolean onDiskBeta

    • checksum

      private CRC32 checksum

    • isWriteSynced

      private boolean isWriteSynced
      Note: Why logging system support file sync and write sync ? Note : The reason to support file and write sync of logs is there was no support to do write sync until jdk1.4 and then there was write sync jvm bug in jdk1.4.1, only in jdk1.4.2 write sync(rws and rwd modes) mechanism can be used correctly. Default in JVMS >= jdk1.4.2 is write sync(see the boot method for jvm checks). Write sync mechanism support is added for performance reasons. On commits, logging system has to make sure the log for committed transaction is on disk. With out write sync , log is written to the disk and then fsync() is used on commits to make log is written to the disk for sure. On most of the OS , fsync() calls are expensive. On heavy commit oriented systems, file sync make the system run slow. This problem is solved by using write sync on preallocated log file. write sync is much faster than doing write and file sync to a file. File should be preallocated for write syncs to perform better than the file sync method. Whenever a new log file is created, logSwitchInterval size is preallocated by writing zeros after file after the header.

    • jvmSyncErrorChecked

      private boolean jvmSyncErrorChecked
      Status for whether the check on the sync error on some JVMs has been done or not. See the checkJvmSyncError method for details.

    • logFileToBackup

      private volatile long logFileToBackup

    • backupInProgress

      private volatile boolean backupInProgress

    • TEST_LOG_SWITCH_LOG

      public static final String TEST_LOG_SWITCH_LOG
      Set to true if we want the checkpoint to only switch the log but not actually do the checkpoint

    • TEST_LOG_INCOMPLETE_LOG_WRITE

      public static final String TEST_LOG_INCOMPLETE_LOG_WRITE
      Set to true if we want the upcoming log record to be only partially written. The database is corrupted if not immediately shutdown. Set TEST_LOG_PARTIAL_LOG_WRITE_NUM_BYTES to the number of bytes to write out, default is 1 byte.

    • TEST_LOG_PARTIAL_LOG_WRITE_NUM_BYTES

      public static final String TEST_LOG_PARTIAL_LOG_WRITE_NUM_BYTES
      Set to the number of bytes we want the next log record to actually write out, only used when TEST_LOG_INCOMPLETE_LOG_WRITE is on. Default is 1 byte.

    • TEST_LOG_FULL

      public static final String TEST_LOG_FULL
      Set to true if we want to simulate a log full condition

    • TEST_SWITCH_LOG_FAIL1

      public static final String TEST_SWITCH_LOG_FAIL1
      Set to true if we want to simulate a log full condition while switching log

    • TEST_SWITCH_LOG_FAIL2

      public static final String TEST_SWITCH_LOG_FAIL2

    • TEST_RECORD_TO_FILL_LOG

      public static final String TEST_RECORD_TO_FILL_LOG
      Set to the number of log record we want to write before the log is simulated to be full.

    • TEST_MAX_LOGFILE_NUMBER

      public static final String TEST_MAX_LOGFILE_NUMBER
      Set to true if we want to simulate max possible log file number is being used.

    • action

      private int action

    • activeFile

      private StorageFile activeFile

    • toFile

      private File toFile

    • activePerms

      private String activePerms

  • Constructor Details

    • LogToFile

      public LogToFile()
      MT- not needed for constructor

  • Method Details

    • getTypeFormatId

      public int getTypeFormatId()
      Return my format identifier.

    • markCorrupt

      public StandardException markCorrupt(StandardException originalError)
      Once the log factory is marked as corrupt then the raw store will shut down.
      Specified by:
      markCorrupt in interface Corruptable
      Returns:
      Must always return its parameter.

    • checkCorrupt

      private void checkCorrupt() throws StandardException
      Throws:
      StandardException

    • getLogger

      public Logger getLogger()
      MT- not needed
      Specified by:
      getLogger in interface LogFactory

    • setRawStoreFactory

      public void setRawStoreFactory(RawStoreFactory rsf)
      Make log factory aware of which raw store factory it belongs to
      Specified by:
      setRawStoreFactory in interface LogFactory

    • recover

      public void recover(DataFactory df, TransactionFactory tf) throws StandardException
      Recover the rawStore to a consistent state using the log.

      In this implementation, the log is a stream of log records stored in one or more flat files. Recovery is done in 2 passes: redo and undo.
      Redo pass
      In the redo pass, reconstruct the state of the rawstore by repeating exactly what happened before as recorded in the log.
      Undo pass
      In the undo pass, all incomplete transactions are rolled back in the order from the most recently started to the oldest.

      MT - synchronization provided by caller - RawStore boot. This method is guaranteed to be the only method being called and can assume single thread access on all fields.

      Specified by:
      recover in interface LogFactory
      Parameters:
      df - - the data factory
      tf - - the transaction factory
      Throws:
      StandardException - Standard Derby error policy
      See Also:

    • checkpoint

      public boolean checkpoint(RawStoreFactory rsf, DataFactory df, TransactionFactory tf, boolean wait) throws StandardException
      Checkpoint the rawStore.

      MT- Only one checkpoint is to be taking place at any given time.

      The steps of a checkpoint are

      1. switch to a new log file if possible 
                freeze the log (for the transition to a new log file)
                flush current log file
                create and flush the new log file (with file number 1 higher
              than the previous log file). The new log file becomes the
              current log file.
        unfreeze the log
      2. start checkpoint transaction
      3. gather interesting information about the rawStore: the current log instant (redoLWM) the earliest active transaction begin tran log record instant (undoLWM), all the truncation LWM set by clients of raw store (replication)
      4. clean the buffer cache
      5. log the next checkpoint log record, which contains (repPoint, undoLWM, redoLWM) and commit checkpoint transaction.
      6. synchronously write the control file containing the next checkpoint log record log instant
      7. the new checkpoint becomes the current checkpoint. Somewhere near the beginning of each log file should be a checkpoint log record (not guarenteed to be there)
      8. see if the log can be truncated

        The earliest useful log record is determined by the repPoint and the undoLWM, whichever is earlier.

        Every log file whose log file number is smaller than the earliest useful log record's log file number can be deleted. 

                Transactions can be at the following states w/r to a checkpoint -
        consider the log as a continous stream and not as series of log 
          files for the sake of clarity.  
        |(BT)-------(ET)| marks the begin and end of a transaction.
        .                          checkpoint started
        .       |__undoLWM          |
        .       V                   |___redoLWM
        .                           |___TruncationLWM
        .                           |
        .                           V
        1 |-----------------|
        2       |--------------------------------|
        3           |-------|
        4               |--------------------------------------(end of log)
        5                                       |-^-|
        .                                   Checkpoint Log Record
        ---A--->|<-------B--------->|<-------------C-----------

        There are only 3 periods of interest :
        A) before undoLWM, B) between undo and redo LWM, C) after redoLWM.

        Transaction 1 started in A and terminates in B.
        During redo, we should only see log records and endXact from this transaction in the first phase (between undoLWM and redoLWM). No beginXact log record for this transaction will be seen.

        Transaction 2 started in B (right on the undoLWM) and terminated in C.
        Any transaction that terminates in C must have a beginXact at or after undoLWM. In other words, no transaction can span A, B and C. During redo, we will see beginXact, other log records and endXact for this transaction.

        Transaction 3 started in B and ended in B.
        During redo, we will see beginXact, other log records and endXact for this transaction.

        Transaction 4 begins in B and never ends.
        During redo, we will see beginXact, other log records. In undo, this loser transaction will be rolled back.

        Transaction 5 is the transaction taking the checkpoint.
        The checkpoint action started way back in time but the checkpoint log record is only written after the buffer cache has been flushed.

        Note that if any time elapse between taking the undoLWM and the redoLWM, then it will create a 4th period of interest.

      Specified by:
      checkpoint in interface LogFactory
      Parameters:
      rsf - The RawStoreFactory to use to do the checkpoint.
      df - The DataFactory to use to do the checkpoint.
      tf - The TransactionFactory to use to do the checkpoint.
      wait - If an existing checkpoint is in progress, then if wait=true then this routine will wait for the checkpoint to complete and the do another checkpoint and wait for it to finish before returning.
      Returns:
      true if checkpoint is successful, Will return false if wait is false and the routine finds another thread executing a checkpoint.
      Throws:
      StandardException - - encounter exception while doing checkpoint.

    • checkpointWithTran

      private boolean checkpointWithTran(RawTransaction cptran, RawStoreFactory rsf, DataFactory df, TransactionFactory tf, boolean wait) throws StandardException
      checkpoint with pre-start transaction
      Parameters:
      rsf - The RawStoreFactory to use to do the checkpoint.
      df - The DataFactory to use to do the checkpoint.
      tf - The TransactionFactory to use to do the checkpoint.
      wait - If an existing checkpoint is in progress, then if wait=true then this routine will wait for the checkpoint to complete and the do another checkpoint and wait for it to finish before returning.
      Throws:
      StandardException - Derby Standard Error Policy

    • flush

      public void flush(LogInstant where) throws StandardException
      Flush all unwritten log record up to the log instance indicated to disk and sync. Also check to see if database is frozen or corrupt.

      MT - not needed, wrapper method

      Specified by:
      flush in interface LogFactory
      Parameters:
      where - flush log up to here
      Throws:
      StandardException - Standard Derby error policy

    • flushAll

      public void flushAll() throws StandardException
      Flush all unwritten log record to disk and sync. Also check to see if database is frozen or corrupt.

      MT - not needed, wrapper method

      Throws:
      StandardException - Standard Derby error policy

    • verifyLogFormat

      private boolean verifyLogFormat(StorageFile logFileName, long number) throws StandardException
      Verify that we the log file is of the right format and of the right version and log file number.

      MT - not needed, no global variables used

      Parameters:
      logFileName - the name of the log file
      number - the log file number
      Returns:
      true if the log file is of the current version and of the correct format
      Throws:
      StandardException - Standard Derby error policy

    • verifyLogFormat

      private boolean verifyLogFormat(StorageRandomAccessFile log, long number) throws StandardException
      Verify that we the log file is of the right format and of the right version and log file number. The log file position is set to the beginning.

      MT - MT-unsafe, caller must synchronize

      Parameters:
      log - the log file
      number - the log file number
      Returns:
      true if the log file is of the current version and of the correct format
      Throws:
      StandardException - Standard Derby error policy

    • initLogFile

      private boolean initLogFile(StorageRandomAccessFile newlog, long number, long prevLogRecordEndInstant) throws IOException, StandardException
      Initialize the log to the correct format with the given version and log file number. The new log file must be empty. After initializing, the file is synchronously written to disk.

      MT - synchornization provided by caller

      Parameters:
      newlog - the new log file to be initialized
      number - the log file number
      prevLogRecordEndInstant - the end position of the previous log record
      Returns:
      true if the log file is empty, else false.
      Throws:
      IOException - if new log file cannot be accessed or initialized
      StandardException

    • switchLogFile

      public void switchLogFile() throws StandardException
      Switch to the next log file if possible.

      MT - log factory is single threaded thru a log file switch, the log is frozen for the duration of the switch

      Throws:
      StandardException

    • flushBuffer

      private void flushBuffer(long fileNumber, long wherePosition) throws IOException, StandardException
      Flush all unwritten log record up to the log instance indicated to disk without syncing.

      MT - not needed, wrapper method

      Parameters:
      wherePosition - flush log up to here
      Throws:
      IOException - Failed to flush to the log
      StandardException

    • truncateLog

      private void truncateLog(CheckpointOperation checkpoint)
      Get rid of old and unnecessary log files

      MT- only one truncate log is allowed to be taking place at any given time. Synchronized on this.

    • truncateLog

      private void truncateLog(long firstLogNeeded)
      Get rid of old and unnecessary log files
      Parameters:
      firstLogNeeded - The log file number of the oldest log file needed for recovery.

    • getFirstLogNeeded

      private long getFirstLogNeeded(CheckpointOperation checkpoint)
      Return the "oldest" log file still needed by recovery.

      Returns the log file that contains the undoLWM, ie. the oldest log record of all uncommitted transactions in the given checkpoint. If no checkpoint is given then returns -1, indicating all log records may be necessary.

    • writeControlFile

      boolean writeControlFile(StorageFile logControlFileName, long value) throws IOException, StandardException
      Carefully write out this value to the control file. We do safe write of this data by writing the data into two files every time we write the control data. we write checksum at the end of the file, so if by chance system crashes while writing into the file, using the checksum we find that the control file is hosed then we use the mirror file, which will have the control data written at last check point. see comment at beginning of file for log control file format.

      MT- synchronized by caller

      Throws:
      IOException
      StandardException

    • readControlFile

      private long readControlFile(StorageFile logControlFileName, Properties startParams) throws IOException, StandardException
      Throws:
      IOException
      StandardException

    • createLogDirectory

      private void createLogDirectory() throws StandardException
      Create the directory where transaction log should go.
      Throws:
      StandardException - Standard Error Policy

    • createDataWarningFile

      public void createDataWarningFile() throws StandardException
      Create readme file in log directory warning users against touching any files in the directory
      Specified by:
      createDataWarningFile in interface LogFactory
      Throws:
      StandardException

    • getLogDirectory

      public StorageFile getLogDirectory() throws StandardException
      Description copied from interface: LogFactory
      Return the location of the log directory.
      Specified by:
      getLogDirectory in interface LogFactory
      Throws:
      StandardException - Standard Derby Error Policy

    • getCanonicalLogPath

      public String getCanonicalLogPath()
      Description copied from interface: LogFactory
      Return the canonical directory of the PARENT of the log directory. The log directory live in the "log" subdirectory of this path. If the log is at the default location (underneath the database directory), this returns null. Should only be called after the log factory is booted.
      Specified by:
      getCanonicalLogPath in interface LogFactory

    • getControlFileName

      private StorageFile getControlFileName() throws StandardException
      Return the control file name

      MT- read only

      Throws:
      StandardException

    • getMirrorControlFileName

      private StorageFile getMirrorControlFileName() throws StandardException
      Return the mirror control file name

      MT- read only

      Throws:
      StandardException

    • getLogFileName

      private StorageFile getLogFileName(long filenumber) throws StandardException
      Given a log file number, return its file name

      MT- read only

      Throws:
      StandardException

    • findCheckpoint

      private CheckpointOperation findCheckpoint(long checkpointInstant, FileLogger logger) throws IOException, StandardException, ClassNotFoundException
      Throws:
      IOException
      StandardException
      ClassNotFoundException

    • openBackwardsScan

      protected LogScan openBackwardsScan(long startAt, LogInstant stopAt) throws IOException, StandardException
      Scan backward from start position.

      MT- read only

      Throws:
      IOException - cannot access the log
      StandardException - Standard Derby error policy

    • openBackwardsScan

      protected LogScan openBackwardsScan(LogInstant stopAt) throws IOException, StandardException
      Scan backward from end of log.

      MT- read only

      Throws:
      IOException - cannot access the log
      StandardException - Standard Derby error policy

    • openFlushedScan

      public ScanHandle openFlushedScan(DatabaseInstant start, int groupsIWant) throws StandardException
      Description copied from interface: LogFactory
      Get a ScanHandle to scan flushed records from the log.

      MT- read only

      Specified by:
      openFlushedScan in interface LogFactory
      Parameters:
      start - - the LogInstant where we start our scan. null means start at the beginning of the log. This function raises an error if startAt is a LogInstant which is not in the log.
      groupsIWant - - log record groups the scanner wants.
      Returns:
      the LogScan.
      Throws:
      StandardException - Ooops.
      See Also:

    • openForwardsScan

      protected LogScan openForwardsScan(long startAt, LogInstant stopAt) throws IOException, StandardException
      Scan Forward from start position.

      MT- read only

      Parameters:
      startAt - - if startAt == INVALID_LOG_INSTANT, start from the beginning of the log. Otherwise, start scan from startAt.
      stopAt - - if not null, stop at this log instant (inclusive). Otherwise, stop at the end of the log
      Throws:
      IOException - cannot access the log
      StandardException - Standard Derby error policy

    • getLogFileAtBeginning

      protected StorageRandomAccessFile getLogFileAtBeginning(long filenumber) throws IOException, StandardException
      Open a log file and position the file at the beginning. Used by scan to switch to the next log file

      MT- read only

      When the database is in slave replication mode only: Assumes that only recover() will call this method after initializeReplicationSlaveRole() has been called, and until slave replication has ended. If this changes, the current implementation will fail.

      Throws:
      StandardException - Standard Derby error policy
      IOException - cannot access the log at the new position.

    • getLogFileAtPosition

      protected StorageRandomAccessFile getLogFileAtPosition(long logInstant) throws IOException, StandardException
      Get a read-only handle to the log file positioned at the stated position

      MT- read only

      Returns:
      null if file does not exist or of the wrong format
      Throws:
      IOException - cannot access the log at the new position.
      StandardException - Standard Derby error policy

    • canSupport

      public boolean canSupport(Properties startParams)
      Description copied from interface: ModuleSupportable
      See if this implementation can support any attributes that are listed in properties. This call may be made on a newly created instance before the boot() method has been called, or after the boot method has been called for a running module.

      The module can check for attributes in the properties to see if it can fulfill the required behaviour. E.g. the raw store may define an attribute called RawStore.Recoverable. If a temporary raw store is required the property RawStore.recoverable=false would be added to the properties before calling bootServiceModule. If a raw store cannot support this attribute its canSupport method would return null. Also see the Monitor class's prologue to see how the identifier is used in looking up properties.
      Actually a better way maybe to have properties of the form RawStore.Attributes.mandatory=recoverable,smallfootprint and RawStore.Attributes.requested=oltp,fast

      Specified by:
      canSupport in interface ModuleSupportable
      Returns:
      true if this instance can be used, false otherwise.

    • boot

      public void boot(boolean create, Properties startParams) throws StandardException
      Boot up the log factory.

      MT- caller provide synchronization

      Specified by:
      boot in interface ModuleControl
      Throws:
      StandardException - log factory cannot start up
      See Also:

    • getLogStorageFactory

      private void getLogStorageFactory() throws StandardException
      Throws:
      StandardException

    • stop

      public void stop()
      Stop the log factory

      MT- caller provide synchronization (RESOLVE: this should be called AFTER dataFactory and transFactory are stopped)

      Specified by:
      stop in interface ModuleControl
      See Also:

    • deleteObsoleteLogfiles

      private void deleteObsoleteLogfiles()

    • serviceASAP

      public boolean serviceASAP()
      Description copied from interface: Serviceable
      If this work should be done as soon as possible, then return true. If it doesn't make any difference if it is done sooner rather than later, then return false. The difference is whether or not the daemon service will be notified to work on this when this work is enqueued or subscribed, in case the serviceable work is put together but not sent to the daemon service directly, like in post commit processing

      MT - MT safe

      Specified by:
      serviceASAP in interface Serviceable

    • serviceImmediately

      public boolean serviceImmediately()
      Description copied from interface: Serviceable
      If this work should be done immediately on the user thread then return true. If it doesn't make any difference if this work is done on a the user thread immediately or if it is performed by another thread asynchronously later, then return false.
      Specified by:
      serviceImmediately in interface Serviceable

    • getLogFactoryProperties

      public void getLogFactoryProperties(PersistentSet set) throws StandardException
      Description copied from interface: LogFactory
      Get JBMS properties relevant to the log factory
      Specified by:
      getLogFactoryProperties in interface LogFactory
      Throws:
      StandardException - Standard Derby Error Policy

    • performWork

      public int performWork(ContextManager context)
      Description copied from interface: Serviceable
      Do whatever it is that you want the daemon to do for you. There may be multiple daemon objects on different thread calling performWork at the same time. The DaemonService will always call performWork with a context manager set up. the DaemonService will clean up the context if an exception is thrown. However, it is up to performWork to manage its own transaction. If you start a transaction in performWork, you must commit or abort it at the end. You may leave the transaction open so that other serviceable may use the transaction and context without starting a new one. On the same token, there may already be an opened transaction on the context. Serviceable performWork should always check the state of the context before use. A Serviceable object should be well behaved while it is performing the daemon work, i.e., it should not take too many resources or hog the CPU for too long or deadlock with anyone else.
      Specified by:
      performWork in interface Serviceable
      Parameters:
      context - the contextManager set up by the DaemonService. There may or may not be the necessary context on it, depending on which other Serviceable object it has done work for.
      Returns:
      the return status is only significant if the Serviceable client was enqueued instead of subscribed. For subscribed client, the return status is ignored. For enqueue client, it returns DONE or REQUEUE. If a REQUEUEd is returned, it would be desirable if this should not be serviceASAP, although no harm is done if this still maintains that this should be serviced ASAP ...

    • appendLogRecord

      public long appendLogRecord(byte[] data, int offset, int length, byte[] optionalData, int optionalDataOffset, int optionalDataLength) throws StandardException
      Append length bytes of data to the log prepended by a long log instant and followed by 4 bytes of length information.

      This method is synchronized to ensure log records are added sequentially to the end of the log.

      MT- single threaded through this log factory. Log records are appended one at a time.

      Throws:
      StandardException - Log Full.

    • currentInstant

      protected long currentInstant()
      Get the current log instant - this is the log instant of the Next log record to be written out

      MT - This method is synchronized to ensure that it always points to the end of a log record, not the middle of one.

    • endPosition

      protected long endPosition()

    • getLogFileNumber

      private long getLogFileNumber()
      Return the current log file number.

      MT - this method is synchronized so that it is not in the middle of being changed by swithLogFile

    • firstLogInstant

      private long firstLogInstant()
      Get the first valid log instant - this is the beginning of the first log file

      MT- synchronized on this

    • flush

      protected void flush(long fileNumber, long wherePosition) throws StandardException
      Flush the log such that the log record written with the instant wherePosition is guaranteed to be on disk.

      MT - only one flush is allowed to be taking place at any given time (RESOLVE: right now it single thread thru the log factory while the log is frozen)

      Throws:
      StandardException - cannot sync log file

    • syncFile

      private void syncFile(StorageRandomAccessFile raf) throws StandardException
      Utility routine to call sync() on the input file descriptor.

      Throws:
      StandardException

    • openForwardsFlushedScan

      public LogScan openForwardsFlushedScan(LogInstant startAt) throws StandardException
      Open a forward scan of the transaction log.

      MT- read only

      Specified by:
      openForwardsFlushedScan in interface LogFactory
      Parameters:
      startAt - - the LogInstant where we start our scan. null means start at the beginning of the log. This function raises an error if startAt is a LogInstant which is not in the log.
      Returns:
      the LogScan.
      Throws:
      StandardException - Standard Derby exception policy

    • openForwardsScan

      public LogScan openForwardsScan(LogInstant startAt, LogInstant stopAt) throws StandardException
      Get a forwards scan
      Specified by:
      openForwardsScan in interface LogFactory
      Parameters:
      startAt - - the LogInstant where we start our scan. null means start at the beginning of the log. This function raises an error if startAt is a LogInstant which is not in the log.
      stopAt - - the LogInstant where we stop our scan. null means stop at the end of the log. This function raises an error if stopAt is a LogInstant which is not in the log.
      Returns:
      the LogScan.
      Throws:
      StandardException - Standard Derby error policy

    • databaseEncrypted

      public final boolean databaseEncrypted()

    • setDatabaseEncrypted

      public void setDatabaseEncrypted(boolean isEncrypted, boolean flushLog) throws StandardException
      Sets whether the database is encrypted, all the transaction log has to be encrypted, and flush the log if requested.

      Log needs to be flushed first if the cryptographic state of the database changes (for instance re-encryption with a new key).

      Specified by:
      setDatabaseEncrypted in interface LogFactory
      Parameters:
      isEncrypted - true if the database is encrypted, false if not
      flushLog - true if log needs to be flushed, false otherwise
      Throws:
      StandardException

    • startNewLogFile

      public void startNewLogFile() throws StandardException
      Specified by:
      startNewLogFile in interface LogFactory
      Throws:
      StandardException

    • isCheckpointInLastLogFile

      public boolean isCheckpointInLastLogFile() throws StandardException
      Specified by:
      isCheckpointInLastLogFile in interface LogFactory
      Throws:
      StandardException

    • deleteLogFileAfterCheckpointLogFile

      public void deleteLogFileAfterCheckpointLogFile() throws StandardException
      Specified by:
      deleteLogFileAfterCheckpointLogFile in interface LogFactory
      Throws:
      StandardException

    • encrypt

      public int encrypt(byte[] cleartext, int offset, int length, byte[] ciphertext, int outputOffset) throws StandardException
      Throws:
      StandardException - Standard Derby Error Policy
      See Also:

    • decrypt

      public int decrypt(byte[] ciphertext, int offset, int length, byte[] cleartext, int outputOffset) throws StandardException
      Throws:
      StandardException - Standard Derby Error Policy
      See Also:

    • getEncryptionBlockSize

      public int getEncryptionBlockSize()
      return the encryption block size used during encrypted db creation

    • getEncryptedDataLength

      public int getEncryptedDataLength(int length)
      returns the length that will make the data to be multiple of encryption block size based on the given length. Block cipher algorithms like DES and Blowfish ..etc require their input to be an exact multiple of the block size.

    • getFirstUnflushedInstant

      public LogInstant getFirstUnflushedInstant()
      Get the instant of the first record which was not flushed.

      This only works after running recovery the first time.

      MT - RESOLVE:

      Specified by:
      getFirstUnflushedInstant in interface LogFactory

    • getFirstUnflushedInstantAsLong

      public long getFirstUnflushedInstantAsLong()
      Description copied from interface: LogFactory
      Get the log instant long value of the first log record that has not been flushed. Only works after recover() has finished, or (if in slave replication mode) after calling initializeReplicationSlaveRole.
      Specified by:
      getFirstUnflushedInstantAsLong in interface LogFactory
      Returns:
      the log instant long value of the first log record that has not been flushed

    • freezePersistentStore

      public void freezePersistentStore() throws StandardException
      Backup restore - stop sending log record to the log stream
      Specified by:
      freezePersistentStore in interface LogFactory
      Throws:
      StandardException - Standard Derby error policy

    • unfreezePersistentStore

      public void unfreezePersistentStore() throws StandardException
      Backup restore - start sending log record to the log stream
      Specified by:
      unfreezePersistentStore in interface LogFactory
      Throws:
      StandardException - Standard Derby error policy

    • logArchived

      public boolean logArchived()
      Backup restore - is the log being archived to some directory? if log archive mode is enabled return true else false
      Specified by:
      logArchived in interface LogFactory
      Returns:
      true if the log is being archived.

    • checkVersion

      boolean checkVersion(int requiredMajorVersion, int requiredMinorVersion)
      Check to see if a database has been upgraded to the required level in order to use a store feature.
      Parameters:
      requiredMajorVersion - required database Engine major version
      requiredMinorVersion - required database Engine minor version
      Returns:
      True if the database has been upgraded to the required level, false otherwise.

    • checkVersion

      public boolean checkVersion(int requiredMajorVersion, int requiredMinorVersion, String feature) throws StandardException
      Check to see if a database has been upgraded to the required level in order to use a store feature.
      Specified by:
      checkVersion in interface LogFactory
      Parameters:
      requiredMajorVersion - required database Engine major version
      requiredMinorVersion - required database Engine minor version
      feature - Non-null to throw an exception, null to return the state of the version match.
      Returns:
      true if the database has been upgraded to the required level, false otherwise.
      Throws:
      StandardException - if the database is not at the require version when feature feature is not null .

    • logErrMsg

      protected void logErrMsg(String msg)
      Print error message to user about the log MT - not needed, informational only

    • logErrMsg

      protected void logErrMsg(Throwable t)
      Print error message to user about the log MT - not needed, informational only

    • logErrMsgForDurabilityTestModeNoSync

      private void logErrMsgForDurabilityTestModeNoSync()
      In case of boot errors, and if database is either booted with derby.system.durability=test or was previously at any time booted in this mode, mention in the error message that the error is probably because the derby.system.durability was set. Dont want to waste time to resolve issues in such cases

      MT - not needed, informational only

    • printErrorStack

      private void printErrorStack(Throwable t)
      print stack trace from the Throwable including its nested exceptions
      Parameters:
      t - trace starts from this error

    • logtest_appendPartialLogRecord

      private long logtest_appendPartialLogRecord(byte[] data, int offset, int length, byte[] optionalData, int optionalDataOffset, int optionalDataLength) throws StandardException
      Writes out a partial log record - takes the appendLogRecord. Need to shutdown the database before another log record gets written, or the database is not recoverable.
      Throws:
      StandardException

    • testLogFull

      protected void testLogFull() throws IOException
      Simulate a log full condition if TEST_LOG_FULL is set to true, then the property TEST_RECORD_TO_FILL_LOG indicates the number of times this function is call before an IOException simulating a log full condition is raised. If TEST_RECORD_TO_FILL_LOG is not set, it defaults to 100 log record
      Throws:
      IOException

    • getLogFileToSimulateCorruption

      public StorageRandomAccessFile getLogFileToSimulateCorruption(long filenum) throws IOException, StandardException
      Get the log file to Simulate a log corruption FOR UNIT TESTING USAGE ONLY
      Throws:
      IOException
      StandardException

    • inReplicationMasterMode

      public boolean inReplicationMasterMode()
      Used to determine if the replication master mode has been started, and the logging for unlogged operations needs to be enabled.
      Specified by:
      inReplicationMasterMode in interface LogFactory
      Returns:
      true If the master replication mode is turned on and the unlogged operations need to be logged. false If the master replication mode is turned off and the unlogged operations need not be logged.

    • enableLogArchiveMode

      public void enableLogArchiveMode() throws StandardException
      Specified by:
      enableLogArchiveMode in interface LogFactory
      Throws:
      StandardException

    • disableLogArchiveMode

      public void disableLogArchiveMode() throws StandardException
      Specified by:
      disableLogArchiveMode in interface LogFactory
      Throws:
      StandardException

    • deleteOnlineArchivedLogFiles

      public void deleteOnlineArchivedLogFiles()
      Specified by:
      deleteOnlineArchivedLogFiles in interface LogFactory

    • startLogBackup

      public void startLogBackup(File toDir) throws StandardException
      Specified by:
      startLogBackup in interface LogFactory
      Throws:
      StandardException

    • backupLogFiles

      private void backupLogFiles(File toDir, long lastLogFileToBackup) throws StandardException
      Throws:
      StandardException

    • endLogBackup

      public void endLogBackup(File toDir) throws StandardException
      Specified by:
      endLogBackup in interface LogFactory
      Throws:
      StandardException

    • abortLogBackup

      public void abortLogBackup()
      Specified by:
      abortLogBackup in interface LogFactory

    • inRFR

      public boolean inRFR()
      Specified by:
      inRFR in interface LogFactory

    • checkpointInRFR

      public void checkpointInRFR(LogInstant cinstant, long redoLWM, long undoLWM, DataFactory df) throws StandardException
      redo a checkpoint during rollforward recovery
      Specified by:
      checkpointInRFR in interface LogFactory
      Parameters:
      cinstant - The LogInstant of the checkpoint
      redoLWM - Redo Low Water Mark in the check point record
      undoLWM - Undo Low Water Mark in the checkpoint
      df - - the data factory
      Throws:
      StandardException

    • startReplicationMasterRole

      public void startReplicationMasterRole(MasterFactory masterFactory) throws StandardException
      Make this LogFactory pass log records to the MasterFactory every time a log record is appended to the log on disk, and notify the MasterFactory when a log disk flush has taken place.
      Specified by:
      startReplicationMasterRole in interface LogFactory
      Parameters:
      masterFactory - The MasterFactory service responsible for controlling the master side replication behaviour.
      Throws:
      StandardException - Standard Derby exception policy, thrown on replication startup error. Will only be thrown if replication is attempted started on a readonly database, i.e, never thrown here.

    • stopReplicationMasterRole

      public void stopReplicationMasterRole()
      Stop this LogFactory from passing log records to the MasterFactory and from notifying the MasterFactory when a log disk flush has taken place.
      Specified by:
      stopReplicationMasterRole in interface LogFactory

    • stopReplicationSlaveRole

      public void stopReplicationSlaveRole() throws StandardException
      Stop the slave functionality for this LogFactory. Calling this method causes the thread currently doing recovery to stop the recovery process and throw a StandardException with SQLState SHUTDOWN_DATABASE. This should only be done when the database will be shutdown.
      Throws:
      StandardException - Standard Derby exception policy
      See Also:

    • checkForReplication

      protected void checkForReplication(LogAccessFile log)
      Used by LogAccessFile to check if it should take the replication master role, and thereby send log records to the MasterFactory.
      Parameters:
      log - The LogAccessFile that will take the replication master role iff this database is master.

    • initializeReplicationSlaveRole

      public void initializeReplicationSlaveRole() throws StandardException
      Initializes logOut so that log received from the replication master can be appended to the log file. Normally, logOut (the file log records are appended to) is set up as part of the recovery process. When the database is booted in replication slave mode, however, recovery will not get to the point where logOut is initialized until this database is no longer in slave mode. Since logOut is needed to append log records received from the master, logOut needs to be set up for replication slave mode. This method finds the last log record in the log file with the highest number. logOut is set up so that log records will be appended to the end of that file, and the endPosition and lastFlush variables are set to point to the end of the same file. All this is normally done as part of recovery. After the first log file switch resulting from applying log received from the master, recovery will be allowed to read up to, but not including, the current log file which is the file numbered logFileNumber. Note that this method must not be called until LogToFile#boot() has completed. Currently, this is ensured because RawStore#boot starts the SlaveFactory (in turn calling this method) after LogFactory.boot() has completed. Race conditions for logFileNumber may occur if this is changed.
      Throws:
      StandardException - Standard Derby error policy

    • failoverSlave

      public void failoverSlave()
      Used to make the slave stop appending log records, complete recovery and boot the database.

    • restoreLogs

      private boolean restoreLogs(Properties properties) throws StandardException
      This function restores logs based on the following attributes are specified on connection URL: Attribute.CREATE_FROM (Create database from backup if it does not exist) Attribute.RESTORE_FROM (Delete the whole database if it exists and then restore it from backup) Attribute.ROLL_FORWARD_RECOVERY_FROM:(Perform Rollforward Recovery; except for the log directory everything else is replaced by the copy from backup. log files in the backup are copied to the existing online log directory. In case of RESTORE_FROM, the whole database directory is removed in Directory.java while restoring service.properties so even the log directory is removed. In case of CREATE_FROM, log directory will not exist if we came so far because it should fail if a database already exists. In case ROLL_FORWARD_RECOVERY_FROM log directory should not be removed. So only thing that needs to be done here is create a a log directory if it does not exists and copy the log files(including control files) that exists in the backup from which we are are trying to restore the database to the online log directory.
      Throws:
      StandardException

    • preAllocateNewLogFile

      private void preAllocateNewLogFile(StorageRandomAccessFile log) throws IOException, StandardException
      Throws:
      IOException
      StandardException

    • openLogFileInWriteMode

      private StorageRandomAccessFile openLogFileInWriteMode(StorageFile logFile) throws IOException
      open the given log file name for writes; if file can not be be opened in write sync mode then disable the write sync mode and open the file in "rw" mode.
      Throws:
      IOException

    • getLogDirPath

      private String getLogDirPath(StorageFile logDir)

    • checkJvmSyncError

      private boolean checkJvmSyncError(StorageFile logFile) throws IOException
      In Java 1.4.2 and newer rws and rwd modes for RandomAccessFile are supported. Still, on some JVMs (e.g. early versions of 1.4.2 and 1.5 on Mac OS and FreeBSD) the support for rws and rwd is not working. This method attempts to detect this by opening an existing file in "rws" mode. If this fails, Derby should fall back to use "rw" mode for the log files followed by explicit syncing of the log. Note: it is important to use "rws" for the test. If "rwd" is used, no exception is thrown when opening the file, but the syncing does not take place. For more details see DERBY-1 (and DERBY-2020).
      Parameters:
      logFile - information about the log file to be opened
      Returns:
      true if a JVM error is detected, false otherwise
      Throws:
      StandardException - Standard Derby exception
      IOException

    • privExists

      protected boolean privExists(StorageFile file)

    • privDelete

      protected boolean privDelete(StorageFile file)

    • privRandomAccessFile

      private StorageRandomAccessFile privRandomAccessFile(StorageFile file, String perms) throws IOException
      Throws:
      IOException

    • privGetOutputStreamWriter

      private OutputStreamWriter privGetOutputStreamWriter(StorageFile file) throws IOException
      Throws:
      IOException

    • privCanWrite

      protected boolean privCanWrite(StorageFile file)

    • privMkdirs

      protected boolean privMkdirs(StorageFile file) throws IOException
      Throws:
      IOException

    • privList

      private String[] privList(File file)

    • privList

      private String[] privList(StorageFile file)

    • privCopyFile

      private boolean privCopyFile(StorageFile from, File to) throws StandardException
      Throws:
      StandardException

    • privCopyFile

      private boolean privCopyFile(File from, StorageFile to)

    • privRemoveDirectory

      private boolean privRemoveDirectory(StorageFile file)

    • runBooleanAction

      private boolean runBooleanAction(int action, StorageFile file)

    • setEndPosition

      private void setEndPosition(long newPosition)
      set the endPosition of the log and make sure the new position won't spill off the end of the log

    • run

      public final Object run() throws IOException, StandardException
      Specified by:
      run in interface PrivilegedExceptionAction<Object>
      Throws:
      IOException
      StandardException

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • getContextService

      private static ContextService getContextService()
      Privileged lookup of the ContextService. Must be private so that user code can't call this entry point.

    • getMonitor

      private static ModuleFactory getMonitor()
      Privileged Monitor lookup. Must be private so that user code can't call this entry point.

    • findServiceModule

      private static Object findServiceModule(Object serviceModule, String factoryInterface) throws StandardException
      Privileged startup. Must be private so that user code can't call this entry point.
      Throws:
      StandardException

    • getServiceModule

      private static Object getServiceModule(Object serviceModule, String factoryInterface)
      Privileged module lookup. Must be private so that user code can't call this entry point.

    • isFullUpgrade

      private static boolean isFullUpgrade(Properties startParams, String oldVersionInfo) throws StandardException
      Privileged startup. Must be private so that user code can't call this entry point.
      Throws:
      StandardException