Package org.apache.hadoop.hdfs.server.namenode

Class JournalSet

java.lang.Object
org.apache.hadoop.hdfs.server.namenode.JournalSet
All Implemented Interfaces:
Closeable, AutoCloseable, Storage.FormatConfirmable, JournalManager
@Private public class JournalSet extends Object implements JournalManager
Manages a collection of Journals. None of the methods are synchronized, it is assumed that FSEditLog methods, that use this class, use proper synchronization.

  • Field Details

  • Method Details

    • format

      public void format(NamespaceInfo nsInfo, boolean force) throws IOException
      Description copied from interface: JournalManager
      Format the underlying storage, removing any previously stored data.
      Specified by:
      format in interface JournalManager
      Throws:
      IOException

    • hasSomeData

      public boolean hasSomeData() throws IOException
      Specified by:
      hasSomeData in interface Storage.FormatConfirmable
      Returns:
      true if the storage seems to have some valid data in it, and the user should be required to confirm the format. Otherwise, false.
      Throws:
      IOException - if the storage cannot be accessed at all.

    • startLogSegment

      public EditLogOutputStream startLogSegment(long txId, int layoutVersion) throws IOException
      Description copied from interface: JournalManager
      Begin writing to a new segment of the log stream, which starts at the given transaction ID.
      Specified by:
      startLogSegment in interface JournalManager
      Throws:
      IOException

    • finalizeLogSegment

      public void finalizeLogSegment(long firstTxId, long lastTxId) throws IOException
      Description copied from interface: JournalManager
      Mark the log segment that spans from firstTxId to lastTxId as finalized and complete.
      Specified by:
      finalizeLogSegment in interface JournalManager
      Throws:
      IOException

    • close

      public void close() throws IOException
      Description copied from interface: JournalManager
      Close the journal manager, freeing any resources it may hold.
      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Closeable
      Specified by:
      close in interface JournalManager
      Throws:
      IOException

    • isOpen

      public boolean isOpen()

    • selectInputStreams

      public void selectInputStreams(Collection<EditLogInputStream> streams, long fromTxId, boolean inProgressOk, boolean onlyDurableTxns)
      In this function, we get a bunch of streams from all of our JournalManager objects. Then we add these to the collection one by one.
      Parameters:
      streams - The collection to add the streams to. It may or may not be sorted-- this is up to the caller.
      fromTxId - The transaction ID to start looking for streams at
      inProgressOk - Should we consider unfinalized streams?
      onlyDurableTxns - Set to true if streams are bounded by the durable TxId. A durable TxId is the committed txid in QJM or the largest txid written into file in FJM

    • chainAndMakeRedundantStreams

      public static void chainAndMakeRedundantStreams(Collection<EditLogInputStream> outStreams, PriorityQueue<EditLogInputStream> allStreams, long fromTxId)

    • isEmpty

      public boolean isEmpty()
      Returns true if there are no journals, all redundant journals are disabled, or any required journals are disabled.
      Returns:
      True if there no journals, all redundant journals are disabled, or any required journals are disabled.

    • setOutputBufferCapacity

      public void setOutputBufferCapacity(int size)
      Description copied from interface: JournalManager
      Set the amount of memory that this stream should use to buffer edits
      Specified by:
      setOutputBufferCapacity in interface JournalManager

    • purgeLogsOlderThan

      public void purgeLogsOlderThan(long minTxIdToKeep) throws IOException
      Throws:
      IOException

    • recoverUnfinalizedSegments

      public void recoverUnfinalizedSegments() throws IOException
      Description copied from interface: JournalManager
      Recover segments which have not been finalized.
      Specified by:
      recoverUnfinalizedSegments in interface JournalManager
      Throws:
      IOException

    • getEditLogManifest

      public RemoteEditLogManifest getEditLogManifest(long fromTxId)
      Return a manifest of what finalized edit logs are available. All available edit logs are returned starting from the transaction id passed. If 'fromTxId' falls in the middle of a log, that log is returned as well.
      Parameters:
      fromTxId - Starting transaction id to read the logs.
      Returns:
      RemoteEditLogManifest object.

    • doPreUpgrade

      public void doPreUpgrade() throws IOException
      Description copied from interface: JournalManager
      Perform any steps that must succeed across all JournalManagers involved in an upgrade before proceeding onto the actual upgrade stage. If a call to any JM's doPreUpgrade method fails, then doUpgrade will not be called for any JM.
      Specified by:
      doPreUpgrade in interface JournalManager
      Throws:
      IOException

    • doUpgrade

      public void doUpgrade(Storage storage) throws IOException
      Description copied from interface: JournalManager
      Perform the actual upgrade of the JM. After this is completed, the NN can begin to use the new upgraded metadata. This metadata may later be either finalized or rolled back to the previous state.
      Specified by:
      doUpgrade in interface JournalManager
      Parameters:
      storage - info about the new upgraded versions.
      Throws:
      IOException

    • doFinalize

      public void doFinalize() throws IOException
      Description copied from interface: JournalManager
      Finalize the upgrade. JMs should purge any state that they had been keeping around during the upgrade process. After this is completed, rollback is no longer allowed.
      Specified by:
      doFinalize in interface JournalManager
      Throws:
      IOException

    • canRollBack

      public boolean canRollBack(StorageInfo storage, StorageInfo prevStorage, int targetLayoutVersion) throws IOException
      Description copied from interface: JournalManager
      Return true if this JM can roll back to the previous storage state, false otherwise. The NN will refuse to run the rollback operation unless at least one JM or fsimage storage directory can roll back.
      Specified by:
      canRollBack in interface JournalManager
      Parameters:
      storage - the storage info for the current state
      prevStorage - the storage info for the previous (unupgraded) state
      targetLayoutVersion - the layout version we intend to roll back to
      Returns:
      true if this JM can roll back, false otherwise.
      Throws:
      IOException

    • doRollback

      public void doRollback() throws IOException
      Description copied from interface: JournalManager
      Perform the rollback to the previous FS state. JMs which do not need to roll back their state should just return without error.
      Specified by:
      doRollback in interface JournalManager
      Throws:
      IOException

    • discardSegments

      public void discardSegments(long startTxId) throws IOException
      Description copied from interface: JournalManager
      Discard the segments whose first txid is >= the given txid.
      Specified by:
      discardSegments in interface JournalManager
      Parameters:
      startTxId - The given txid should be right at the segment boundary, i.e., it should be the first txid of some segment, if segment corresponding to the txid exists.
      Throws:
      IOException

    • getJournalCTime

      public long getJournalCTime() throws IOException
      Specified by:
      getJournalCTime in interface JournalManager
      Returns:
      the CTime of the journal manager.
      Throws:
      IOException