Package org.opendaylight.controller.cluster.raft

Interface ReplicatedLog

All Known Implementing Classes:
AbstractReplicatedLogImpl
public interface ReplicatedLog
Represents the ReplicatedLog that needs to be kept in sync by the RaftActor.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final long
    NO_MAX_SIZE
     

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    append(ReplicatedLogEntry replicatedLogEntry)
    Appends an entry to the log.
    boolean
    appendAndPersist(@NonNull ReplicatedLogEntry replicatedLogEntry, @Nullable Consumer<ReplicatedLogEntry> callback, boolean doAsync)
    Appends an entry to the in-memory log and persists it as well.
    void
    captureSnapshotIfReady(ReplicatedLogEntry replicatedLogEntry)
    Determines if a snapshot needs to be captured based on the count/memory consumed and initiates the capture.
    void
    clear(int startIndex, int endIndex)
    Clears the journal entries with startIndex (inclusive) and endIndex (exclusive).
    int
    dataSize()
    Returns the size of the data in the log (in bytes).
    @Nullable ReplicatedLogEntry
    get(long index)
    Return the replicated log entry at the specified index.
    @NonNull List<ReplicatedLogEntry>
    getFrom(long index)
    Returns a list of log entries starting from the given index to the end of the log.
    @NonNull List<ReplicatedLogEntry>
    getFrom(long index, int maxEntries, long maxDataSize)
    Returns a list of log entries starting from the given index up to the given maximum of entries or the given maximum accumulated size, whichever comes first.
    long
    getSnapshotIndex()
    Returns the index of the snapshot.
    long
    getSnapshotTerm()
    Returns the term of the snapshot.
    void
    increaseJournalLogCapacity(int amount)
    Optimization method to increase the capacity of the journal log prior to appending entries.
    boolean
    isInSnapshot(long index)
    Checks if the entry is present in a snapshot.
    boolean
    isPresent(long index)
    Checks if the entry at the specified index is present or not.
    @Nullable ReplicatedLogEntry
    last()
    Return the last replicated log entry in the log or null of not found.
    long
    lastIndex()
    Return the index of the last entry in the log or -1 if the log is empty.
    long
    lastTerm()
    Return the term of the last entry in the log or -1 if the log is empty.
    long
    removeFrom(long index)
    Removes entries from the in-memory log starting at the given index.
    boolean
    removeFromAndPersist(long index)
    Removes entries from the in-memory log and the persisted log starting at the given index.
    void
    setSnapshotIndex(long snapshotIndex)
    Sets the snapshot index in the replicated log.
    void
    setSnapshotTerm(long snapshotTerm)
    Sets snapshot term.
    boolean
    shouldCaptureSnapshot(long logIndex)
    Determines if a snapshot should be captured based on the count/memory consumed.
    long
    size()
    Returns the number of entries in the journal.
    default void
    snapshotCommit()
    Sets the Replicated log to state after snapshot success.
    void
    snapshotCommit(boolean updateDataSize)
    Sets the Replicated log to state after snapshot success.
    void
    snapshotPreCommit(long snapshotCapturedIndex, long snapshotCapturedTerm)
    Handles all the bookkeeping in order to perform a rollback in the event of SaveSnapshotFailure.
    void
    snapshotRollback()
    Restores the replicated log to a state in the event of a save snapshot failure.

  • Field Details

  • Method Details

    • get

      @Nullable ReplicatedLogEntry get(long index)
      Return the replicated log entry at the specified index.
      Parameters:
      index - the index of the log entry
      Returns:
      the ReplicatedLogEntry if found, otherwise null if the adjusted index less than 0 or greater than the size of the in-memory journal

    • last

      @Nullable ReplicatedLogEntry last()
      Return the last replicated log entry in the log or null of not found.
      Returns:
      the last replicated log entry in the log or null of not found.

    • lastIndex

      long lastIndex()
      Return the index of the last entry in the log or -1 if the log is empty.
      Returns:
      the index of the last entry in the log or -1 if the log is empty.

    • lastTerm

      long lastTerm()
      Return the term of the last entry in the log or -1 if the log is empty.
      Returns:
      the term of the last entry in the log or -1 if the log is empty.

    • removeFrom

      long removeFrom(long index)
      Removes entries from the in-memory log starting at the given index.
      Parameters:
      index - the index of the first log entry to remove
      Returns:
      the adjusted index of the first log entry removed or -1 if the log entry is not found.

    • removeFromAndPersist

      boolean removeFromAndPersist(long index)
      Removes entries from the in-memory log and the persisted log starting at the given index.

      The persisted information would then be used during recovery to properly reconstruct the state of the in-memory replicated log

      Parameters:
      index - the index of the first log entry to remove
      Returns:
      true if entries were removed, false otherwise

    • append

      boolean append(ReplicatedLogEntry replicatedLogEntry)
      Appends an entry to the log.
      Parameters:
      replicatedLogEntry - the entry to append
      Returns:
      true if the entry was successfully appended, false otherwise. An entry can fail to append if the index is already included in the log.

    • increaseJournalLogCapacity

      void increaseJournalLogCapacity(int amount)
      Optimization method to increase the capacity of the journal log prior to appending entries.
      Parameters:
      amount - the amount to increase by

    • appendAndPersist

      boolean appendAndPersist(@NonNull ReplicatedLogEntry replicatedLogEntry, @Nullable Consumer<ReplicatedLogEntry> callback, boolean doAsync)
      Appends an entry to the in-memory log and persists it as well.
      Parameters:
      replicatedLogEntry - the entry to append
      callback - the callback to be notified when persistence is complete (optional).
      doAsync - if true, the persistent actor can receive subsequent messages to process in between the persist call and the execution of the associated callback. If false, subsequent messages are stashed and get delivered after persistence is complete and the associated callback is executed. In either case the callback is guaranteed to execute in the context of the actor associated with this log.
      Returns:
      true if the entry was successfully appended, false otherwise.

    • getFrom

      @NonNull List<ReplicatedLogEntry> getFrom(long index)
      Returns a list of log entries starting from the given index to the end of the log.
      Parameters:
      index - the index of the first log entry to get.
      Returns:
      the List of entries

    • getFrom

      @NonNull List<ReplicatedLogEntry> getFrom(long index, int maxEntries, long maxDataSize)
      Returns a list of log entries starting from the given index up to the given maximum of entries or the given maximum accumulated size, whichever comes first.
      Parameters:
      index - the index of the first log entry to get
      maxEntries - the maximum number of entries to get
      maxDataSize - the maximum accumulated size of the log entries to get
      Returns:
      the List of entries meeting the criteria.

    • size

      long size()
      Returns the number of entries in the journal.
      Returns:
      the number of entries

    • isPresent

      boolean isPresent(long index)
      Checks if the entry at the specified index is present or not.
      Parameters:
      index - the index of the log entry
      Returns:
      true if the entry is present in the in-memory journal

    • isInSnapshot

      boolean isInSnapshot(long index)
      Checks if the entry is present in a snapshot.
      Parameters:
      index - the index of the log entry
      Returns:
      true if the entry is in the snapshot. false if the entry is not in the snapshot even if the entry may be present in the replicated log

    • getSnapshotIndex

      long getSnapshotIndex()
      Returns the index of the snapshot.
      Returns:
      the index from which the snapshot was created. -1 otherwise.

    • getSnapshotTerm

      long getSnapshotTerm()
      Returns the term of the snapshot.
      Returns:
      the term of the index from which the snapshot was created. -1 otherwise

    • setSnapshotIndex

      void setSnapshotIndex(long snapshotIndex)
      Sets the snapshot index in the replicated log.
      Parameters:
      snapshotIndex - the index to set

    • setSnapshotTerm

      void setSnapshotTerm(long snapshotTerm)
      Sets snapshot term.
      Parameters:
      snapshotTerm - the term to set

    • clear

      void clear(int startIndex, int endIndex)
      Clears the journal entries with startIndex (inclusive) and endIndex (exclusive).
      Parameters:
      startIndex - the start index (inclusive)
      endIndex - the end index (exclusive)

    • snapshotPreCommit

      void snapshotPreCommit(long snapshotCapturedIndex, long snapshotCapturedTerm)
      Handles all the bookkeeping in order to perform a rollback in the event of SaveSnapshotFailure.
      Parameters:
      snapshotCapturedIndex - the new snapshot index
      snapshotCapturedTerm - the new snapshot term

    • snapshotCommit

      default void snapshotCommit()
      Sets the Replicated log to state after snapshot success. This method is equivalent to snapshotCommit(true).

    • snapshotCommit

      void snapshotCommit(boolean updateDataSize)
      Sets the Replicated log to state after snapshot success. Most users will want to use snapshotCommit() instead.
      Parameters:
      updateDataSize - true if dataSize() should also be updated

    • snapshotRollback

      void snapshotRollback()
      Restores the replicated log to a state in the event of a save snapshot failure.

    • dataSize

      int dataSize()
      Returns the size of the data in the log (in bytes).
      Returns:
      the size of the data in the log (in bytes)

    • captureSnapshotIfReady

      void captureSnapshotIfReady(ReplicatedLogEntry replicatedLogEntry)
      Determines if a snapshot needs to be captured based on the count/memory consumed and initiates the capture.
      Parameters:
      replicatedLogEntry - the last log entry.

    • shouldCaptureSnapshot

      boolean shouldCaptureSnapshot(long logIndex)
      Determines if a snapshot should be captured based on the count/memory consumed.
      Parameters:
      logIndex - the log index to use to determine if the log count has exceeded the threshold
      Returns:
      true if a snapshot should be captured, false otherwise