Package org.apache.bookkeeper.bookie.storage.directentrylogger

Enum Events

  • All Implemented Interfaces:
    java.io.Serializable, java.lang.Comparable<Events>
    public enum Events
extends java.lang.Enum<Events>
    Events.

    • Enum Constant Detail

      • FALLOCATE_NOT_AVAILABLE

        public static final Events FALLOCATE_NOT_AVAILABLE
        Fallocate is not available on this host. This generally indicates that the process is running on a non-Linux operating system. The lack of fallocate means that the filesystem will have to do more bookkeeping as data is written to the file, which will slow down writes.

      • ENTRYLOG_IDS_CANDIDATES_SELECTED

        public static final Events ENTRYLOG_IDS_CANDIDATES_SELECTED
        EntryLog ID candidates selected. These are the set entry log ID that subsequent entry log files will use. To find the candidates, the bookie lists all the log ids which have already been used, and finds the longest contiguous block of free ids. Over the lifetime of a bookie, a log id can be reused. This is not a problem, as the ids are only referenced from the index, and an entry log file will not be deleted if there are still references to it in the index. Generally candidates are selected at bookie boot, but they may also be selected at a later time if the current set of candidates is depleted.

      • ENTRYLOGGER_CREATED

        public static final Events ENTRYLOGGER_CREATED
        The entrylogger(EntryLogger) has been created. This occurs during bookie bootup, and the same entry logger will be used for the duration of the bookie process's lifetime.

      • ENTRYLOGGER_MISCONFIGURED

        public static final Events ENTRYLOGGER_MISCONFIGURED
        The entrylogger has been configured in a way that will likely result in errors during operation.

      • LOG_ROLL

        public static final Events LOG_ROLL
        The entrylogger has started writing a new log file. The previous log file may not be entirely flushed when this is called, though they will be after an explicit flush call.

      • LOG_DELETED

        public static final Events LOG_DELETED
        A log file has been deleted. This happens as a result of GC, when all entries in the file belong to deleted ledgers, or compaction, where the live entries have been copied to a new log.

      • READER_CLOSE_ERROR

        public static final Events READER_CLOSE_ERROR
        An error occurred closing an entrylog reader. This is non-fatal but it may leak the file handle and the memory buffer of the reader in question.

      • READ_METADATA_FALLBACK

        public static final Events READ_METADATA_FALLBACK
        An attempt to read entrylog metadata failed. Falling back to scanning the log to get the metadata. This can occur if a bookie crashes before closing the entrylog cleanly.

      • COMPACTION_LOG_CREATED

        public static final Events COMPACTION_LOG_CREATED
        A new entrylog has been created. The filename has the format [dstLogId].compacting, where dstLogId is a new unique log ID. Entrylog compaction will copy live entries from an existing src log to this new compacting destination log. There is a 1-1 relationship between source logs and destination log logs. Once the copy completes, the compacting log will be marked as compacted by renaming the file to [dstLogId].log.[srcLogId].compacted, where srcLogId is the ID of the entrylog from which the live entries were copied. A new hardlink, [dstLogId].log, is created to point to the same inode, making the entry log available to be read. The compaction algorithm then updates the index with the offsets of the entries in the compacted destination log. Once complete, the index is flushed and all intermediate files (links) are deleted along with the original source log file. The entry copying phase of compaction is expensive. The renaming and linking in the algorithm exists so if a failure occurs after copying has completed, the work will not need to be redone.

      • COMPACTION_LOG_RECOVERED

        public static final Events COMPACTION_LOG_RECOVERED
        A partially compacted log has been recovered. The log file is of the format [dstLogId].log.[srcLogId].compacted. The log will be scanned and the index updated with the offsets of the entries in the log. Once complete, the log with ID srcLogId is deleted.

        See COMPACTION_LOG_CREATED for more information on compaction.

      • COMPACTION_MARK_COMPACTED

        public static final Events COMPACTION_MARK_COMPACTED
        A compaction log has been marked as compacted. A log is marked as compacted by renaming from [dstLogId].log to [dstLogId].log.[srcLogId].compacted. All live entries from the src log have been successfully copied to the destination log, at this point.

        See COMPACTION_LOG_CREATED for more information on compaction.

      • COMPACTION_MAKE_AVAILABLE

        public static final Events COMPACTION_MAKE_AVAILABLE
        A compacted log has been made available for reads. A log is made available by creating a hardlink pointing from [dstLogId].log, to [dstLogId].log.[srcLogId].compacted. These files, pointing to the same inode, will continue to exist until the compaction operation is complete.

        A reader with a valid offset will now be able to read from this log, so the index can be updated.

        See COMPACTION_LOG_CREATED for more information on compaction.

      • COMPACTION_COMPLETE

        public static final Events COMPACTION_COMPLETE
        Compaction has been completed for a log. All intermediatory files are deleted, along with the src entrylog file.

        See COMPACTION_LOG_CREATED for more information on compaction.

      • COMPACTION_ABORT_EXCEPTION

        public static final Events COMPACTION_ABORT_EXCEPTION
        Failed to delete files while aborting a compaction operation. While this is not fatal, it can mean that there are issues writing to the filesystem that need to be investigated.

      • COMPACTION_DELETE_FAILURE

        public static final Events COMPACTION_DELETE_FAILURE
        Failed to delete files while completing a compaction operation. While this is not fatal, it can mean that there are issues writing to the filesystem that need to be investigated.

    • Method Detail

      • values

        public static Events[] values()
        Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows: 
        for (Events c : Events.values())
    System.out.println(c);
        Returns:
        an array containing the constants of this enum type, in the order they are declared

      • valueOf

        public static Events valueOf​(java.lang.String name)
        Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)
        Parameters:
        name - the name of the enum constant to be returned.
        Returns:
        the enum constant with the specified name
        Throws:
        java.lang.IllegalArgumentException - if this enum type has no constant with the specified name
        java.lang.NullPointerException - if the argument is null