Package org.apache.activemq.store.kahadb.scheduler

Class JobSchedulerStoreImpl

    • Constructor Detail

      • JobSchedulerStoreImpl

        public JobSchedulerStoreImpl()

    • Method Detail

      • getJobScheduler

        public JobScheduler getJobScheduler​(String name)
                             throws Exception
        Description copied from interface: JobSchedulerStore
        Returns the JobScheduler instance identified by the given name.
        Specified by:
        getJobScheduler in interface JobSchedulerStore
        Parameters:
        name - the name of the JobScheduler instance to lookup.
        Returns:
        the named JobScheduler or null if none exists with the given name.
        Throws:
        Exception - if an error occurs while loading the named scheduler.

      • removeJobScheduler

        public boolean removeJobScheduler​(String name)
                           throws Exception
        Description copied from interface: JobSchedulerStore
        Removes the named JobScheduler if it exists, purging all scheduled messages assigned to it.
        Specified by:
        removeJobScheduler in interface JobSchedulerStore
        Parameters:
        name - the name of the scheduler instance to remove.
        Returns:
        true if there was a scheduler with the given name to remove.
        Throws:
        Exception - if an error occurs while removing the scheduler.

      • setLegacyStoreArchiveDirectory

        public void setLegacyStoreArchiveDirectory​(File directory)
        Sets the directory where the legacy scheduler store files are archived before an update attempt is made. Both the legacy index files and the journal files are moved to this folder prior to an upgrade attempt.
        Parameters:
        directory - The directory to move the legacy Scheduler Store files to.

      • getLegacyStoreArchiveDirectory

        public File getLegacyStoreArchiveDirectory()
        Gets the directory where the legacy Scheduler Store files will be archived if the broker is started and an existing Job Scheduler Store from an old version is detected.
        Returns:
        the directory where scheduler store legacy files are archived on upgrade.

      • load

        public void load()
          throws IOException
        Description copied from class: AbstractKahaDBStore
        Loads the store from disk. Based on configuration this method can either load an existing store or it can purge an existing store and start in a clean state.
        Specified by:
        load in class AbstractKahaDBStore
        Throws:
        IOException - if an error occurs during the load.

      • unload

        public void unload()
            throws IOException
        Description copied from class: AbstractKahaDBStore
        Unload the state of the Store to disk and shuts down all resources assigned to this KahaDB store implementation.
        Specified by:
        unload in class AbstractKahaDBStore
        Throws:
        IOException - if an error occurs during the store unload.

      • checkpointUpdate

        protected void checkpointUpdate​(Transaction tx,
                                boolean cleanup)
                         throws IOException
        Description copied from class: AbstractKahaDBStore
        Perform the checkpoint update operation. If the cleanup flag is true then the operation should also purge any unused Journal log files. This method must always be called with the checkpoint and index write locks held.
        Specified by:
        checkpointUpdate in class AbstractKahaDBStore
        Parameters:
        tx - The TX under which to perform the checkpoint update.
        cleanup - Should the checkpoint also do unused Journal file cleanup.
        Throws:
        IOException - if an error occurs while performing the checkpoint.

      • incrementJournalCount

        protected void incrementJournalCount​(Transaction tx,
                                     Location location)
                              throws IOException
        Adds a reference for the journal log file pointed to by the given Location value. To prevent log files in the journal that still contain valid data that needs to be kept in order to allow for recovery the logs must have active references. Each Job scheduler should ensure that the logs are accurately referenced.
        Parameters:
        tx - The TX under which the update is to be performed.
        location - The location value to update the reference count of.
        Throws:
        IOException - if an error occurs while updating the journal references table.

      • decrementJournalCount

        protected void decrementJournalCount​(Transaction tx,
                                     Location location)
                              throws IOException
        Removes one reference for the Journal log file indicated in the given Location value. The references are used to track which log files cannot be GC'd. When the reference count on a log file reaches zero the file id is removed from the tracker and the log will be removed on the next check point update.
        Parameters:
        tx - The TX under which the update is to be performed.
        location - The location value to update the reference count of.
        Throws:
        IOException - if an error occurs while updating the journal references table.

      • decrementJournalCount

        protected void decrementJournalCount​(Transaction tx,
                                     HashMap<Integer,​Integer> decrementsByFileIds)
                              throws IOException
        Removes multiple references for the Journal log file indicated in the given Location map. The references are used to track which log files cannot be GC'd. When the reference count on a log file reaches zero the file id is removed from the tracker and the log will be removed on the next check point update.
        Parameters:
        tx - The TX under which the update is to be performed.
        decrementsByFileIds - Map indicating how many decrements per fileId.
        Throws:
        IOException - if an error occurs while updating the journal references table.

      • referenceRemovedLocation

        protected void referenceRemovedLocation​(Transaction tx,
                                        Location location,
                                        org.apache.activemq.store.kahadb.scheduler.JobLocation removedJob)
                                 throws IOException
        Updates the Job removal tracking index with the location of a remove command and the original JobLocation entry. The JobLocation holds the locations in the logs where the add and update commands for a job stored. The log file containing the remove command can only be discarded after both the add and latest update log files have also been discarded.
        Parameters:
        tx - The TX under which the update is to be performed.
        location - The location value to reference a remove command.
        removedJob - The original JobLocation instance that holds the add and update locations
        Throws:
        IOException - if an error occurs while updating the remove location tracker.

      • referenceRemovedLocation

        protected void referenceRemovedLocation​(Transaction tx,
                                        Location location,
                                        List<Integer> removedJobsFileId)
                                 throws IOException
        Updates the Job removal tracking index with the location of a remove command and the original JobLocation entry. The JobLocation holds the locations in the logs where the add and update commands for a job stored. The log file containing the remove command can only be discarded after both the add and latest update log files have also been discarded.
        Parameters:
        tx - The TX under which the update is to be performed.
        location - The location value to reference a remove command.
        removedJobsFileId - List of the original JobLocation instances that holds the add and update locations
        Throws:
        IOException - if an error occurs while updating the remove location tracker.

      • getPayload

        protected ByteSequence getPayload​(Location location)
                           throws IOException
        Retrieve the scheduled Job's byte blob from the journal.
        Parameters:
        location - The location of the KahaAddScheduledJobCommand that originated the Job.
        Returns:
        a ByteSequence containing the payload of the scheduled Job.
        Throws:
        IOException - if an error occurs while reading the payload value.

      • readLockIndex

        public void readLockIndex()

      • readUnlockIndex

        public void readUnlockIndex()

      • writeLockIndex

        public void writeLockIndex()

      • writeUnlockIndex

        public void writeUnlockIndex()

      • doRecover

        protected void doRecover​(JournalCommand<?> data,
                         Location location,
                         Location inDoubtlocation)
                  throws IOException
        Called during index recovery to rebuild the index from the last known good location. For entries that occur before the last known good position we just ignore then and move on.
        Parameters:
        data - the command read from the Journal which should be used to update the index.
        location - the location in the index where the command was read.
        inDoubtlocation - the location in the index known to be the last time the index was valid.
        Throws:
        IOException - if an error occurs while recovering the index.

      • process

        protected void process​(JournalCommand<?> data,
                       Location location)
                throws IOException
        Called during recovery to allow the store to rebuild from scratch.
        Specified by:
        process in class AbstractKahaDBStore
        Parameters:
        data - The command to process, which was read from the Journal.
        location - The location of the command in the Journal.
        Throws:
        IOException - if an error occurs during command processing.

      • processLocation

        protected void processLocation​(Location location)