com.hazelcast.spi.hotrestart

Interface HotRestartStore

All Known Implementing Classes:

ConcurrentHotRestartStore

public interface HotRestartStore

Persistent store of key-value mappings specifically tailored to support the Hot Restart feature. Supports only update operations and no data lookup. Data retrieval happens only during the hot restart procedure, when this store pushes data to its associated RAM stores.

Update operations (put/remove/clear) accept a "needs fsync" parameter which determines the persistence semantics of the operation (immediate vs. eventual). For each given key prefix the value of this parameter must always be the same because the Hot Restart Store will group a batch of operations by the "needs fsync" value. Order within each group is preserved.

Field Summary

Fields

Modifier and Type	Field and Description
static String	LOG_CATEGORY The name of the log category used by the Hot Restart module

Method Summary

Modifier and Type	Method and Description
void	backup(File targetDir) Copies the contents of this hot restart store to the target directory.
void	clear(boolean needsFsync, long... keyPrefixes) Removes all mappings for the supplied list of key prefixes.
void	close() Closes this Hot Restart store and releases any system resources it had acquired.
com.hazelcast.hotrestart.BackupTaskState	getBackupTaskState() Returns the state of the hot restart backup task
void	hotRestart(boolean failIfAnyData, int storeCount, com.hazelcast.internal.util.concurrent.ConcurrentConveyor<RestartItem>[] keyConveyors, com.hazelcast.internal.util.concurrent.ConcurrentConveyor<RestartItem> keyHandleConveyor, com.hazelcast.internal.util.concurrent.ConcurrentConveyor<RestartItem>[] valueConveyors) Performs hot restart: reads the data from persistent storage and pushes it to its associated RamStoreRegistry.
void	interruptBackupTask() Interrupts the backup task if one is currently running.
String	name() Returns the store's name, which matches the name of its home directory.
void	put(HotRestartKey key, byte[] value, boolean needsFsync) Establishes a persistent mapping from the supplied key to the supplied value.
void	remove(HotRestartKey key, boolean needsFsync) Removes the persistent mapping for the supplied key.

Field Detail

LOG_CATEGORY

static final String LOG_CATEGORY

The name of the log category used by the Hot Restart module

See Also:

Constant Field Values

Method Detail

name

String name()

Returns the store's name, which matches the name of its home directory.

hotRestart

void hotRestart(boolean failIfAnyData,
                int storeCount,
                com.hazelcast.internal.util.concurrent.ConcurrentConveyor<RestartItem>[] keyConveyors,
                com.hazelcast.internal.util.concurrent.ConcurrentConveyor<RestartItem> keyHandleConveyor,
                com.hazelcast.internal.util.concurrent.ConcurrentConveyor<RestartItem>[] valueConveyors)
         throws InterruptedException

Performs hot restart: reads the data from persistent storage and pushes it to its associated RamStoreRegistry.

Parameters:

failIfAnyData - if true, the call will fail if any persistent data is found

storeCount - the number of Hot Restart stores associated with the Hazelcast instance

keyConveyors - convey keys from HotRestartStore to RamStore

valueConveyors - convey values from HotRestartStore to RamStore

keyHandleConveyor - conveys key handles from RamStore to HotRestartStore

Throws:

InterruptedException

put

void put(HotRestartKey key,
         byte[] value,
         boolean needsFsync)
  throws HotRestartException

Establishes a persistent mapping from the supplied key to the supplied value.

This method must not be called while holding a lock that can block the progress of RamStore.copyEntry(KeyHandle, int, RecordDataSink) on any RamStore which can be returned by the RamStoreRegistry associated with this Hot Restart store.

Parameters:

needsFsync - if true, the currently active chunk will be fsync'd before closing. If this parameter is false, there is no guarantee that a later call to #fsync() will make this operation persistent.

Throws:

HotRestartException

remove

void remove(HotRestartKey key,
            boolean needsFsync)
     throws HotRestartException

Removes the persistent mapping for the supplied key.

This method must not be called while holding a lock that can block the progress of RamStore.copyEntry(KeyHandle, int, RecordDataSink) on any RamStore which can be returned by the RamStoreRegistry associated with this Hot Restart store.

Parameters:

needsFsync - if true, the currently active chunk will be fsync'd before closing. If this parameter is false, there is no guarantee that a later call to #fsync() will make this operation persistent.

Throws:

HotRestartException

clear

void clear(boolean needsFsync,
           long... keyPrefixes)
    throws HotRestartException

Removes all mappings for the supplied list of key prefixes.

This method must not be called while holding a lock that can block the progress of RamStore.copyEntry(KeyHandle, int, RecordDataSink) on any RamStore which can be returned by the RamStoreRegistry associated with this Hot Restart store.

Parameters:

needsFsync - has no effect on the semantics of persistence, but its value must match the "needs fsync" configuration of all supplied key prefixes

keyPrefixes - the key prefixes whose data is to be cleared

Throws:

HotRestartException

close

void close()
    throws HotRestartException

Closes this Hot Restart store and releases any system resources it had acquired. The store will permit no further operations on it.

This method must not be called while holding a lock that can block the progress of RamStore.copyEntry(KeyHandle, int, RecordDataSink) on any RamStore which can be returned by the RamStoreRegistry associated with this Hot Restart store.

Throws:

HotRestartException

backup

void backup(File targetDir)

Copies the contents of this hot restart store to the target directory. This method will return as soon as copying has started. Further copying will be done after this method has returned.

Parameters:

targetDir - the directory under which backups for the stores will be created

getBackupTaskState

com.hazelcast.hotrestart.BackupTaskState getBackupTaskState()

Returns the state of the hot restart backup task

interruptBackupTask

void interruptBackupTask()

Interrupts the backup task if one is currently running. The contents of the target backup directory will be left as-is