io.aeron.cluster.service

Class RecoveryState

java.lang.Object

io.aeron.cluster.service.RecoveryState

public final class RecoveryState
extends Object

Counter representing the Recovery State for the cluster.

Key layout as follows:

   0                   1                   2                   3
   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  |                     Leadership Term ID                        |
  |                                                               |
  +---------------------------------------------------------------+
  |                  Log position for Snapshot                    |
  |                                                               |
  +---------------------------------------------------------------+
  |              Timestamp at beginning of Recovery               |
  |                                                               |
  +---------------------------------------------------------------+
  |                         Cluster ID                            |
  +---------------------------------------------------------------+
  |                     Count of Services                         |
  +---------------------------------------------------------------+
  |             Snapshot Recording ID (Service ID 0)              |
  |                                                               |
  +---------------------------------------------------------------+
  |             Snapshot Recording ID (Service ID n)              |
  |                                                               |
  +---------------------------------------------------------------+
 

Field Summary

Fields

Modifier and Type	Field and Description
static int	CLUSTER_ID_OFFSET
static int	LEADERSHIP_TERM_ID_OFFSET
static int	LOG_POSITION_OFFSET
static String	NAME Human readable name for the counter.
static int	RECOVERY_STATE_TYPE_ID Type id of a recovery state counter.
static int	SERVICE_COUNT_OFFSET
static int	SNAPSHOT_RECORDING_IDS_OFFSET
static int	TIMESTAMP_OFFSET

Method Summary

Modifier and Type	Method and Description
static Counter	allocate(Aeron aeron, long leadershipTermId, long logPosition, long timestamp, int clusterId, long... snapshotRecordingIds) Allocate a counter to represent the snapshot services should load on start.
static int	findCounterId(CountersReader counters, int clusterId) Find the active counter id for recovery state.
static long	getLeadershipTermId(CountersReader counters, int counterId) Get the leadership term id for the snapshot state.
static long	getLogPosition(CountersReader counters, int counterId) Get the position at which the snapshot was taken.
static long	getSnapshotRecordingId(CountersReader counters, int counterId, int serviceId) Get the recording id of the snapshot for a service.
static long	getTimestamp(CountersReader counters, int counterId) Get the timestamp at the beginning of recovery.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

RECOVERY_STATE_TYPE_ID

public static final int RECOVERY_STATE_TYPE_ID

Type id of a recovery state counter.

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Constant Field Values

NAME

public static final String NAME

Human readable name for the counter.

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Constant Field Values

LEADERSHIP_TERM_ID_OFFSET

public static final int LEADERSHIP_TERM_ID_OFFSET

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Constant Field Values

LOG_POSITION_OFFSET

public static final int LOG_POSITION_OFFSET

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Constant Field Values

TIMESTAMP_OFFSET

public static final int TIMESTAMP_OFFSET

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Constant Field Values

CLUSTER_ID_OFFSET

public static final int CLUSTER_ID_OFFSET

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Constant Field Values

SERVICE_COUNT_OFFSET

public static final int SERVICE_COUNT_OFFSET

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Constant Field Values

SNAPSHOT_RECORDING_IDS_OFFSET

public static final int SNAPSHOT_RECORDING_IDS_OFFSET

See Also:

Constant Field Values

Method Detail

allocate

public static Counter allocate(Aeron aeron,
                               long leadershipTermId,
                               long logPosition,
                               long timestamp,
                               int clusterId,
                               long... snapshotRecordingIds)

Allocate a counter to represent the snapshot services should load on start.

Parameters:

aeron - to allocate the counter.

leadershipTermId - at which the snapshot was taken.

logPosition - at which the snapshot was taken.

timestamp - the snapshot was taken.

clusterId - which identifies the cluster instance.

snapshotRecordingIds - for the services to use during recovery indexed by service id.

Returns:

the Counter for the recovery state.

findCounterId

public static int findCounterId(CountersReader counters,
                                int clusterId)

Find the active counter id for recovery state.

Parameters:

counters - to search within.

clusterId - to constrain the search.

Returns:

the counter id if found otherwise CountersReader.NULL_COUNTER_ID.

getLeadershipTermId

public static long getLeadershipTermId(CountersReader counters,
                                       int counterId)

Get the leadership term id for the snapshot state. Aeron.NULL_VALUE if no snapshot for recovery.

Parameters:

counters - to search within.

counterId - for the active recovery counter.

Returns:

the leadership term id if found otherwise Aeron.NULL_VALUE.

getLogPosition

public static long getLogPosition(CountersReader counters,
                                  int counterId)

Get the position at which the snapshot was taken. Aeron.NULL_VALUE if no snapshot for recovery.

Parameters:

counters - to search within.

counterId - for the active recovery counter.

Returns:

the log position if found otherwise Aeron.NULL_VALUE.

getTimestamp

public static long getTimestamp(CountersReader counters,
                                int counterId)

Get the timestamp at the beginning of recovery. Aeron.NULL_VALUE if no snapshot for recovery.

Parameters:

counters - to search within.

counterId - for the active recovery counter.

Returns:

the timestamp if found otherwise Aeron.NULL_VALUE.

getSnapshotRecordingId

public static long getSnapshotRecordingId(CountersReader counters,
                                          int counterId,
                                          int serviceId)

Get the recording id of the snapshot for a service.

Parameters:

counters - to search within.

counterId - for the active recovery counter.

serviceId - for the snapshot required.

Returns:

the count of replay terms if found otherwise Aeron.NULL_VALUE.