PartitionTxUpdateCounterImpl (Ignite 2.8.0)

java.lang.Object
- org.apache.ignite.internal.processors.cache.PartitionTxUpdateCounterImpl

All Implemented Interfaces:

Iterable<long[]>, PartitionUpdateCounter

Direct Known Subclasses:

PartitionMvccTxUpdateCounterImpl, PartitionTxUpdateCounterDebugWrapper
```
public class PartitionTxUpdateCounterImpl
extends Object
implements PartitionUpdateCounter
```
Update counter implementation used for transactional cache groups in persistent mode.
Implements new partition update counter flow to avoid situations when:
1. update counter could be incremented and persisted while corresponding update is not recorded to WAL.
2. update counter could be prematurely incremented causing missed rebalancing.
All these situations are sources of partitions desync.
Below a short description of new flow:
1. Update counter is reserved for each update in partition on tx prepare phase (which always happens on primary partition owner). Reservation causes HWM increment.
2. Reserved counter values are propagated on backup nodes and stored in backup transactions.
3. On commit reserved counters are assigned to cache entries.
4. LWM is incremented ONLY after corresponding WAL data record for each entry was written.
5. In case of rollback (manual or during tx recovery on node failure) reserved updates are also applied and logged to WAL using RollbackRecord for further recovery purposes.

Field Summary

Fields
Modifier and Type Field and Description

static int MAX_MISSED_UPDATES
Max allowed missed updates.

protected AtomicLong reserveCntr
HWM.

Fields
Modifier and Type	Field and Description
`static int`	`MAX_MISSED_UPDATES` Max allowed missed updates.
`protected AtomicLong`	`reserveCntr` HWM.

Constructor Summary

Constructors
Constructor and Description

PartitionTxUpdateCounterImpl()

Constructors
Constructor and Description
`PartitionTxUpdateCounterImpl()`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`boolean`	`empty()`
`boolean`	`equals(Object o)`
`GridLongList`	`finalizeUpdateCounters()` Flushes pending update counters closing all possible gaps.
`long`	`get()` Get LWM.
`@Nullable byte[]`	`getBytes()`
`protected long`	`highestAppliedCounter()`
`void`	`init(long initUpdCntr, @Nullable byte[] cntrUpdData)` Restores update counter state.
`long`	`initial()`
`Iterator<long[]>`	`iterator()`
`long`	`next()` Increment LWM by 1.
`long`	`next(long delta)` Increment LWM by delta.
`long`	`reserve(long delta)` Increment HWM by delta.
`long`	`reserved()` Returns HWM.
`void`	`reset()` Reset counter internal state to zero.
`boolean`	`sequential()`
`String`	`toString()`
`void`	`update(long val)` Sets update counter to absolute value.
`boolean`	`update(long start, long delta)` Applies counter update out of range.
`void`	`updateInitial(long start, long delta)`

Methods inherited from class java.lang.Object
clone, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.lang.Iterable
forEach, spliterator

- Field Detail
  - MAX_MISSED_UPDATES
```
public static final int MAX_MISSED_UPDATES
```
    Max allowed missed updates. Overflow will trigger critical failure handler to prevent OOM.
    
    See Also:
    
    Constant Field Values
  - reserveCntr
```
protected final AtomicLong reserveCntr
```
    HWM.
- Constructor Detail
  - PartitionTxUpdateCounterImpl
```
public PartitionTxUpdateCounterImpl()
```
- Method Detail
  - init
```
public void init(long initUpdCntr,
                 @Nullable
                 @Nullable byte[] cntrUpdData)
```
    Restores update counter state.
    
    Specified by:
    
    init in interface PartitionUpdateCounter
    
    Parameters:
    
    initUpdCntr - LWM.
    
    cntrUpdData - Counter updates raw data.
  - initial
```
public long initial()
```
    Specified by:
    
    initial in interface PartitionUpdateCounter
  - get
```
public long get()
```
    Get LWM.
    
    Specified by:
    
    get in interface PartitionUpdateCounter
    
    Returns:
    
    Current LWM.
  - highestAppliedCounter
```
protected long highestAppliedCounter()
```
  - next
```
public long next()
```
    Description copied from interface: PartitionUpdateCounter
    
    Increment LWM by 1.
    
    Specified by:
    
    next in interface PartitionUpdateCounter
    
    Returns:
    
    Next update counter. For tx mode called by DataStreamerImpl IsolatedUpdater.
  - update
```
public void update(long val)
            throws IgniteCheckedException
```
    Sets update counter to absolute value. All missed updates will be discarded.
    
    Specified by:
    
    update in interface PartitionUpdateCounter
    
    Parameters:
    
    val - Absolute value.
    
    Throws:
    
    IgniteCheckedException - if counter cannot be set to passed value due to incompatibility with current state.
  - update
```
public boolean update(long start,
                      long delta)
```
    Applies counter update out of range. Update ranges must not intersect.
    
    Specified by:
    
    update in interface PartitionUpdateCounter
    
    Parameters:
    
    start - Start (<= lwm).
    
    delta - Delta.
    
    Returns:
    
    True if update was actually applied.
  - updateInitial
```
public void updateInitial(long start,
                          long delta)
```
    Specified by:
    
    updateInitial in interface PartitionUpdateCounter
    
    Parameters:
    
    start - Counter.
    
    delta - Delta.
  - finalizeUpdateCounters
```
public GridLongList finalizeUpdateCounters()
```
    Flushes pending update counters closing all possible gaps.
    
    Specified by:
    
    finalizeUpdateCounters in interface PartitionUpdateCounter
    
    Returns:
    
    Even-length array of pairs [start, end] for each gap.
  - reserve
```
public long reserve(long delta)
```
    Increment HWM by delta.
    
    Specified by:
    
    reserve in interface PartitionUpdateCounter
    
    Parameters:
    
    delta - Delta.
    
    Returns:
    
    New HWM.
  - next
```
public long next(long delta)
```
    Increment LWM by delta.
    
    Specified by:
    
    next in interface PartitionUpdateCounter
    
    Parameters:
    
    delta - Delta.
    
    Returns:
    
    New LWM.
  - sequential
```
public boolean sequential()
```
    Specified by:
    
    sequential in interface PartitionUpdateCounter
    
    Returns:
    
    True if counter has no missed updates.
  - getBytes
```
@Nullable
public @Nullable byte[] getBytes()
```
    Specified by:
    
    getBytes in interface PartitionUpdateCounter
  - reset
```
public void reset()
```
    Reset counter internal state to zero.
    
    Specified by:
    
    reset in interface PartitionUpdateCounter
  - equals
```
public boolean equals(Object o)
```
    Overrides:
    
    equals in class Object
  - reserved
```
public long reserved()
```
    Returns HWM.
    
    Specified by:
    
    reserved in interface PartitionUpdateCounter
    
    Returns:
    
    Current HWM.
  - empty
```
public boolean empty()
```
    Specified by:
    
    empty in interface PartitionUpdateCounter
    
    Returns:
    
    True if counter has not seen any update.
  - iterator
```
public Iterator<long[]> iterator()
```
    Specified by:
    
    iterator in interface Iterable<long[]>
    
    Specified by:
    
    iterator in interface PartitionUpdateCounter
    
    Returns:
    
    Iterator for pairs [start, range] for each out-of-order update in the update counter sequence.
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object

Class PartitionTxUpdateCounterImpl

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface java.lang.Iterable

Field Detail

MAX_MISSED_UPDATES

reserveCntr

Constructor Detail

PartitionTxUpdateCounterImpl

Method Detail

init

initial

get

highestAppliedCounter

next

update

update

updateInitial

finalizeUpdateCounters

reserve

next

sequential

getBytes

reset

equals

reserved

empty

iterator

toString