org.corfudb.infrastructure

Class SequencerServerCache

java.lang.Object

org.corfudb.infrastructure.SequencerServerCache

public class SequencerServerCache
extends Object

Sequencer server cache. Contains transaction conflict-resolution data structures.

The SequencerServer use its own thread/s. To guarantee correct tx conflict-resolution, the conflictCache must be updated along with maxConflictWildcard at the same time (atomically) to prevent race condition when the conflict stream is already evicted from the cache but `maxConflictWildcard` is not updated yet, which can cause situation when sequencer let the transaction go but the tx has to be cancelled.

SequencerServerCache achieves consistency by using single threaded cache. It's done by following code: `.executor(Runnable::run)`

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SequencerServerCache.ConflictTxStream Contains the conflict hash code for a stream ID and conflict param.

Constructor Summary

Constructors

Constructor and Description
SequencerServerCache(long cacheSize) The cache limited by size.
SequencerServerCache(long cacheSize, com.github.benmanes.caffeine.cache.CacheWriter<SequencerServerCache.ConflictTxStream,Long> writer)

Method Summary

Modifier and Type	Method and Description
Long	getIfPresent(SequencerServerCache.ConflictTxStream conflictKey) Returns the value associated with the key in this cache, or null if there is no cached value for the key.
void	invalidateAll() Discard all entries in the cache
void	invalidateUpTo(long trimMark) Invalidate all records up to a trim mark.
void	put(SequencerServerCache.ConflictTxStream conflictStream, long newTail) Put a value in the cache
long	size() The cache size
void	updateMaxConflictAddress(long newMaxConflictWildcard) Update max conflict wildcard by a new address

Methods inherited from class java.lang.Object

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

Constructor Detail

SequencerServerCache

public SequencerServerCache(long cacheSize,
                            com.github.benmanes.caffeine.cache.CacheWriter<SequencerServerCache.ConflictTxStream,Long> writer)

SequencerServerCache

public SequencerServerCache(long cacheSize)

The cache limited by size. For a synchronous cache we are using a same-thread executor (Runnable::run) https://github.com/ben-manes/caffeine/issues/90

Parameters:

cacheSize - cache size

Method Detail

getIfPresent

public Long getIfPresent(SequencerServerCache.ConflictTxStream conflictKey)

Returns the value associated with the key in this cache, or null if there is no cached value for the key.

Parameters:

conflictKey - conflict stream

Returns:

global address

invalidateUpTo

public void invalidateUpTo(long trimMark)

Invalidate all records up to a trim mark.

Parameters:

trimMark - trim mark

size

public long size()

The cache size

Returns:

cache size

put

public void put(SequencerServerCache.ConflictTxStream conflictStream,
                long newTail)

Put a value in the cache

Parameters:

conflictStream - conflict stream

newTail - global tail

invalidateAll

public void invalidateAll()

Discard all entries in the cache

updateMaxConflictAddress

public void updateMaxConflictAddress(long newMaxConflictWildcard)

Update max conflict wildcard by a new address

Parameters:

newMaxConflictWildcard - new conflict wildcard