public class ShadowEngine extends Engine
IndexReader
is opened instead of
an IndexWriter
. All methods that would usually perform write
operations are no-ops, this means:
- No operations are written to or read from the translog
- Create, Index, and Delete do nothing
- Flush does not fsync any files, or make any on-disk changes
In order for new segments to become visible, the ShadowEngine may perform
stage1 of the traditional recovery process (copying segment files) from a
regular primary (which uses InternalEngine
)
Notice that since this Engine does not deal with the translog, any
Engine.get(Get, Function)
request goes directly to the searcher,
meaning it is non-realtime.Engine.CommitId, Engine.Delete, Engine.DeleteResult, Engine.EventListener, Engine.Get, Engine.GetResult, Engine.Index, Engine.IndexResult, Engine.IndexThrottle, Engine.NoOpLock, Engine.Operation, Engine.Result, Engine.Searcher, Engine.SyncedFlushResult, Engine.Warmer
Modifier and Type | Field and Description |
---|---|
static TimeValue |
DEFAULT_NONEXISTENT_INDEX_RETRY_WAIT |
static java.lang.String |
NONEXISTENT_INDEX_RETRY_WAIT
how long to wait for an index to exist
|
deletionPolicy, engineConfig, eventListener, failedEngine, failEngineLock, isClosed, lastWriteNanos, logger, readLock, rwl, shardId, store, SYNC_COMMIT_ID, writeLock
Constructor and Description |
---|
ShadowEngine(EngineConfig engineConfig) |
Modifier and Type | Method and Description |
---|---|
org.apache.lucene.index.IndexCommit |
acquireIndexCommit(boolean flushFirst)
Snapshots the index and returns a handle to it.
|
void |
activateThrottling()
Request that this engine throttle incoming indexing requests to one thread.
|
protected void |
closeNoLock(java.lang.String reason,
java.util.concurrent.CountDownLatch closedLatch)
Method to close the engine while the write lock is held.
|
void |
deactivateThrottling()
Reverses a previous
Engine.activateThrottling() call. |
Engine.DeleteResult |
delete(Engine.Delete delete)
Perform document delete operation on the engine
|
Engine.CommitId |
flush()
Flushes the state of the engine including the transaction log, clearing memory and persisting
documents in the lucene index to disk including a potentially heavy and durable fsync operation.
|
Engine.CommitId |
flush(boolean force,
boolean waitIfOngoing)
Flushes the state of the engine including the transaction log, clearing memory.
|
void |
forceMerge(boolean flush,
int maxNumSegments,
boolean onlyExpungeDeletes,
boolean upgrade,
boolean upgradeOnlyAncientSegments)
Triggers a forced merge on this engine
|
Engine.GetResult |
get(Engine.Get get,
java.util.function.Function<java.lang.String,Engine.Searcher> searcherFacotry) |
long |
getIndexBufferRAMBytesUsed()
How much heap is used that would be freed by a refresh.
|
long |
getIndexThrottleTimeInMillis()
Returns the number of milliseconds this engine was under index throttling.
|
protected org.apache.lucene.index.SegmentInfos |
getLastCommittedSegmentInfos() |
protected org.apache.lucene.search.SearcherManager |
getSearcherManager() |
Translog |
getTranslog()
returns the translog for this engine
|
Engine.IndexResult |
index(Engine.Index index)
Perform document index operation on the engine
|
boolean |
isThrottled()
Returns the
true iff this engine is currently under index throttling. |
Engine |
recoverFromTranslog()
Performs recovery from the transaction log.
|
void |
refresh(java.lang.String source)
Synchronously refreshes the engine for new search operations to reflect the latest
changes.
|
java.util.List<Segment> |
segments(boolean verbose)
The list of segments in the engine.
|
Engine.SyncedFlushResult |
syncFlush(java.lang.String syncId,
Engine.CommitId expectedCommitId)
Attempts to do a special commit where the given syncID is put into the commit data.
|
void |
writeIndexingBuffer()
Called when our engine is using too much heap and should move buffered indexed/deleted documents to disk.
|
acquireSearcher, close, commitStats, config, ensureOpen, failEngine, flushAndClose, forceMerge, getFromSearcher, getLastWriteNanos, getMergeStats, getSegmentInfo, guardedRamBytesUsed, isMergedSegment, isRecovering, maybeFailEngine, newSearcher, onSettingsChanged, readLastCommittedSegmentInfos, refreshNeeded, segmentReader, segmentsStats, writerSegmentStats
public static final java.lang.String NONEXISTENT_INDEX_RETRY_WAIT
public static final TimeValue DEFAULT_NONEXISTENT_INDEX_RETRY_WAIT
public ShadowEngine(EngineConfig engineConfig)
public Engine.IndexResult index(Engine.Index index)
Engine
index
in class Engine
index
- operation to performEngine.IndexResult
containing updated translog location, version and
document specific failures
Note: engine level failures (i.e. persistent engine failures) are thrownpublic Engine.DeleteResult delete(Engine.Delete delete)
Engine
delete
in class Engine
delete
- operation to performEngine.DeleteResult
containing updated translog location, version and
document specific failures
Note: engine level failures (i.e. persistent engine failures) are thrownpublic Engine.SyncedFlushResult syncFlush(java.lang.String syncId, Engine.CommitId expectedCommitId)
Engine
public Engine.CommitId flush() throws EngineException
Engine
flush
in class Engine
EngineException
public Engine.CommitId flush(boolean force, boolean waitIfOngoing) throws EngineException
Engine
flush
in class Engine
force
- if true
a lucene commit is executed even if no changes need to be committed.waitIfOngoing
- if true
this call will block until all currently running flushes have finished.
Otherwise this call will return without blocking.EngineException
public void forceMerge(boolean flush, int maxNumSegments, boolean onlyExpungeDeletes, boolean upgrade, boolean upgradeOnlyAncientSegments) throws EngineException
Engine
forceMerge
in class Engine
EngineException
public Engine.GetResult get(Engine.Get get, java.util.function.Function<java.lang.String,Engine.Searcher> searcherFacotry) throws EngineException
get
in class Engine
EngineException
public Translog getTranslog()
Engine
getTranslog
in class Engine
public java.util.List<Segment> segments(boolean verbose)
Engine
public void refresh(java.lang.String source) throws EngineException
Engine
refresh
in class Engine
EngineException
public org.apache.lucene.index.IndexCommit acquireIndexCommit(boolean flushFirst) throws EngineException
Engine
acquireIndexCommit
in class Engine
flushFirst
- indicates whether the engine should flush before returning the snapshotEngineException
protected org.apache.lucene.search.SearcherManager getSearcherManager()
getSearcherManager
in class Engine
protected void closeNoLock(java.lang.String reason, java.util.concurrent.CountDownLatch closedLatch)
Engine
closeNoLock
in class Engine
protected org.apache.lucene.index.SegmentInfos getLastCommittedSegmentInfos()
getLastCommittedSegmentInfos
in class Engine
public long getIndexBufferRAMBytesUsed()
Engine
AlreadyClosedException
.getIndexBufferRAMBytesUsed
in class Engine
public void writeIndexingBuffer()
Engine
writeIndexingBuffer
in class Engine
public void activateThrottling()
Engine
Engine.deactivateThrottling()
.activateThrottling
in class Engine
public void deactivateThrottling()
Engine
Engine.activateThrottling()
call.deactivateThrottling
in class Engine
public boolean isThrottled()
Engine
true
iff this engine is currently under index throttling.isThrottled
in class Engine
Engine.getIndexThrottleTimeInMillis()
public long getIndexThrottleTimeInMillis()
Engine
getIndexThrottleTimeInMillis
in class Engine
public Engine recoverFromTranslog() throws java.io.IOException
Engine
recoverFromTranslog
in class Engine
java.io.IOException