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 get)
request goes directly to the searcher, meaning it is
non-realtime.Engine.CommitId, Engine.Create, Engine.Delete, Engine.DeleteByQuery, Engine.FailedEngineListener, Engine.Get, Engine.GetResult, Engine.Index, Engine.IndexingOperation, Engine.IndexThrottle, Engine.NoOpLock, Engine.Operation, Engine.Searcher, Engine.SyncedFlushResult
Modifier and Type | Field and Description |
---|---|
static TimeValue |
DEFAULT_NONEXISTENT_INDEX_RETRY_WAIT |
static String |
NONEXISTENT_INDEX_RETRY_WAIT
how long to wait for an index to exist
|
deletionPolicy, engineConfig, failedEngine, failedEngineListener, failEngineLock, isClosed, logger, readLock, rwl, shardId, store, SYNC_COMMIT_ID, writeLock
Constructor and Description |
---|
ShadowEngine(EngineConfig engineConfig) |
Modifier and Type | Method and Description |
---|---|
protected void |
closeNoLock(String reason)
Method to close the engine while the write lock is held.
|
void |
create(Engine.Create create) |
void |
delete(Engine.Delete delete) |
void |
delete(Engine.DeleteByQuery delete)
Deprecated.
This was removed, but we keep this API so translog can replay any DBQs on upgrade.
|
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) |
protected org.apache.lucene.index.SegmentInfos |
getLastCommittedSegmentInfos() |
protected org.apache.lucene.search.SearcherManager |
getSearcherManager() |
Translog |
getTranslog()
returns the translog for this engine
|
boolean |
hasUncommittedChanges()
Returns
true the internal writer has any uncommitted changes. |
boolean |
index(Engine.Index index) |
long |
indexWriterRAMBytesUsed()
How much heap Lucene's IndexWriter is using
|
void |
refresh(String source)
Refreshes the engine for new search operations to reflect the latest
changes.
|
List<Segment> |
segments(boolean verbose)
The list of segments in the engine.
|
SnapshotIndexCommit |
snapshotIndex(boolean flushFirst)
Snapshots the index and returns a handle to it.
|
Engine.SyncedFlushResult |
syncFlush(String syncId,
Engine.CommitId expectedCommitId)
Attempts to do a special commit where the given syncID is put into the commit data.
|
acquireSearcher, acquireSearcher, close, commitStats, config, ensureOpen, failEngine, flushAndClose, forceMerge, getFromSearcher, getMergeStats, getSegmentInfo, guardedRamBytesUsed, isMergedSegment, maybeFailEngine, newSearcher, onSettingsChanged, readLastCommittedSegmentInfos, refreshNeeded, segmentReader, segmentsStats, wrapIfClosed, writerSegmentStats
public static final String NONEXISTENT_INDEX_RETRY_WAIT
public static final TimeValue DEFAULT_NONEXISTENT_INDEX_RETRY_WAIT
public ShadowEngine(EngineConfig engineConfig)
public void create(Engine.Create create) throws EngineException
create
in class Engine
EngineException
public boolean index(Engine.Index index) throws EngineException
index
in class Engine
EngineException
public void delete(Engine.Delete delete) throws EngineException
delete
in class Engine
EngineException
@Deprecated public void delete(Engine.DeleteByQuery delete) throws EngineException
delete
in class Engine
EngineException
public Engine.SyncedFlushResult syncFlush(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) throws EngineException
get
in class Engine
EngineException
public Translog getTranslog()
Engine
getTranslog
in class Engine
public List<Segment> segments(boolean verbose)
Engine
public void refresh(String source) throws EngineException
Engine
refresh
in class Engine
EngineException
public SnapshotIndexCommit snapshotIndex(boolean flushFirst) throws EngineException
Engine
snapshotIndex
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(String reason)
Engine
closeNoLock
in class Engine
public boolean hasUncommittedChanges()
Engine
true
the internal writer has any uncommitted changes. Otherwise false
hasUncommittedChanges
in class Engine
protected org.apache.lucene.index.SegmentInfos getLastCommittedSegmentInfos()
getLastCommittedSegmentInfos
in class Engine
public long indexWriterRAMBytesUsed()
Engine
indexWriterRAMBytesUsed
in class Engine
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