public class ConcurrentMergeScheduler extends MergeScheduler
MergeScheduler
that runs each merge using a
separate thread.
Specify the max number of threads that may run at
once, and the maximum number of simultaneous merges
with setMaxMergesAndThreads(int, int)
.
If the number of merges exceeds the max number of threads then the largest merges are paused until one of the smaller merges completes.
If more than getMaxMergeCount()
merges are
requested then this class will forcefully throttle the
incoming threads by pausing until one more more merges
complete.
Modifier and Type | Field and Description |
---|---|
static int |
DEFAULT_MAX_MERGE_COUNT
Default
maxMergeCount . |
static int |
DEFAULT_MAX_THREAD_COUNT
Default
maxThreadCount . |
Constructor and Description |
---|
ConcurrentMergeScheduler()
Sole constructor, with all settings set to default
values.
|
Modifier and Type | Method and Description |
---|---|
MergeScheduler |
clone() |
void |
close()
Close this MergeScheduler.
|
int |
getMaxMergeCount()
|
int |
getMaxThreadCount()
Returns
maxThreadCount . |
int |
getMergeThreadPriority()
Return the priority that merge threads run at.
|
void |
merge(IndexWriter writer)
Run the merges provided by
IndexWriter.getNextMerge() . |
void |
setMaxMergesAndThreads(int maxMergeCount,
int maxThreadCount)
Sets the maximum number of merge threads and simultaneous merges allowed.
|
void |
setMergeThreadPriority(int pri)
Set the base priority that merge threads run at.
|
void |
sync()
Wait for any running merge threads to finish.
|
String |
toString() |
public static final int DEFAULT_MAX_THREAD_COUNT
maxThreadCount
.
We default to 1: tests on spinning-magnet drives showed slower
indexing performance if more than one merge thread runs at
once (though on an SSD it was faster)public static final int DEFAULT_MAX_MERGE_COUNT
maxMergeCount
.public ConcurrentMergeScheduler()
public void setMaxMergesAndThreads(int maxMergeCount, int maxThreadCount)
maxMergeCount
- the max # simultaneous merges that are allowed.
If a merge is necessary yet we already have this many
threads running, the incoming thread (that is calling
add/updateDocument) will block until a merge thread
has completed. Note that we will only run the
smallest maxThreadCount
merges at a time.maxThreadCount
- the max # simultaneous merge threads that should
be running at once. This must be <= maxMergeCount
public int getMaxThreadCount()
maxThreadCount
.setMaxMergesAndThreads(int, int)
public int getMaxMergeCount()
public int getMergeThreadPriority()
public void setMergeThreadPriority(int pri)
public void close()
MergeScheduler
close
in interface Closeable
close
in interface AutoCloseable
close
in class MergeScheduler
public void sync()
close()
.public void merge(IndexWriter writer) throws IOException
MergeScheduler
IndexWriter.getNextMerge()
.merge
in class MergeScheduler
IOException
public MergeScheduler clone()
clone
in class MergeScheduler
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