@Override
public synchronized void merge(IndexWriter writer, MergeTrigger trigger, boolean newMergesFound)
throws IOException {
assert !Thread.holdsLock(writer);
initDynamicDefaults(writer);
if (trigger == MergeTrigger.CLOSING) {
// Disable throttling on close:
targetMBPerSec = MAX_MERGE_MB_PER_SEC;
updateMergeThreads();
}
// First, quickly run through the newly proposed merges
// and add any orthogonal merges (ie a merge not
// involving segments already pending to be merged) to
// the queue. If we are way behind on merging, many of
// these newly proposed merges will likely already be
// registered.
if (verbose()) {
message("now merge");
message(" index: " + writer.segString());
}
// Iterate, pulling from the IndexWriter's queue of
// pending merges, until it's empty:
while (true) {
if (maybeStall(writer) == false) {
break;
}
OneMerge merge = writer.getNextMerge();
if (merge == null) {
if (verbose()) {
message(" no more merges pending; now return");
}
return;
}
updateIOThrottle(merge);
boolean success = false;
try {
if (verbose()) {
message(" consider merge " + writer.segString(merge.segments));
}
// OK to spawn a new merge thread to handle this
// merge:
final MergeThread merger = getMergeThread(writer, merge);
mergeThreads.add(merger);
if (verbose()) {
message(" launch new thread [" + merger.getName() + "]");
}
merger.start();
updateMergeThreads();
success = true;
} finally {
if (!success) {
writer.mergeFinish(merge);
}
}
}
}
/**
* Turn on dynamic IO throttling, to adaptively rate limit writes bytes/sec to the minimal rate
* necessary so merges do not fall behind. By default this is enabled.
*/
public synchronized void enableAutoIOThrottle() {
doAutoIOThrottle = true;
targetMBPerSec = START_MB_PER_SEC;
updateMergeThreads();
}
/**
* Turn off auto IO throttling.
*
* @see #enableAutoIOThrottle
*/
public synchronized void disableAutoIOThrottle() {
doAutoIOThrottle = false;
updateMergeThreads();
}
/**
* Set the per-merge IO throttle rate for forced merges (default: {@code
* Double.POSITIVE_INFINITY}).
*/
public synchronized void setForceMergeMBPerSec(double v) {
forceMergeMBPerSec = v;
updateMergeThreads();
}
