How to use

setMaxMergesAndThreads

method

in

org.apache.lucene.index.ConcurrentMergeScheduler

private IndexWriterCount createWriter(final File indexDirectory) throws IOException {
  final List<Closeable> closeables = new ArrayList<>();
  final Directory directory = FSDirectory.open(indexDirectory);
  closeables.add(directory);
  try {
    final Analyzer analyzer = new StandardAnalyzer();
    closeables.add(analyzer);
    final IndexWriterConfig config = new IndexWriterConfig(LuceneUtil.LUCENE_VERSION, analyzer);
    final ConcurrentMergeScheduler mergeScheduler = new ConcurrentMergeScheduler();
    final int mergeThreads = repoConfig.getConcurrentMergeThreads();
    mergeScheduler.setMaxMergesAndThreads(mergeThreads, mergeThreads);
    config.setMergeScheduler(mergeScheduler);
    final IndexWriter indexWriter = new IndexWriter(directory, config);
    final EventIndexWriter eventIndexWriter = new LuceneEventIndexWriter(indexWriter, indexDirectory);
    final IndexWriterCount writerCount = new IndexWriterCount(eventIndexWriter, analyzer, directory, 1, false);
    logger.debug("Providing new index writer for {}", indexDirectory);
    return writerCount;
  } catch (final IOException ioe) {
    for (final Closeable closeable : closeables) {
      try {
        closeable.close();
      } catch (final IOException ioe2) {
        ioe.addSuppressed(ioe2);
      }
    }
    throw ioe;
  }
}

int maxThreadCount = config.get("concurrent.merge.scheduler.max.thread.count", ConcurrentMergeScheduler.AUTO_DETECT_MERGES_AND_THREADS);
int maxMergeCount = config.get("concurrent.merge.scheduler.max.merge.count", ConcurrentMergeScheduler.AUTO_DETECT_MERGES_AND_THREADS);
cms.setMaxMergesAndThreads(maxMergeCount, maxThreadCount);

cms.setMaxMergesAndThreads(maxMergeCount, maxThreadCount);
if (random().nextBoolean()) {
 cms.disableAutoIOThrottle();
cms.setMaxMergesAndThreads(3, 1);
c.setMergeScheduler(cms);

 cms.disableAutoIOThrottle();
cms.setMaxMergesAndThreads(maxMergeCount, maxThreadCount);
didChange = true;

case CONCURRENT:
  mergeScheduler = new ConcurrentMergeScheduler();
  ((ConcurrentMergeScheduler) mergeScheduler).setMaxMergesAndThreads(MERGE_SCHEDULER_SSD_THREADS,
      MERGE_SCHEDULER_SSD_THREADS);
  break;