如何配置Hibernate Search 5.9工作线程池大小

我目前正在进行一个项目,我们将hibernate search升级到5.9.2版本(从3.4.2)。我们在lucene 5.5.5和spring boot 1.5中使用hibernate搜索。我们使用的是Hibernate5.2.17版本。

在实体管理器配置JPA属性中设置了以下属性:

properties.put("hibernate.search.default.worker.thread_pool.size", "5");

不过,这个属性似乎没有任何效果。在调试期间,我注意到在hibernate search的“lazyexecutorholder”中,executor服务以null开始,并以1的线程池大小初始化。以下是Hibernate Search的代码片段:

package org.hibernate.search.backend.impl.lucene;
final class LazyExecutorHolder {

/**
 * Lazily initialized; state change protected by executorStateWriteLock
 */

private ExecutorService asyncIndexingExecutor;

public void submitTask(LuceneBackendQueueTask task) {
    executorStateReadLock.lock();
    try {
        final ExecutorService executor = asyncIndexingExecutor;
        if ( executor != null ) {
            executor.submit( task );
            return; // !
        }
    }
    finally {
        executorStateReadLock.unlock();
    }
    //If not returned yet, means the executor wasn't available;
    //Needs to be started within the exclusive lock.
    executorStateWriteLock.lock();
    try {
        ExecutorService executor = asyncIndexingExecutor;
        if ( executor == null ) {
            executor = Executors.newFixedThreadPool( 1, threadNamePrefix, maxQueueLength );
            this.asyncIndexingExecutor = executor;
        }
        executor.submit( task );
    }
    finally {
        executorStateWriteLock.unlock();
    }
}
...........

此属性是否已重命名/删除?我们可以用其他方法配置lucene工作线程池的大小吗?我在hibernate搜索文档中找不到任何关于删除的内容。升级hibernate和hibernate search后,我们当前的性能正在下降。