});
```

## Performance Tuning

### Thread Configuration

```java
// Optimize thread pool settings
crawler.crawlerContext.setNumOfThread(20);           // Number of crawler threads
crawler.crawlerContext.setMaxThreadCheckCount(50);   // Thread monitoring frequency
```

### Connection Pool Tuning

```java
container.singleton("httpClient", HcHttpClient.class, client -> {

			<artifactId>commons-net</artifactId>
			<version>${commons.net.version}</version>
		</dependency>
		<dependency>
			<groupId>org.apache.commons</groupId>
			<artifactId>commons-pool2</artifactId>
			<version>${commons.pool2.version}</version>
		</dependency>
		<dependency>
			<groupId>com.google.guava</groupId>
			<artifactId>guava</artifactId>
			<version>${guava.version}</version>
		</dependency>
		<dependency>

 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.crawler.pool;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;

import org.apache.commons.pool2.PooledObject;
import org.apache.commons.pool2.impl.DefaultPooledObject;
import org.codelibs.fess.crawler.container.StandardCrawlerContainer;

 *   <li>{@link #popularWords()}: Creates a new PopularWordsRequestBuilder for querying popular words.</li>
 *   <li>{@link #refresh()}: Refreshes the suggestion indices.</li>
 *   <li>{@link #shutdown()}: Shuts down the thread pool.</li>
 *   <li>{@link #createIndexIfNothing()}: Creates a new index if no index exists.</li>
 *   <li>{@link #createNextIndex()}: Creates a new index and replaces the current update alias with the new index.</li>

 * <li>{@link #analyzer} - Suggest analyzer.
 * <li>{@link #contentsParser} - Contents parser.
 * <li>{@link #suggestWriter} - Suggest writer.
 * <li>{@link #threadPool} - Executor service for thread pool.
 * </ul>
 */
public class SuggestIndexer {
    private final static Logger logger = LogManager.getLogger(SuggestIndexer.class);

    /** The suggest analyzer. */
    protected SuggestAnalyzer analyzer;

            }
            logger.info("Disconnected to {}", address);
        }
        connected = false;
    }

    /**
     * Gets the thread pool from the underlying client.
     *
     * @return The thread pool.
     */
    @Override
    public ThreadPool threadPool() {
        return client.threadPool();
    }

    /**

**Suggestions Not Appearing**
- Confirm documents are indexed: `suggester.refresh()`
- Check query formatting and filters
- Verify analyzer configurations

**Performance Issues**
- Increase thread pool size in SuggesterBuilder
- Optimize batch sizes for indexing operations
- Review OpenSearch cluster performance

**Memory Usage**
- Configure appropriate JVM heap settings
- Monitor index sizes and optimize mappings

            if (logger.isDebugEnabled()) {
                logger.debug("Offered URL: Session ID: {}, UrlQueue: {}", sessionId, targetList);
            }
        }
    }

    /**
     * Polls the next URL queue entry for the specified session.
     * This method manages local caches and fetches from OpenSearch when needed.
     *
     * @param sessionId The session ID.