// Should work even if RDMA provider is not available
    file.createNewFile();
    assertTrue(file.exists());
}
```

## 8. Performance Monitoring

### 8.1 RDMA Statistics
```java
public class RdmaStatistics {
    private final AtomicLong rdmaReads = new AtomicLong();
    private final AtomicLong rdmaWrites = new AtomicLong();

import org.opensearch.monitor.os.OsProbe;
import org.opensearch.monitor.os.OsStats;
import org.opensearch.monitor.process.ProcessProbe;

/**
 * This class is a timer target for monitoring system-level statistics.
 * It collects and logs information about the operating system, process,
 * JVM, and search engine.
 */
public class SystemMonitorTarget extends MonitorTarget {

/**
 * Helper class for crawler logging operations.
 * Extends LogHelperImpl to provide specialized logging functionality for crawler operations,
 * including failure URL tracking and crawler statistics integration.
 */
public class CrawlerLogHelper extends LogHelperImpl {

    /**
     * Creates a new instance of CrawlerLogHelper.
     */
    public CrawlerLogHelper() {
        super();
    }

import org.opensearch.search.aggregations.bucket.terms.Terms.Bucket;
import org.opensearch.search.aggregations.bucket.terms.TermsAggregationBuilder;

/**
 * Helper class for managing crawling information and statistics.
 * Provides functionality to track crawling sessions, manage document expiration,
 * and handle crawling information storage and retrieval.
 */
public class CrawlingInfoHelper {

    /**

import java.util.Map;

/**
 * A response list that extends List functionality and includes pagination and search metadata.
 * This class wraps search results with pagination information, facet responses, and query statistics.
 * It implements the List interface to provide standard list operations while adding search-specific
 * functionality such as page navigation, record counts, and query execution times.
 */

        }
    }

    /**
     * Sends email notification with crawling results and statistics.
     * The email contains detailed information about the crawling session including
     * execution times, index sizes, and status information.
     *
     * @param infoMap map containing crawling session information and statistics
     */
    protected void sendMail(final Map<String, String> infoMap) {

        // Validate notification signature/source
        return true;  // Simplified
    }
}
```

## 11. Monitoring and Metrics

### 11.1 Witness Statistics
```java
public class WitnessStatistics {
    private final AtomicLong registrationsActive = new AtomicLong();
    private final AtomicLong notificationsReceived = new AtomicLong();

    public static final String USER_CODE = "userCode";

    /** Search query field name for logging. */
    public static final String SEARCH_FIELD_LOG_SEARCH_QUERY = "q";

    /** Statistics report type parameter name. */
    public static final String STATS_REPORT_TYPE = "reportType";

    /** Result document ID cache key. */
    public static final String RESULT_DOC_ID_CACHE = "resultDocIds";

        }
        
        // Fall back to direct server query
        return directory.performDirectEnumeration();
    }
}
```

## 10. Monitoring and Metrics

### 10.1 Directory Cache Statistics
```java
public class DirectoryCacheStatistics {
    private final AtomicLong cacheHits = new AtomicLong();
    private final AtomicLong cacheMisses = new AtomicLong();

     *   <li>Manages concurrent execution based on thread count limits</li>
     *   <li>Monitors thread completion and handles cleanup</li>
     *   <li>Records execution timing and statistics</li>
     * </ul>
     *
     * @param sessionId unique identifier for this crawling session
     * @param configList list of data configurations to crawl
     */