final String value = params.get(key);
        if (value == null) {
            return key;
        }
        return value;
    }

    /**
     * Thread to monitor and terminate processes that exceed the timeout.
     */
    protected static class MonitorThread extends Thread {
        private final Process process;

        private final long timeout;

<logger name="org.codelibs.fess.crawler.client" level="DEBUG"/>
<logger name="org.codelibs.fess.crawler.extractor" level="DEBUG"/>
```

### Monitoring

```java
// Monitor crawling progress
while (crawler.crawlerContext.getStatus() == CrawlerStatus.RUNNING) {
    int processed = dataService.getCount(sessionId);
    System.out.println("Processed: " + processed + " URLs");
    Thread.sleep(5000);

**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
- Use streaming for large data imports

### Debug Logging

Enable debug logging for detailed troubleshooting:

```java
// Add to your logging configuration