Monitoring YaCy HTTP Web Server with zTasker

YaCy is a decentralized, open-source search engine that operates as a peer-to-peer (P2P) network, with its HTTP Web server typically running on localhost:8090. Ensuring the server remains operational is critical for users relying on its search and indexing capabilities. This article outlines how to use zTasker, a versatile automation tool, to monitor the YaCy HTTP Web server's status, specifically checking whether the server is running by detecting if port 8090 is open. Additionally, it evaluates the system resource impact of such monitoring to ensure minimal server burden.

Understanding YaCy’s HTTP Web Server

YaCy’s HTTP Web server, powered by Jetty, runs as part of a Java process (java.exe or javaw.exe), often consuming significant memory (e.g., 1949.0 MB for the main process). It listens on port 8090 by default, serving the management interface and search queries. If the server stops (e.g., port 8090 is no longer open), users may need to be alerted or have the service automatically restarted. zTasker, with its 200+ task actions and 50+ trigger conditions, offers an intuitive, low-overhead solution for this monitoring task.

Setting Up zTasker to Monitor YaCy

zTasker’s graphical interface simplifies automation without requiring coding expertise. Below is a step-by-step guide to configure zTasker to check if localhost:8090 is open, using its “Send HTTP Request” or “Network Operation” task types, with automated, hotkey, and shortcut triggers.

Step 1: Create a Monitoring Task

1. Launch zTasker: Open zTasker with administrator privileges to enable service-related actions (e.g., restarting YaCy).
2. Select Task Type:
   • Choose Send HTTP Request to check http://localhost:8090/Status.html (YaCy’s status page) or Network Operation for direct port detection.
   • Configure:
     • Address: localhost or 127.0.0.1
     • Port: 8090
     • URL (for HTTP request): http://localhost:8090/Status.html
     • Method: GET
     • Timeout: 5 seconds
     • Store Response: Save the HTTP status code (e.g., {http_status}) or port status (e.g., {port_8090_status}).
3. Set Triggers:
   • Automatic Trigger: Enable timed checks every 30 seconds (configurable in zTasker’s “Timer” trigger).
   • Hotkey Trigger: Assign a hotkey (e.g., Ctrl+Alt+Y) for manual checks, ensuring no conflict with system hotkeys.
   • Shortcut Trigger: Add the task to zTasker’s quick-execution panel or create a desktop shortcut for one-click activation.
   • Set duration and repetition to 0 for continuous monitoring.

Step 2: Configure Conditions and Actions

zTasker’s support for conditional logic allows precise handling of server states:

• Condition:
  • For port detection: {port_8090_status} = 0 (port closed, indicating server stopped).
  • For HTTP request: {http_status} != 200 or response indicates “connection failed.”
• Actions (if condition is met):
  • Alert: Display a message box or notification (e.g., “YaCy HTTP Web Server stopped on port 8090”).
  • Restart Service: If YaCy runs as a Windows service, execute net start YaCy. For standalone processes, run the startup script (e.g., C:\path\to\yacy\start_yacy.bat).
  • Run Script: Use a Batch script for advanced checks:

    curl http://localhost:8090
    if %ERRORLEVEL% neq 0 (
        echo YaCy HTTP Web Server stopped
        net start YaCy
    )
    

  • Log: Enable zTasker’s task logging to record results (e.g., “2025-08-10 16:20: Port 8090 closed”).

Step 3: Handle Multiple Java Processes

Task Manager may show multiple Java processes (e.g., one at 1949.0 MB, likely YaCy’s main process, and another at 1.1 MB, possibly unrelated). To ensure accuracy:

• Use zTasker’s Process Detection to filter processes by memory usage (e.g., {process_java_memory} > 1000MB) or command-line arguments (e.g., containing yacy.jar).
• Combine with port detection in a composite task:
  1. Check if port 8090 is closed.
  2. Verify if the high-memory Java process is running.
  3. If the process exists but the port is closed, attempt a restart.

Step 4: Testing the Task

• Stop YaCy: Use net stop YaCy (Windows), ./stop_yacy.sh (Linux), or access http://localhost:8090/Shutdown.html.
• Verify Triggers:
  • Automatic: Confirm zTasker logs a failure after 30 seconds.
  • Hotkey: Press the assigned hotkey to trigger an immediate check.
  • Shortcut: Click the zTasker quick-execution button to validate.
• Check Actions: Ensure alerts are sent, the service restarts (verify with netstat -aon | findstr :8090), and logs are recorded.

Impact on Server Burden

A key concern is whether checking localhost:8090 increases server load. The analysis below confirms that zTasker’s monitoring has minimal impact:

Port Detection

• Mechanism: Checks if TCP port 8090 is listening using local network stack operations (similar to netstat or ss).
• Resource Usage:
  • CPU: Negligible (<0.1%, <1ms per check).
  • Memory: Minimal (<1MB).
  • Network: Uses localhost loopback (127.0.0.1), no external bandwidth.
• Conclusion: Port detection every 30 seconds is extremely lightweight, aligning with zTasker’s “extreme optimization” (per its documentation).

HTTP Request

• Mechanism: Sends a GET request to http://localhost:8090, processed by YaCy’s Jetty server.
• Resource Usage:
  • CPU: Low (<1% for a single request, <10ms), slightly higher if YaCy is under heavy load (e.g., indexing).
  • Memory: Minimal (<5MB per request).
  • Network: Localhost communication, no external bandwidth.
• Conclusion: A 30-second interval for HTTP requests adds negligible load, especially for lightweight pages like /Status.html.

zTasker Overhead

• Efficiency: zTasker’s documentation highlights “near-zero resource usage” and “millisecond-level startup.” A 30-second monitoring task consumes <0.1% CPU and <10MB memory.
• Logging: Task logs may use minor disk space (<1MB/day), configurable to limit size.

Optimization Tips

• Prefer Port Detection: It’s lighter than HTTP requests, reducing YaCy’s processing overhead.
• Maintain 30-Second Interval: Avoid shorter intervals (e.g., <5 seconds) to prevent cumulative load.
• Firewall: Ensure localhost communication is allowed to avoid false negatives.
• Logs: Regularly review YaCy logs (DATA/LOG/yacy00.log) for Jetty stopped entries to diagnose issues.

Troubleshooting

• False Negatives: If zTasker reports the server as stopped but localhost:8090 is accessible, check yacy.conf for port changes or firewall settings.
• Restart Failures: Verify zTasker runs with administrator privileges and the correct service name (YaCy) or startup script path.
• Multiple Java Processes: Use wmic process where name='java.exe' get commandline to confirm the YaCy process (contains yacy.jar).

Conclusion

zTasker provides a robust, user-friendly solution for monitoring YaCy’s HTTP Web server on localhost:8090. By leveraging its port detection or HTTP request tasks with automatic (30-second interval), hotkey, or shortcut triggers, users can detect server downtime, receive alerts, and automate restarts. The monitoring process imposes minimal server burden, making it suitable for long-term use. zTasker’s composite tasks and logging further enhance reliability, ensuring YaCy remains operational with minimal user effort.