Zenoh Explorer

A standalone native GUI application for exploring, debugging, and monitoring Zenoh networks.

Overview

Zenoh Explorer is a network debugging tool built specifically for Zenoh networks. It provides a graphical interface to:

• Subscribe to key expressions and monitor real-time data flows
• Publish data to the network for testing and debugging
• TODO: Query specific data from the network
• Browse the network data topology in real-time
• TODO: Monitor all network activity with filtering and search capabilities

Features

Core Functionality

• Real-time Network Monitoring: View all messages flowing through the Zenoh network
  • Configurable memory and message limits
  • Rate limiting to prevent UI flooding (configurable 10-10000 msg/s)
  • Accurate memory usage tracking
• Interactive Subscriptions: Subscribe to key expressions with wildcards and patterns
  • Multiple concurrent subscriptions
  • Clean cancellation support
  • Visual subscription status
• Data Publishing: Send test data to any key in the network
  • Support for different encodings
  • Immediate visual feedback
• TODO: Query Interface: Request data from the network with configurable timeouts
  • Note: Requires queryable services on the network
  • Configurable timeout (default: 5 seconds)
• Network Browser: Explore the hierarchical structure of keys and data
  • Tree-based visualization
  • Shows last received payload and message count
  • Auto-expanding navigation

User Interface

• Native Rust GUI: Built with egui for native performance
• Dark/Light Mode: Toggle between themes for comfortable viewing
  • Optimized color schemes for readability
  • Consistent visual hierarchy
• Message Filtering: Search and filter network messages in real-time
• Auto-scroll: Automatically follow new messages as they arrive
• Tabbed Interface: Organized workflow with dedicated tabs for each function
• Health Monitoring: Visual indicators for connection and worker status
  • Connection status badge
  • Worker health indicator (green = healthy, yellow = unresponsive)
• Performance Controls: Adjustable limits directly from the UI
  • Memory limit slider (10-1000 MB)
  • Message count slider (100-50000)
  • Rate limit slider (10-10000 msg/s)

Connection Options

• Client Mode: Connect as a Zenoh client to existing routers
• Peer Mode: Participate as a peer in the mesh network
• Flexible Locators: Support for TCP, UDP, and other transport protocols
• Custom Configuration: Advanced Zenoh configuration via JSON

Installation

Prerequisites

• Rust 1.70 or later

Building from Source

git clone <repository-url>
cd zenoh-explorer
cargo build --release

Running

cargo run --release

The application will start with a default configuration connecting to tcp/localhost:7447.

Usage

Getting Started

1. Launch the Application: Run the executable or use cargo run
2. Configure Connection:
   • Set the locator (e.g., tcp/192.168.1.100:7447)
   • Choose connection mode (Client or Peer)
   • Click "Connect"
3. Start Exploring: Use the tabs to subscribe, publish, query, or browse the network

Tabs Overview

Subscribe Tab

• Enter key expressions to listen for data (e.g., sensors/**, device/*/status)
• View active subscriptions
• Unsubscribe from specific key expressions

Publish Tab

• Send data to any key in the network
• Specify payload content and encoding
• Test network connectivity and data flow

Query Tab

• Request data from specific selectors
• Set custom timeout values
• Include optional query payloads

Browse Tab

• Explore the network's hierarchical key structure
• See recently received data for each key
• Expand/collapse tree nodes for navigation

Messages Tab

• View all network activity in chronological order
• Filter messages by key or content
• Clear message history
• Toggle auto-scroll for real-time monitoring

Help Tab

• Quick reference for key expression patterns
• Getting started guide
• Usage examples

Key Expression Examples

• demo/** - Match all keys under the demo namespace
• sensor/*/temperature - Match temperature readings from any sensor
• device/1/status - Match the exact status key for device 1
• telemetry/**/cpu - Match CPU metrics at any depth under telemetry

Configuration

Connection Settings

• Locators: Specify one or more Zenoh endpoints (comma-separated)
• Mode: Choose between Client (connects to routers) or Peer (mesh participant)
• Advanced Config: Provide custom Zenoh configuration as JSON

Common Locator Formats

• tcp/localhost:7447 - Local TCP connection
• tcp/192.168.1.100:7447 - Remote TCP connection
• udp/224.0.0.224:7447 - UDP multicast
• quic/192.168.1.100:7447 - QUIC transport

Architecture

Zenoh Explorer is built with:

• egui/eframe: Native GUI framework for responsive, cross-platform interfaces
• Zenoh 1.0: Latest Zenoh protocol implementation with unstable features
• Tokio: Async runtime for handling network operations
• Chrono: Time handling for message timestamps
• Tracing: Structured logging for debugging

The application uses a dual-thread architecture:

• Main Thread:
  • GUI rendering and user interaction
  • Message history management
  • Worker health monitoring
• Worker Thread:
  • Async Zenoh operations
  • Subscription management
  • Network communication
• Communication:
  • std::sync::mpsc channels for thread-safe messaging
  • Command/Event pattern for clean separation
  • Health check ping/pong for liveness detection

Troubleshooting

Connection Issues

• Verify the Zenoh router is running and accessible
• Check firewall settings for the specified ports
• Try connecting in peer mode if client mode fails
• Ensure the locator format is correct

Peer Mode Configuration

• For multicast discovery: Leave locators empty in peer mode
• For specific endpoints: Provide tcp/ip:port format
• Peer mode enables automatic discovery of other peers via multicast
• If peer mode shows "Worker Unresponsive", check logs with RUST_LOG=zenoh_explorer=info

Query Functionality

• Important: Queries require queryable services to be running on the network
• If you receive "No queryables available" alerts, it means no services are responding to your query
• For passive data monitoring, use the Subscribe tab instead of Query
• Queryables are different from publishers - they actively respond to query requests

UI Issues

• The application automatically enables/disables buttons based on connection status
• Buttons are only active when connected to a Zenoh network

Performance Tips

• Use specific key expressions instead of broad wildcards when possible
• Clear message history periodically for long-running sessions
• Adjust performance limits using the sliders in the Messages tab:
  • Lower memory limit for resource-constrained systems
  • Higher rate limit for high-traffic monitoring
  • Balance message count vs memory usage
• Enable debug logging sparingly: RUST_LOG=zenoh_explorer=debug
• Use release builds for production: cargo build --release

Common Patterns

• Start with demo/** to test basic connectivity
• Use the publish tab to send test messages
• Monitor the messages tab to verify data flow
• Check the browse tab to understand network structure
• Use Subscribe for continuous data monitoring, Query for on-demand data requests

Contributing

This is a standalone Zenoh network explorer designed to be a generic debugging and monitoring tool. Contributions are welcome for:

• Additional transport protocol support
• Enhanced filtering and search capabilities
• Performance optimizations
• UI/UX improvements
• Documentation updates

License

Apache-2.0

Related Projects

• Zenoh: The core Zenoh protocol and implementations
• Zenoh Python: Python bindings for Zenoh
• Zenoh C: C/C++ bindings for Zenoh

Recent Updates

• Memory Management: Accurate memory tracking with configurable limits
• Rate Limiting: Token bucket algorithm to prevent message flooding
• Worker Health Monitoring: Visual indicators for system responsiveness
• Enhanced UI: Improved color schemes and button visibility
• Performance Controls: Real-time adjustment of limits via UI sliders
• Better Error Messages: More informative connection and query feedback