Load-test OPC UA servers with configurable subscriptions and diagnostics
Console-based stress tester for validating OPC UA server performance under high subscription load before deployment.
What it is
A command-line OPC UA client that connects to any OPC UA server, browses the address space, subscribes to configurable numbers of variables, and measures throughput and latency in real time. Supports both None (plaintext) and encrypted security policies, with built-in diagnostics reporting (top N tags by update frequency), optional CSV per-node value logging for forensics, and automatic reconnect watchdog for stability under sustained load. Useful for validating the WizIIOT OPC UA server or third-party servers before deployment.
Key benefits
Multi-Client Load Generation
Launch multiple instances with distinct client IDs to simulate concurrent connections and measure server scalability limits (throughput saturation, subscription handling, message queue behavior).
Real-Time Diagnostics & CSV Logging
Built-in stats reporter shows top tags by update frequency every 5 minutes; optional async CSV logging captures every value change to disk without blocking the OPC UA receive thread, enabling post-test analysis of latency patterns and data loss.
Encoding Limit Handling
Automatically patches OPC UA stack limits (max message size, byte string length, array length) to prevent encoding errors on large Publish payloads and stabilize high-frequency subscriptions.
Automatic Reconnect & Stall Detection
Watchdog monitors for server state changes and data droughts; exponential backoff reconnection prevents test timeout during transient network issues without test abandonment.
Capabilities
- Configurable OPC UA subscriptions (sampling interval, publishing interval, notifications per publish) to stress-test under various load profiles
- Address-space browsing with namespace filtering and optional periodic rescan to discover dynamically created tags
- Multiple security modes: None (Java native) and encrypted/signed policies (requires Java compatibility layer)
- Per-client PKI certificate auto-generation and server certificate trust management
- Top-N tag frequency diagnostics and optional async CSV per-node data logging with configurable queue sizes and flush intervals
- Reconnect watchdog with configurable stall timeout and consecutive timeout burst detection for production-grade stability
- Heuristic tag filtering (well/meter/device path matching) for diagnostics and namespace-scoped subscriptions