Introduction to Always On Tracing
What is AOT?
Always On Tracing (AOT) is a diagnostic framework built into Citrix Virtual Apps and Desktops. It continuously captures log data from infrastructure components — VDA, DDC, StoreFront™, NetScaler®, and others — and sends it to a centralized Log Server for indexed storage.
AOT is a curated subset of Citrix Diagnostic Facility (CDF) traces, extended with structured log data from other components. The key difference: it runs in the background automatically without requiring you to start a trace or reproduce the problem.
The Problem AOT Solves
Traditional Citrix troubleshooting requires:
- Reproduce the issue — which may be intermittent or already resolved
- Start CDF tracing manually — requires admin access and coordination
- Collect logs — engineering-level tooling required to parse output
- Escalate to Citrix Support — with incomplete or missing data
AOT eliminates every step in that chain. Logs are already captured. They’re already stored. They’re already searchable.
What AOT Gives You
- Faster MTTR — logs are available the moment an issue is reported, not after reproduction
- No manual intervention — tracing starts automatically when components are configured
- Self-service troubleshooting — IT admins can diagnose common issues without Citrix Support
- Readable logs — structured fields and keyword search, no parsing tools required
- Full context for escalations — when you do engage Support, you have everything
AOT vs. Traditional CDF Tracing
| Aspect | AOT | Traditional CDF Tracing |
|---|---|---|
| Activation | Automatic, continuous | Manual — must be started before the issue occurs |
| Issue reproduction | Not required | Required |
| Log readability | Structured, searchable fields | Raw ETW format, requires parsing tools |
| Diagnostic speed | Logs available immediately | Delayed by reproduction effort |
| Resource usage | Low overhead, optimized buffers | Moderate to high if misconfigured |
| Admin expertise needed | IT administrator | Engineering-level |
What AOT Captures
AOT collects logs from the following Citrix components:
- Delivery Controller (DDC)
- Virtual Delivery Agent (VDA) — Windows, Linux, Mac
- StoreFront
- Citrix Director / Monitor
- Federated Authentication Service (FAS)
- Provisioning Services (PVS)
- Session Recording
- Workspace Environment Management™ (WEM)
- User Profile Management (UPM)
- NetScaler Gateway
- License Server
- Cloud Connector
- Citrix Workspace App (CWA) — Windows, Mac, HTML5, ChromeOS, Android, iOS
Each log entry is tagged with structured fields: MachineName, MachineIP, Role, TimeStamp, Message, Level, Module, ProcessName, ProcessId, Thread, Cpu, SessionId, Class.
Who This Is For
- IT administrators managing Citrix environments who need to diagnose session failures, VDA registration errors, and infrastructure issues
- Citrix Support engineers who need full context from customer environments to resolve escalations quickly