Introduction to Always On Tracing

Last published : Oct 14, 2026

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:
  1. Reproduce the issue — which may be intermittent or already resolved
  2. Start CDF tracing manually — requires admin access and coordination
  3. Collect logs — engineering-level tooling required to parse output
  4. 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