How to Troubleshoot the XenDesktop VDAKaren SciberrasEscalation Engineer

• How to troubleshoot effectively

• XenDesktop Architecture

• Troubleshooting VDA Connectivity

• Tools

• Case Studies

Agenda

• Narrowing down the faulting component

• Collect further information for rapid debugging

• Avoids different root causes treated as same issue

• Avoids issue being handed around the teams

• Helps resolving the root cause instead of the symptoms

Effective Troubleshooting

• Understand the architecture

• Learn the shortcuts and tips

• Preserve the VDA state

How to effectively troubleshoot issues?

XenDesktop Broker System Architecture

WIDDC Servers

VDAs(VMs, Blade PCs)

AD

ICA

Web Service

Web

Ser

vice

LDAP

VM Host(XenServer, Hyper-V, VMware)

LDAP

Licensing

User

• Desktop Delivery Controller (Broker) Farm

• Uses core XenApp technology

• IMA, licensing, Web Interface, XML

• Delivers and controls access to virtual desktops

• VDA technology independent

• User authentication / single sign on

• VM power management

• ICA policy decision

DDCDDC

XenDesktop Architecture

Workstation(VM or blade PC)

Workstation(VM or blade PC)

Workstation(VM or blade PC)

Workstation(VM or blade PC)

VDAVDA

DriversDrivers

Citrix ICA Svc

Citrix ICA Svc

Citrix Desktop Svc

Citrix Desktop Svc

“XTE” Svc“XTE” Svc

IMAProxy IMAProxy Pool ManagerPool Manager

Controller SvcController Svc

IMAIMA

WCFXML SvcXML Svc

VDAVDA

VDA Registration

VDA DDC

AD

WCF

DDC ServerDDC Server

Controller Service

Controller Service

IMAIMA Service starts, looks up farm OU Service queries DC for all SCPs in that OU

DDC service receives connection OS retrieves Kerberos ticket for DDC and initiates a connection through WCF

Service looks up VDA computer account

Service selects one DDC at random, looks up DDC computer account

DDC checks that computer account (SID) is in published group in IMA Service initiates WCF connection to VDA and sends XML blob

Call succeeds, VDA marked registered

Service validates that caller is member of “Controllers” group, and sets configuration from XML Blob

LDAP

Desktop ServiceDesktop Service

XML Blob

Troubleshooting VDA Connectivity

Desktop SvcICA Svc

(PicaSvc)

ICA Stack

XenDesktop Brokering

Clicks on desktop group

Web Interface

Request for brokering

DDC

VDA

StartListening()

(Listening)

StartListening()

Launch.icaEnd user

Desktop Svc

ICA Svc (PicaSvc)

ICA Stack

XenDesktop ICA ConnectionVDAEnd user

TcpIp.sys

CGPService

Authentication

PicaDisplayMgr

Thinwire

Lock()

ConnectionAccept()

SetRemotePushPrelogonData()

To DDC: Exchange Ticket

Logon

ICA Connection

• Orchestrates ICA connection, components, and features

• Event driven (Connect, Disconnect, Logon, Logoff, etc.)

• State machine per session to handle events

ICA Service (PicaSvc)

• Most important log file in the VDA

• Allows us to narrow down the faulting component

• How to configure: KB Article CTX118837

• Use trace level 5

• Level 9 is excessive for initial troubleshooting

ICA Service Log File

• Thread ID

• Entry/Exits

• State Machines Traces

• Session IDs

• PicaSvc log file common pitfalls• Search terms that need to be avoided. (error, exception, broken)• Instead search for “fail”

• Filtering the trace messages

Anatomy of the PicaSvc log file

Troubleshooting Tools

• XDPing

• Clear-text CDF Tracing•Log files: Workstation Agent log, PortICA log

• CDF Control

• CDF Marker• PerfMon, PsExec,

Troubleshooting Tools

• RPC_S_INVALID_BINDING is not a real error

• “ConnectAccept failed” is an ICA stack problem

• Next step: CDF• MF_Driver_Wdica• Portica_Driver_Picadd• Portica_Driver_Td

• Provide the CDF log with the PicaSvc log for further analysis

Case 1

• First few SwitchDisplayToLocal failure is not fatal. State machine shows success.

• No issues found on the VDA

• Next step:•Collect traces from DDC and Workstation Agent•Collect network trace from client to verify if ICA Connection attempt

Case 2

• Enable Clear-Text CDF tracing

• Read through Log file using Session Parser•Historical usage•Detailed Session data•Connection tracking per user or per workstation

Desktop Delivery Controller Log

• XDPing – CTX123278

• DDC and WorkStation Agent Logs – CTX117453

• ICA Service (PortICA Log) – CTX118837

• CDF Marker – CTX124577

• CDF Marker and PSExec – CTX125345

• Session Parser – CTX124012

KB Articles

• CDFMarker may not send a CDF Trace Message from the Command Line - CTX125346

• How to Use CDFMarker and PerfMon when a Process Intermittently Spikes - CTX125347

• How to Use CDFMarker to Add CDF Tracing to Batch Files and Scripts - CTX125486

• How to Use CDFMarker to Mark an Intermittent End User Issue in a CDF Trace - CTX125503

• How to Use CDFMarker and PerfMon to Identify Large LHC Writes - CTX125634

• How to Mark High Bandwidth in a CDF Trace using CDFMarker and PerfMon - CTX125724

• How to Mark a Service Termination in a CDF Trace using CDFMarker - CTX125736

• How to Mark when a Process Crash Occurs in a CDF Trace using CDFMarker - CTX125750

CDFMarker

Importance of troubleshooting effectively

XenDesktop Architecture and Logon Process

XdPing

Log file on the DDC Controller Svc and VDA Desktop Svc

Log file on the ICA Service

Remote tracing – CDF Control, CDF Marker and PSExec

Session parser to read DDC log file

Takeaways

Before you leave…

• Recommended related breakout sessions: • Debugging XenApp and XenDesktop Issues by Lalit Kaushal.

• Session surveys are available online at www.citrixsummit.com starting Thursday, 7 October• Provide your feedback and pick up a complimentary gift card at the registration desk

• Download presentations starting Friday, 15 October, from your My Organiser Tool located in your My Synergy Microsite event account