XenDesktop 故障分析和排查

1、Complex XenDesktop use cases; common mistakes; tools and techniques for resolution,Baptiste Duflos,Manager, Escalation Services,May 8th, 2012,Introduction and objectives,Tweet about this session with hashtag #SUM301and #CitrixSummit,Focusing on the major components of XenDesktop,4,WI,Controllers,VDA

2、s,AD,VM Host (XenServer, Hyper-V, VMware),Licensing,User,SQL Database,Deploying Controller Servers,5,All Controllers load balance session launch and VDA registrations Configuring Controllers in an N+1 configuration allows for resiliency in case of a failure All Controllers talk to the SQL database a

3、nd should deployed as close as possible,Controllers,Controller Server Scalability,6,XD4.x:,XD5.x:,Broker,Broker (ZDC),Broker,Hypervisor Pool,Controller,Controller,Controller(failed),WI,WI,Hypervisor Pool,Hypervisor Pool,Hypervisor Pool,Hypervisor Pool,Hypervisor Pool,Controllers Scalability and Best

4、 Practices,7,Can overwhelm the hosting infrastructure with power state requests during peak times when many users logon and off. You can throttle the amount of power commands sent per Controller with “MaximumTransitionRate” default is 20, do NOT increase it wont speed up power up times,Deploying SQL

5、 for XD Databases,8,XD 5 uses a single database with multiple schemas that map to XD services Stored procedures are leveraged to reduce load on database Database is critical to XD 5 all Controllers have heartbeat to database,SQL Databases,SQL Database Mirroring,9,Database failure = Controller Failur

6、e Only impacts new connections existing or disconnected sessions not affected Citrix recommends leveraging SQL Mirroring for fault tolerance,Principal database,Mirror database,Transaction log,Mirroring sends transaction log from Principal database to the redundant database,If the principal database

7、fails, user intervention is required to fail over the database Citrix recommends using synchronous database mirroring with witness,Witness Server,SQL Best Practices,10,SQL transaction log is critical to monitor Connection launches and idle desktops consume transaction log space Use a fixed-size tran

8、saction log auto-growth feature could impact response times Leverage SQL Alerts when log reaches thresholds (recommend 50%) Database failover tuning adjust Controller heartbeat interval Default heartbeat is 30secs and requires a SQL operation Controllers unregister workers that do not heartbeat for

9、over one minute Controlled by Regkey: HKLMSoftwareCitrixDesktopServerHeartbeatPeriodMs,Deploying Virtual Desktop Agents,11,VDA now uses “registry based” registration by default Verify ports are open and firewall configured Forward and Reverse DNS is required,Virtual Desktop Agents,VDA Scalability an

10、d best practice,12,Increase the Service timeouts if you expect periods with large amount of VMs rebooting increase to 3 mins recommended Optimize the logon process improves desktop performance Plan staged deployments and consider leveraging tools such like LoginVSI to perform scale and load testing

11、before adding large groups of users to environment,Key points to remember,13,Controllers are resilient and scale well keep deployments simple SQL server plays pivotal role in infrastructure protect it! Make your end users happy tune your VDAs for performance,Troubleshooting a session launch failure,

12、14,Users were reporting they got an error when trying to launch their desktops Admin noticed that intermittently VDAs would de-register at session launch,Case Study Walkthrough,Environment overview,15,XenDesktop deployment with: Web Interface 5.4 XD 5.6 SQL 2008 VMWare 5.0 Windows 2008 R2 Active Dir

13、ectory Virtual Desktop Agent OS Win7 32-bit Citrix Receiver 3.1,Web Interface 5.4,XD 5.6,SQL 2008,VMWare 5.0,Active Directory,VDAs,Receiver,What did failure look like?,16,17,User attempts to start the session,Initial Troubleshooting,18,How often does it happen? Any particular timeframe it happens? A

14、ny specific users or images it happens more frequently with? What changed? Any event viewer messages?,What changed?,19,WI,Controller #1,VDAs,Controller #2,VDAs register on Controller #1,Customer had single server deployment,Customer added second Controller for redundancy,Where do we start looking?,2

15、0,We found 4 interesting messages in Event Viewer:,Warning Event ID 2103: An unexpected exception occurred while the Citrix Broker Service processed an XML transaction. An incompatible client might be trying to access the XML service. Verify the compatibility of clients accessing the service. If thi

16、s problem persists, reinstall the Citrix XenDesktop Controller. Error details: Transaction: RequestAddress Exception Type: System.ServiceModel.Security.SecurityAccessDeniedException,Application Warning Event ID 1060: The Citrix Broker Service failed to apply settings on the virtual machine KB-WIN7-.

17、 Check that the virtual machine can be contacted from the Controller and that any firewall on the virtual machine allows connections from the Controller. See Citrix Knowledge Base article CTX126992. Error details: Exception Access is denied. of type System.ServiceModel.Security.SecurityAccessDeniedE

18、xception.,Warning Event ID 1039: The Citrix Broker Service failed to contact virtual machine KB-WIN7- (IP address ). Check that the virtual machine can be contacted from the Controller and that any firewall on the virtual machine allows connections from the Controller. See Citrix Knowledge Base arti

19、cle CTX126992. Error details: Exception Access is denied. of type System.ServiceModel.Security.SecurityAccessDeniedException.,Warning Event ID 1101: The Citrix Broker Service failed to broker a connection for user GETatladmin to resource KB-Win7-PW. The Citrix Broker Service cannot find any availabl

20、e virtual machines. Please add more virtual machines to the site. If the problem is due to existing virtual machines not becoming available, see Citrix Knowledge Base article CTX126992.,Troubleshooting Methodology verify environment,21,Check Firewall configuration Active Directory mis-configuration

21、Forward DNS and Reverse DNS Environmental checks: Check for time skew Default ports Port conflicts,Troubleshooting Methodology gathering data,22,Run Citrix Scout TaaS beta Enable logging on both Controllers Run a CDFTrace,Citrix Scout / XD Collector (CTX130147),23,Push button easy data collection sy

22、stem,Makes data collection and upload push button easy Integrates data collected by Scout with the Citrix Tools as a Service (TaaS) backend Simplifies data collection starting heartbeats,Under the hood - VDA Session Launch explained,29,VDA,Controller #1,Desktop Service,Controller #2,User,WI,VDA regi

23、sters to Controller #1,Worker flagged in DB as Ready,User launches session,WI Sends launch request to XML Broker,XML broker queries DB for a ready worker,XML sends PrepareSession ticket to VDA,XML Broker unregisters worker,ListOfDDCs=Controller #1,VDA checks ListOfDDCs to authorize PrepareSession,Co

24、ntroller #2 is not in ListOfDDCs, VDA invalidates session launch request,XML Returns Error to WI,WI Error returned to user,Broker Service,XML Broker,Worker is placed in SinBin,Root Cause analysis,30,The customer added a second Controller to handle XML requests for redundancy As soon as the new Contr

25、oller was added to the WI XML failover list it was available to broker session launches by design Since the new Controller was not added as an authorized trusted agent XenDesktop rejects the session logons Workstation agent de-registers temporarily and then attempts to re-register,Resolution,31,DDCs

26、 that handle authentication must be authorized agents and added to “ListOfDDCs” registry value CTX132536 outlines the registry key and how to define broker groups Adding DDCs to WI XML failover list enables the ability for DDCs to handle session logons,Resources discussed,Optimal deployment recommen

27、dations,33,CTX124087 - XenDesktop Modular Reference Architecture CTX127939 - XenDesktop 5 Database Sizing and Mirroring Best Practices CTX123244 - High Availability for Desktop Virtualization - Reference Architecture CTX120760 - XenDesktop - Design Handbook CTX128700 - XenDesktop Planning Guide - XenDesktop Scalability Whitepaper - Benchmarking Citrix XenDesktop usin