Desktop’s HDX Channel Test

As already mentioned, the key factors influencing user experience in a virtual desktop infrastructure are the latencies experienced by the user while connecting to the desktop via ICA and the bandwidth used when a user interacts with a virtual desktop. High latency and excessive bandwidth consumption can often slowdown access to desktops, thereby significantly delaying subsequent user operations. Hence, monitoring the latency and bandwidth usage of the ICA communication channel between the user terminal and the virtual desktops is essential.

The Desktop's HDX Channel test auto-discovers the virtual desktops on the XenServer host and the users who are currently connected to each desktop.  For each such user, the test monitors the communication between a user and the virtual desktop, and reports the following:

  • The latency experienced by each user session;
  • The bandwidth used by the incoming and outgoing data/audio/multimedia traffic transacted by the ICA communication channel between each user and virtual desktop;

Using this test, an administrator can identify user sessions that are being impacted by high latency and abnormal bandwidth usage. In addition, the test also reveals the type of traffic that is causing excessive bandwidth usage, thereby providing pointers to how the client configuration can be fine-tuned in order to reduce bandwidth consumption and improve performance.

This test is disabled by default. To enable the test, go to the enable / disable tests page using the menu sequence: Agents -> Tests -> Enable/Disable, pick Citrix XenServer - VDI as the Component type, set Performance as the Test type, choose this test from the disabled tests list, and click on the >> button to move the test to the enableD tests list.

Note:

This test will report metrics only if the following conditions are fulfilled:

  • The test is applicable to Windows VMs only.
  • The VMs being monitored should be managed by XenDesktop Broker.
  • The Virtual Desktop Agent software should have been installed on the VMs.
  • The ICA Session performance object should be enabled on the VMs.

Target of the test : A Citrix XenServer

Agent deploying the test : An internal/remote agent

Outputs of the test : One set of results for every user who is connected to a virtual desktop via ICA

Configurable parameters for the test

  1. Test period - How often should the test be executed
  2. Host - The host for which the test is to be configured.
  3. port - The port at which the specified host listens. By default, this is NULL.
  4. XEN user - To enable the eG agent to connect to the XenServer API for collecting statistics of interest, this test should login to the XenServer as a root user. Provide the name of the root user in the XEN USER text box. Root user privileges are mandatory when monitoring a XenServer 5.5 (or below). However, if you are monitoring XenServer 5.6 (or above) and you prefer not to expose the credentials of the root user, then, you have the option of configuring a user with pool-admin privileges as the xen user. If you do not want to expose the credentials of a root/pool-admin user, then you can configure the tests with the credentials of a xen user with Read-only privileges to the XenServer. However, if this is done, then the Xen Uptime test will not run, and the Xen CPU and Xen Memory tests will not be able to report metrics for the control domain descriptor. To avoid such an outcome, do the following before attempting to configure the eG tests with a xen user who has Read-only privileges to the XenServer:

    • Modify the target XenServer’s configuration in the eG Enterprise system. For this, follow the Infrastructure -> Components -> Add/Modify menu sequence, pick Citrix XenServer as the Component type, and click the Modify button corresponding to the target XenServer.
    • In the modify component details page that then appears, make sure that the os is set to Xen and the Mode is set to ssh.
    • Then, in the same page, proceed to provide the User and Password of a user who has the right to connect to the XenServer console via SSH.
    • Then, click the Update button to save the changes.

    Once this is done, you can configure the eG tests with the credentials of a xen user with Read-only privileges.

  5. xen password - The password of the specified xen user needs to be mentioned here.
  6. confirm password - Confirm the xen password by retyping it here.
  7. ssl - By default, the Xen Server is not SSL-enabled. This indicates that by default, the eG agent communicates with the XenServer using HTTP. Accordingly, the ssl flag is set to No by default. If you configure the XenServer to use SSL, then make sure that the SSL flag is set to Yes, so that the eG agent communicates with the XenServer using HTTPS. Note that a default SSL certificate comes bundled with every XenServer installation. If you want the eG agent to use this default certificate for communicating with an SSL-enabled XenServer, then no additional configuration is required. However, if you do not want to use the default certificate, then you can generate a self-signed certificate for use by the XenServer. In such a case, you need to explicitly follow the broad steps given below to enable the eG agent to communicate with the XenServer via HTTPS:

    • Obtain the server-certificate for the XenServer
    • Import the server-certificate into the local certificate store of the eG agent

    For a detailed discussion on each of these steps, refer to the Troubleshooting section of this document.

  8. INSIDE VIEW USING - By default, this test communicates with every VM remotely and extracts “inside view” metrics. Therefore, by default, the INSIDE VIEW USING flag is set to Remote connection to VM (Windows).

    Typically, to establish this remote connection with Windows VMs in particular, eG Enterprise requires that the eG agent be configured with domain administrator privileges. In high-security environments, where the IT staff might have reservations about exposing the credentials of their domain administrators, this approach to extracting “inside view” metrics might not be preferred. In such environments therefore, eG Enterprise provides administrators the option to deploy a piece of software called the eG VM Agent on every Windows VM; this VM agent allows the eG agent to collect “inside view” metrics from the Windows VMs without domain administrator rights. Refer to Configuring Windows Virtual Machines to Support the eG Agent’s Inside View Using the eG VM Agent for more details on the eG VM Agent. To ensure that the “inside view” of Windows VMs is obtained using the eG VM Agent, set the INSIDE VIEW USING flag to eG VM Agent (Windows). Once this is done, you can set the DOMAIN, ADMIN USER, and ADMIN PASSWORD parameters to none.

  9. DOMAIN, ADMIN USER, ADMIN PASSWORD, and CONFIRM PASSWORD - By default, this test connects to each virtual guest remotely and attempts to collect “inside view” metrics. In order to obtain a remote connection, the test must be configured with user privileges that allow remote communication with the virtual guests. The first step towards this is to specify the DOMAIN within which the virtual guests reside. The ADMIN USER and ADMIN PASSWORD will change according to the DOMAIN specification. Discussed below are the different values that the DOMAIN parameter can take, and how they impact the ADMIN USER and ADMIN PASSWORD specifications:

    • If the VMs belong to a single domain : If the guests belong to a specific domain, then specify the name of that domain against the DOMAIN parameter. In this case, any administrative user in that domain will have remote access to all the virtual guests. Therefore, an administrator account in the given domain can be provided in the ADMIN USER field and the corresponding password in the ADMIN PASSWORD field. Confirm the password by retyping it in the CONFIRM PASSWORD text box.
    • If the guests do not belong to any domain (as in the case of Linux guests) : In this case, specify "none" in the DOMAIN field, and specify a local administrator account name in the ADMIN USER below.

      Prior to this, you need to ensure that the same local administrator account is available or is explicitly created on each of the virtual machines to be monitored. Then, proceed to provide the password of the ADMIN USER against ADMIN PASSWORD, and confirm the password by retyping it in the CONFIRM PASSWORD text box.

      If key-based authentication is implemented between the eG agent and the SSH daemon of a Linux guest, then, in the ADMIN USER text box, enter the name of the user whose <USER_HOME_DIR> (on that Linux guest) contains a .ssh directory with the public key file named authorized_keys. The ADMIN PASSWORD in this case will be the passphrase of the public key; the default public key file that is bundled with the eG agent takes the password eginnovations. Specify this as the ADMIN PASSWORD if you are using the default private/public key pair that is bundled with the eG agent to implement key-based authentication. On the other hand, if you are generating a new public/private key pair for this purpose, then use the passphrase that you provide while generating the pair. For the detailed procedure on Implementing Key-based Authentication refer to Troubleshooting the Failure of the eG Remote Agent to Connect to or Report Measures for Linux Guests.

    • If the guests belong to different domains - In this case, you might want to provide multiple domain names. If this is done, then, to access the guests in every configured domain, the test should be configured with the required user privileges; this implies that along with multiple DOMAIN names, multiple ADMIN USER names and ADMIN PASSWORDs would also have to be provided. To help administrators provide these user details quickly and easily, the eG administrative interface embeds a special configuration page.

      To access this page, simply click on the Click here hyperlink that appears just above the parameters of this test in the test configuration page. To know how to use the special page, refer to Configuring Users for VM Monitoring.

    • If the INSIDE VIEW USING flag is set to ‘eG VM Agent (Windows)’ - In this case, the inside view can be obtained without domain administrator privileges. Therefore, set the domain, admin user, and admin password parameters to none.

  10. IGNORE VMS INSIDE VIEW - Administrators of some high security XenServer environments might not have permissions to internally monitor one/more VMs. The eG agent can be configured to not obtain the 'inside view' of such ‘inaccessible’ VMs using the IGNORE VMS INSIDE VIEW parameter. Against this parameter, you can provide a comma-separated list of VM names, or VM name patterns, for which the inside view need not be obtained. For instance, your IGNORE VMS INSIDE VIEW specification can be: *xp,*lin*,win*,vista. Here, the * (asterisk) is used to denote leading and trailing spaces (as the case may be). By default, this parameter is set to none indicating that the eG agent obtains the inside view of all VMs on a XenServer host by default.

    Note:

    While performing VM discovery, the eG agent will not discover the operating system of the VMs configured in the IGNORE VMS INSIDE VIEW text box.

  11. EXCLUDE VMS - Administrators of some virtualized environments may not want to monitor some of their less-critical VMs - for instance, VM templates - both from 'outside' and from 'inside'. The eG agent in this case can be configured to completely exclude such VMs from its monitoring purview. To achieve this, provide a comma-separated list of VMs to be excluded from monitoring in the EXCLUDE VMS text box. Instead of VMs, VM name patterns can also be provided here in a comma-separated list. For example, your EXCLUDE VMS specification can be: *xp,*lin*,win*,vista. Here, the * (asterisk) is used to denote leading and trailing spaces (as the case may be). By default, this parameter is set to none indicating that the eG agent obtains the inside and outside views of all VMs on a virtual host by default. By providing a comma-separated list of VMs/VM name patterns in the EXCLUDE VMS text box, you can make sure the eG agent stops collecting 'inside' and 'outside' view metrics for a configured set of VMs.
  12. IGNORE WINNT - By default, the eG agent does not support the inside view for VMs executing on Windows NT operating systems. Accordingly, the IGNORE WINNT flag is set to Yes by default.
  13. webport - By default, in most virtualized environments, the XenServer listens on port 80 (if not SSL-enabled) or on port 443 (if SSL-enabled). This implies that while monitoring an SSL-enabled XenServer, the eG agent, by default, connects to port 443 of the server to pull out metrics, and while monitoring a non-SSL-enabled XenServer, the eG agent connects to port 80. Accordingly, the webport parameter is set to 80 or 443 depending upon the status of the ssl flag.  In some environments however, the default ports 80 or 443 might not apply. In such a case, against the webport parameter, you can specify the exact port at which the XenServer in your environment listens so that the eG agent communicates with that port.
  14. REPORT BY USER - While monitoring a Citrix XenServer, the REPORT BY USER flag is set to No by default, indicating that by default, the guest operating systems on the XenServer are identified using the hostname specified in the operating system. On the other hand, while monitoring a Citrix XenServer - VDI, this flag is set to Yes by default; this implies that in case of the XenServer VDI model, by default, the desktops will be identified using the login of the user who is accessing them. In other words, in VDI environments, this test will, by default, report measures for every username_on_virtualmachinename.

  15. REPORT POWERED OS - This flag becomes relevant only if the report by user flag is set to ‘Yes’.

    If the report powered os flag is set to Yes (which is the default setting), then this test will report measures for even those VMs that do not have any users logged in currently. Such guests will be identified by their virtualmachine name and not by the username_on_virtualmachinename. On the other hand, if the report powered os flag is set to No, then this test will not report measures for those VMs to which no users are logged in currently.  

 

Measurements of the test

Measurement Description Measurement Unit Interpretation

Session average latency:

Indicates the average client latency over the lifetime of this session.

Secs

Comparing the value of this measure across users will enable administrators to quickly and accurately identify users who are experiencing higher latency when connecting to a virtual desktop.

Session deviation latency:

Indicates the difference between the minimum and maximum measured latency values for this session.

Secs

 

Audio bandwidth input:

Indicates the bandwidth used while transmitting sound/audio to this user.

Kbps

Comparing these values across users will reveal which user is sending/receiving bandwidth-intensive sound/audio files over the ICA channel.

To minimize bandwidth consumption, you may want to consider disabling client audio mapping.

Audio bandwidth output:

Indicates the bandwidth used while receiving sound/audio from this user.

Kbps

COM bandwidth input:

Indicates the bandwidth used when sending data to this user’s COM port.

 

Kbps

Comparing these values across users will reveal which user’s COM port is sending/receiving bandwidth-intensive data over the ICA channel.

COM bandwidth ouput:

Indicates the bandwidth used when receiving data from this user’s COM port.

Kbps

Drive bandwidth input:

Indicates the bandwidth used when this user performs file operations on the mapped drive on the virtual desktop.

Kbps

Comparing the values of these measures across users will reveal which user is performing bandwidth-intensive file operations over the ICA channel.

If bandwidth consumption is too high, you may want to consider disabling client drive mapping on the client device. Client drive mapping allows users logged on to a virtual desktop from a client device to access their local drives transparently from the ICA session. Alternatively, you can conserve bandwidth by even refraining from accessing large files with client drive mapping over the ICA connection.

Drive bandwidth output:

Indicates the bandwidth used when the virtual desktop performs file operations on the client’s drive.

Kbps

Printer bandwidth input:

Indicates the bandwidth used when this user prints to a desktop printer over the ICA channel.

Kbps

Comparing the values of these measures across users will reveal which user is issuing bandwidth-intensive print commands over the ICA channel.

If bandwidth consumption is too high, you may want to consider disabling printing. Alternatively, you can avoid printing large documents over the ICA connection.

Printer bandwidth output:

Indicates the bandwidth used when the desktop responds to print jobs issued by this user. 

Kbps

Session bandwidth input:

Indicates the bandwidth used from this user to the virtual desktop for a session

Kbps

Comparing the values of these measures across users will reveal which user and which virtual desktop is performing bandwidth-intensive operatons for a session.

Session bandwidth output:

Indicates the bandwidth used from the virtual desktop to this user for a session.

Kbps

Session compression input:

Indicates the compression ratio used from this user to the virtual desktop for a session.

Number

Compression reduces the size of the data that is transacted over the ICA channel.

Comparing the values of these measures across users will reveal which client has been configured with a very low and a very high compression ratio.

In the event of high bandwidth usage over an ICA channel, you can set a higher compression ratio for the corresponding client and thus reduce bandwidth consumption.

Session compression output:

Indicates the compression ratio used from the virtual desktop to this user for a session.

Number

Speed screen data channel bandwidth input:

Indicates the bandwidth used from this user to the virtual desktop for data channel traffic.

Kbps

Comparing the values of these measures across users will reveal which user has been transmitting/receiving bandwidth-intensive data channel traffic.

 

Speed screen data channel bandwidth output:

Indicates the bandwidth used from virtual desktop to this user for data channel traffic.

Kbps

Speed screen multimedia acceleration bandwidth input:

Indicates the bandwidth used from this user to virtual desktop for multimedia traffic.

Kbps

Comparing the values of these measures across users will reveal which user has been transmitting/receiving bandwidth-intensive multimedia traffic.

 

 

Speed screen multimedia acceleration bandwidth output:

Indicates the bandwidth used from the virtual desktop to this user for multimedia traffic

Kbps

HDX media stream for flash data bandwidth input:

Indicates the bandwidth used from this user to virtual desktop for flash data traffic.

Kbps

Comparing the values of these measures across users will reveal which user has been transmitting/receiving bandwidth-intensive flash data.

 

 

HDX media stream for flash data bandwidth output:

Indicates the bandwidth used from the virtual desktop to this user for flash data traffic

Kbps

 

USB bandwidth input:

Indicates the bandwidth used from this user to the virtual desktop for the USB port-related traffic.

Kbps

Comparing the values of these measures across users will reveal which user has been transmitting/receiving bandwidth-intensive USB traffic.

 

USB bandwidth output:

Indicates the bandwidth used from the virtual desktop to this user for the USB port-related traffic.

Kbps

Last recorded latency:

Indicates the last recorded latency of this user session.

Secs

Comparing the value of this measure across user sessions will enable administrators to quickly and accurately identify users who experienced high latencies recently.

Input line speed:

Indicates the average line speed of all the sessions of this user to the desktop.

KB/Sec

 

Output line speed:

Indicates the average line speed of all sessions from the desktop to this user.

KB/Sec

 

Bandwidth usage:

Indicates the percentage HDX bandwidth consumption of this user.

Percent

Compare the value of this measure across users to know which user is consuming the maximum HDX bandwidth.

Resource shares:

Indicates the total number of resource shares used by this user.

Number

By comparing the value of this measure across users, you can identify the user who is hogging the resources.

Frame rate:

Indicates the rate at which frames are processed during this user session.

 

Frames/Sec

FPS is how fast your graphics card can output individual frames each second. It is the most time-tested and ideal measure of performance of a GPU. Higher the value of this measure, healthier is the GPU.

Framehawk frame rate:

Indicates the rate at which frames are processed by the Framehawk virtual channel, if it is enabled for this user session.

Frames/Sec

The Framehawk virtual channel optimizes the delivery of virtual desktops and applications to users on broadband wireless connections, when high packet loss or congestion occurs.

Note:

This measure will report the value 0 if Framehawk is not enabled for a user or if the device from which the user is accessing the application does not support Framehawk.

Framehawk network bandwidth:

Indicates the bandwidth consumption of this user session when the Framehawk virtual delivery channel is used.

Kbps

This measure will report the value 0 if Framehawk is not enabled for a user or if the device from which the user is accessing the application does not support Framehawk.

Framehawk latency:

Indicates the latency experienced by this user session when the Framehawk virtual delivery channel is used.

Secs

This measure will report the value 0 if Framehawk is not enabled for a user or if the device from which the user is accessing the application does not support Framehawk.

Framehawk network loss:

Indicates the percentage of packet loss experienced by this user session when the Framehawk virtual delivery channel is used.

Percent

This measure will report the value 0 if Framehawk is not enabled for a user or if the device from which the user is accessing the application does not support Framehawk.

User's connection quality indicator:

Indicates the connectivity of this user with the Citrix environment.

 

The values that this measure can report and their corresponding numeric values are discussed in the table above:

Measure Value Numeric Value
Poor connection 1
Weak connection 2

Strong connection

3

None

4

Note:

By default, this measure reports the Measure Values listed in the table above. In the graph of this measure however, the value of this measure is represented using their numeric equivalents only.

By default, Citrix recommends a standard computation of user’s connection quality indicator as mentioned in the table below:

Connection Quality Indicator How is the Connection Quality Indicator calculated?

Weak

Reported when

  • Bandwidth > 1MBPs
  • Latency <= 150ms
  • ICA RTT <= 180ms

Strong

Reported when

  • Bandwidth > 8 MBPs
  • Latency <= 150ms
  • ICA RTT <= 180ms

None

Reported when

  • Bandwidth <= 0 MBPs
  • Latency < 0
  • ICA RTT < 0

Poor

Reported when any condition other than the above is noticed.