User Input Delay - VM Test

One of the most difficult problems to diagnose by the administrators on virtual desktops is the poor performance of the applications installed. Traditionally, diagnosis was done by collecting CPU, memory, disk I/O and a few other metrics. The data collected from traditional metrics were not sufficient to figure out the root cause of poor performance of the applications on the virtual desktop since the variations measured by the metrics were large. Let's say, the user input (e.g. keyboard clicks and mouse clicks) sits in the input queue on the virtual desktop host for longer duration until the input is picked up for processing by an application’s message queue. In such a case, the User Input Delay starts increasing because the virtual desktop is under load, it means the slowness has been introduced on the virtual desktop (and is not due to the network). This could be a sign that user experience is degrading to the point where administrators might want to add more hosts or increase the VM instance size of your hosts. Therefore, it is necessary for administrators to measure the user input flows or rather user input delays while the applications are being accessed. This can be easily measured using the User Input Delay - VM test!

This test captures such user input delays at each Windows virtual desktop and reports the same to the administrators. With the help of this test, administrators can determine the maximum and average time taken by the applications to respond to the user input at the virtual desktop, and thus figure out if there is any time delay in responses from applications. In addition, these metrics help administrators to differentiate desktop-side issues from network issues.

Note:

This test will report measures only on virtual desktops running Windows 2010 or above.

Target of the test : A Windows virtual desktop on the cloud

Agent deploying the test : A remote agent

Outputs of the test : One set of results for the Windows virtual desktop on the cloud.

Configurable parameters for the test
Parameter Description

Test Period

How often should the test be executed.

Host

The nick name of the Cloud Desktops component for which this test is to be configured.

Port

Refers to the port at which the specified host listens to. By default, this is NULL.

Inside View Using

To obtain the 'inside view' of performance of the cloud-hosted Windows desktops - i.e., to measure the internal performance of the Windows virtual desktops - this test uses a light-weight eG VM Agent software deployed on each of the desktops. Accordingly, this parameter is by default set to eG VM Agent (Windows).

Report Powered OS

This flag is relevant only for those tests that are mapped to the Inside View of Desktops layer. If this flag is set to Yes (which is the default setting), then the 'inside view' tests will report measures for even those Windows virtual desktops that do not have any users logged in currently. Such desktops will be identified by their name and not by the username_on_virtualdesktopname. On the other hand, if this flag is set to No, then this test will not report measures for those Windows virtual desktops to which no users are logged in currently.  

Is Cloud VMs

Since this test runs for a 'Cloud Desktops' component, this flag is set to Yes by default.

DD Frequency

Refers to the frequency with which detailed diagnosis measures are to be generated for this test. The default is 2:1. This indicates that, by default, detailed measures will be generated every time this test runs, and also every time the test detects a problem. You can modify this frequency, if you so desire. Also, if you intend to disable the detailed diagnosis capability for this test, you can do so by specifying none against DD frequency.

Detailed Diagnosis

To make diagnosis more efficient and accurate, the eG Enterprise suite embeds an optional detailed diagnostic capability. With this capability, the eG agents can be configured to run detailed, more elaborate tests as and when specific problems are detected. To enable the detailed diagnosis capability of this test for a particular server, choose the On option. To disable the capability, click on the Off option.

The option to selectively enable/disable the detailed diagnosis capability will be available only if the following conditions are fulfilled:

  • The eG manager license should allow the detailed diagnosis capability
  • Both the normal and abnormal frequencies configured for the detailed diagnosis measures should not be 0.
Measurements made by the test
Measurement Description Measurement Unit Interpretation

Maximum input delay

Indicates the maximum amount of time lag detected between the user's input through any input device (e.g., mouse, keyboard) and the time at which the application responds to the input.

Seconds

Ideally, the values of these measures should be 0 or very low.

To know exactly which user/application experiences the maximum input lag, you can refer to the detailed diagnosis revealed by these measures.

Average input delay

Indicates the average amount of time lag detected between the user's input through any input device (e.g., mouse, keyboard) and the time at which the application detected the input.

Seconds