AVD Session Hosts By Host Pools

The AVD connection broker brokers desktop connections between the user and session hosts residing in a host pool. If users are unable to connect to a session host or if they often complain of annoying session disconnects, then the reliability of the AVD service will be questioned. To avoid this, administrators should continuously track the status of session hosts and user sessions of each host pool managed by the broker, identify hosts/sessions in an abnormal state, diagnose the reason for the abnormality, and fix it. This can be done using the AVD Sessions Hosts by Host Pools test.

This test checks the availability of every host pool, and alerts administrators if any host pool is unavailable. For available host pools, the test further tracks the status of the hosts in the pool, and notifies administrators if any host is in an abnormal state. The abnormality can imply that a host is unavailable / powered off / disconnected, or that an upgrade failure has occurred on the host. Additionally, the test also reveals if any host in a pool is idle - idle hosts are resource drainers, and hence, their numbers should be kept at a minimum. The test also monitors user sessions to the hosts in every pool, and reports the status of these sessions. Host pools with sessions in a disconnected or an 'Unknown' state are thus pinpointed. If any session is waiting too long to connect to a host, or there are one/more sessions that have abruptly logged off, then administrators are informed of the same, This way, the test draws administrator attention to host pools with 'unhealthy' hosts and sessions. Detailed diagnosis of the test, if enabled, lead administrators to the exact hosts in the pool that are in an abnormal state. Using the detailed metrics, you can also identify the hosts in the pool with sessions in an unhealthy state.

Note:

Typically, to consolidate log entries, correlate log data, and perform complex analysis, a host pool's logs are often sent to one/more Log Analytics Workspaces. This test reports valid metrics by reading data from these Log Analytics Workspaces only. If the host pool's logs are not sent to any Log Analytics Workspace, then this test will only report the value 0 for most of its measures. To avoid this, before configuring this test, make sure that the host pool's logs are configured to be sent to at least one Log Analytics Workspace. Follow the steps discussed in Configuring the Host Pool Logs to be Sent to a Log Analytics Workspace to achieve this.

Target of the Test: A Microsoft AVD Broker

Agent deploying the test: A remote agent

Output of the test: One set of results for each AVD host pool managed by the target AVD broker, in each resource group of the configured subscription

Configurable parameters for the test
Parameters	Description
Test Period	How often should the test be executed.
Host	The host for which the test is to be configured.
Subscription ID	Specify the GUID which uniquely identifies the Microsoft Azure Subscription to be monitored. To know the ID that maps to the target subscription, do the following: Login to the Microsoft Azure Portal. When the portal opens, click on the Subscriptions option (as indicated by Figure 1). Figure 1 : Clicking on the Subscriptions option Figure 2 that appears next will list all the subscriptions that have been configured for the target Azure AD tenant. Locate the subscription that is being monitored in the list, and check the value displayed for that subscription in the Subscription ID column. Figure 2 : Determining the Subscription ID Copy the Subscription ID in Figure 2 to the text box corresponding to the SUBSCRIPTION ID parameter in the test configuration page.
Tenant ID	Specify the Directory ID of the Azure AD tenant to which the target subscription belongs. To know how to determine the Directory ID, refer to Configuring the eG Agent to Monitor a Microsoft AVD Broker Using Azure ARM REST API
Client ID and Client Password	To collect the required metrics, the eG agent requires an Access token in the form of an Application ID and the client secret value. If a Microsoft Azure Subscription component or a Microsoft Azure Active Directory component is already being monitored, then an Application would have already been created for monitoring purposes. The Application ID and Client Secret of such an application can be specified here. However, if no such application exists, then you will have to create one for monitoring the AVD broker. To know how to create such an application and determine its Application ID and Client Secret, refer to Configuring the eG Agent to Monitor a Microsoft AVD Broker Using Azure ARM REST API. Specify the Application ID of the created Application in the Client ID text box and the client secret value in the Client Password text box.
Proxy Host	In some environments, all communication with the Azure cloud be routed through a proxy server. In such environments, you should make sure that the eG agent connects to the cloud via the proxy server and collects metrics. To enable metrics collection via a proxy, specify the IP address of the proxy server and the port at which the server listens against the Proxy Host and Proxy Port parameters. By default, these parameters are set to none, indicating that the eG agent is not configured to communicate via a proxy, by default.
Proxy Username, Proxy Password and Confirm Password	If the proxy server requires authentication, then, specify a valid proxy user name and password in the Proxy Username and Proxy Password parameters, respectively. Then, confirm the password by retyping it in the Confirm Password text box.
Log Analytics Workspace Name	Typically, to consolidate log entries, correlate log data, and perform complex analysis, a host pool's logs are often sent to one/more Log Analytics Workspaces. By default, the Log Analytics Workspace Name parameter is set to All. This indicates that the test reads log data from all Log Analytics Workspaces configured for the target subscription, by default. However, if you want the test to use only those Log Analytics Workspaces to which a host pool's logs are sent, then provide the names of these workspaces here as a comma-separated list. To determine the names of the workspaces, do the following: Login to the Microsoft Azure Portal, and click on Host Pools to view the configured host pools. Select any of the host pools displayed therein by clicking on it. Next, keep scrolling down the left panel of the page that then appears, until the Diagnostic Settings option (under Monitoring) become visible. Click on Diagnostic Settings to proceed. The diagnostic settings that pre-exist (if any) for the chosen host pool will then appear. If any of the existing diagnostic settings have already been configured with Log Analytics Workspaces, then the Log Analytics workspace column of that list will display these workspace names. You can configure the LOG ANALYTICS WORKSPACE NAME parameter of this test with any of these workspace names. If required, you can even configure this parameter with two/more workspaces displayed here, as a comma-separated list However, If the Log Analytics workspace column is blank for all the existing diagnostic settings, it is a clear indication that the host pool's logs are yet to be configured to be sent to any Log Analytics Workspace. In this case therefore, you should create a new diagnostic setting for the target host pool where a Log Analytics Workspace is configured as the destination for the logs. To achieve this, follow the procedure detailed in Configuring the Host Pool Logs to be Sent to a Log Analytics Workspace.
Active Session DD	By default, this test does not report detailed diagnostics for the Active sessions measure. Accordingly, this parameter is set to No by default. Typically, in large AVD roll-outs, this measure can report numerous records as part of detailed diagnostics. In such environments therefore, the detailed statistics for this measure can consume excessive space in the eG database. This default setting conserves valuable database space by ensuring that the test does not collect detailed metrics for the Active sessionsmeasure. However, If you have a well-sized and well-tuned eG database, you can configure the test to capture detailed metrics for this measure. To achieve this, set this flag to Yes.
Disconnected Session DD	By default, this test does not report detailed diagnostics for the Disconnected sessions measure. Accordingly, this parameter is set to No by default. However, if needed, you can configure the test to capture detailed metrics for this measure. To achieve this, set this flag to Yes.
Unknown Session DD	By default, this test does not report detailed diagnostics for the Unknown sessions measure. Accordingly, this parameter is set to No by default. However, if needed, you can configure the test to capture detailed metrics for this measure. To achieve this, set this flag to Yes.
Logoff Session DD	By default, this test does not report detailed diagnostics for the Logoff sessions measure. Accordingly, this parameter is set to No by default. However, if needed, you can configure the test to capture detailed metrics for this measure. To achieve this, set this flag to Yes.
Pending Session DD	By default, this test does not report detailed diagnostics for the Pending sessions measure. Accordingly, this parameter is set to No by default. However, if needed, you can configure the test to capture detailed metrics for this measure. To achieve this, set this flag to Yes.
Disk Mount Session DD	By default, this test does not report detailed diagnostics for the User profile disk mount sessions measure. Accordingly, this parameter is set to No by default. However, if needed, you can configure the test to capture detailed metrics for this measure. To achieve this, set this flag to Yes.
DD Frequency	Refers to the frequency with which detailed diagnosis measures are to be generated for this test. The default is 1:1. 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, eG Enterprise 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.

Measures made by the test:

Measurement

Description

Measurement Unit

Interpretation

Status

Indicates whether/not this host pool is available currently.

The values that this measure reports and their corresponding numeric values are listed in the table below:

Measure Value	Numeric Value
Unavailable	0
Available	1

Note:

By default, this measure reports the Measure Values listed in the table above to indicate the current status of the host pool. In the graph of this measure however, the same is represented using the numeric equivalents only.

Use the detailed diagnosis of this measure to view the friendly name of the host pool, host pool type, load balancer type, and maximum number of sessions allowed on the host pool.

Total session hosts

Indicates the total number of session hosts in this host pool.

Number

Use the detailed diagnosis of this measure to know which session hosts are in the host pool, where they are located, and what the current status of each session host is. Unavailable session hosts in the pool can be identified in this process. The detailed diagnostics also help administrators pinpoint the session hosts where upgrade has failed, and those session hosts that are running an outdated OS, agent, or side by side stack.

Total sessions

Indicates the total number of user sessions on this host pool.

Number

Active sessions

Indicates the total number of sessions that are currently active on this host pool.

Number

Compare the value of this measure across host pools to know which host pool is overloaded with user sessions. Host pools that have or are about to reach their maximum session limit can also be quickly identified this way.

Use the detailed diagnosis of this measure, if enabled, to know the names and types of active sessions on the host pool. Who initiated the session, when, and to which session host in the pool, are also revealed.

Unknown sessions

Indicates the number of sessions on this host pool that are in an Unknown state.

Number

Use the detailed diagnosis of this measure, if enabled, to know which sessions are in an Unknown state.

Pending sessions

Indicates the number of pending sessions on this host pool.

Number

Use the detailed diagnosis of this measure, if enabled, to know which sessions are pending completion on the host pool.

Logoff sessions

Indicates the number of sessions that have logged out of this host pool.

Number

The detailed diagnosis of this measure , if enabled, reveals the names and types of the logged of sessions.

User profile disk mount sessions

Indicates the number of sessions on this host pool, where user profiles in FSLogix containers are dynamically attached to the computing environment at sign in, using natively supported VHD and VHDX.

Number

The detailed diagnosis of this measure, if enabled, reveals the details of sessions where user profiles are dynamically attached to the computing environment. .

Powered off hosts

Indicates the number of hosts in this host pool that are currently powered off.

Number

To know which hosts in the pool are powered off, use the detailed diagnosis of this measure.

Drain mode hosts

Indicates the number of hosts in this pool for which the 'Drain mode' has been turned on.

Number

Drain mode isolates a session host when you want to apply patches and do maintenance without disrupting user sessions. When isolated, the session host will not accept new user sessions. Any new connections will be redirected to the next available session host. Existing connections in the session host will keep working until the user signs out or the administrator ends the session. When the session host is in drain mode, admins can also remotely connect to the server without going through the Azure Virtual Desktop service.

To know for which session hosts in the pool the 'drain mode' has been set, use the detailed diagnosis of this measure.

No heart beat hosts

Indicates the number of session hosts in this host pool, from which no heartbeat was received during the last measurement period.

Number

The monitoring agent used by Azure Monitor often sends a heart beat from each session host every minute to indicate the availability of the session. The value of this measure represents the number of session hosts in a pool from which no such heartbeats were received - i.e., the number of hosts that are down.

Ideally therefore, the value of this measure should be 0. If a non-zero value is reported, then use the detailed diagnosis of this measure to identify the session hosts that have not sent any heartbeats during the last measurement period.

Idle hosts

Indicates the number of idle session hosts in this host pool.

Number

Since idle hosts unnecessarily drain a pool's collective resources, its best that the value of this measure is low at all times. If this measure reports an unusually high value, then use the detailed diagnosis of the measure to identify the idle hosts in the pool.

Disconnected hosts

Indicates the number of session hosts in this pool that are disconnected from the AVD broker.

Number

Ideally, the value of this measure should be 0. If a non-zero value is reported, then use the detailed diagnosis of this measure to know which hosts in the pool are disconnected from the broker.

Unavailable hosts

Indicates the number of session hosts in this host pool that are unavailable.

Number

Ideally, the value of this measure should be 0. If a non-zero value is reported, then use the detailed diagnosis of this measure to know which hosts in the pool are unavailable.

Upgrade failed hosts

Indicates the number of session hosts in this pool, on which the virtual desktop agent could not be upgraded.

Number

Ideally, the value of this measure should be 0. If a non-zero value is reported, then use the detailed diagnosis of this measure to know on which hosts the virtual desktop agent upgrade failed.

Upgrading hosts

Indicates the number of session hosts on which the virtual desktop agent upgrade is in progress.

Number

To know the hosts on which upgrade is in progress, use the detailed diagnosis of this measure.

Available hosts

Indicates the number of session hosts in this host pool, which are available.

Number

To know the available hosts in a host pool, use the detailed diagnosis of this measure.

Healthy beat hosts

Indicates the number of session hosts in this host pool, which are sending out heart beats at scheduled intervals.

Number

Connection allowed hosts

Indicates the number of session hosts in this host pool that are ready to accept connections.

Number

Use the detailed diagnosis of the Status measure to view the friendly name of the host pool, host pool type, load balancer type, and maximum number of sessions allowed on the host pool.

Figure 3 : The detailed diagnosis of the Status measure reported by the AVD Session Hosts By Host Pools test

Use the detailed diagnosis of the Total session hosts measure to know which session hosts are in the host pool, where they are located, and what the current status of each session host is. Unavailable session hosts in the pool can be identified in this process. The detailed diagnostics also help administrators pinpoint the session hosts where upgrade has failed, and those session hosts that are running an outdated OS, agent, or side by side stack.

Figure 4 : The detailed diagnosis of the Total session hosts measure

To know for which session hosts in the pool the 'drain mode' has been set, use the detailed diagnosis of the Drain mode hosts measure.

Figure 5 : The detailed diagnosis of the Drain mode hosts measure

Use the detailed diagnosis of the No heart beat hosts measure to identify the session hosts that have not sent any heartbeats during the last measurement period.

Figure 6 : The detailed diagnosis of the No heart beat hosts measure

Use the detailed diagnosis of the Idle hosts measure to identify the idle hosts in the pool.

Figure 7 : The detailed diagnosis of the Idle hosts measure

Use the detailed diagnosis of the Unavailable hosts measure to know which hosts in the pool are unavailable.

Figure 8 : The detailed diagnosis of the Unavailable hosts measure

Use the detailed diagnosis of the Available hosts measure to know which hosts in the pool are available.

Figure 9 : The detailed diagnosis of the Available hosts measure