eG Monitoring
 

Measures reported by AzrSessHostTest

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 AzrSessHostTest.

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.

Outputs 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

The measures made by this test are as follows:

Measurement Description Measurement Unit Interpretation
Status Indicates whether/not this host pool is available currently.   The values reported by this measure and its numeric equivalents are mentioned in the table below:

Measure Value Numeric Value
Unavailable 0
Available 1


Note:

By default, this measure reports the above-mentioned Measure Values displayed 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.
Diskmount_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.
PoweredOff_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.
Heart_rate_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.
Disonnected_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.
UpgradeFailed_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  
Conn_allowed_hosts Indicates the number of session hosts in this host pool that are ready to accept connections. Number