VM Connectivity Test

Sometimes, a VM could be in a powered-on state, but the failure of the VM operating system or any fatal error in VM operations could have rendered the VM inaccessible to users. In order to enable administrators to promptly detect such ‘hidden’ anomalies, the eG agent periodically runs a connectivity check on each VM using this test, and reports whether the VM is accessible over the network or not.

Target of the test : An ESX server host

Agent deploying the test : An external agent

Outputs of the test : One set of results for each VM configured on the ESX host being monitored.

Configurable parameters for the test:
Parameter	Description
Test Period	How often should the test be executed
Host	The host for which the test is to be configured
Port	The port at which the specified HOST listens. By default, this is NULL.
ESX User and ESX Password	In order to enable the test to extract the desired metrics from a target ESX server, you need to configure the test with an ESX USER and ESX PASSWORD. The user credentials to be passed here depend upon the mechanism used by the eG agent for auto-discovering the VMs on the target vSphere server and monitoring the server and its VMs. These discovery/monitoring methodologies and their corresponding configuration requirements have been discussed hereunder: Discovering and monitoring by directly connecting to the target vSphere server: Starting with ESX server 3.0, a VMware ESX server offers a web service interface using which the eG agent discovers the guest operating systems on a physical ESX host. The VMware VI SDK is used by the agent to implement the web services interface. To use this interface for discovering the VMs and for monitoring, the eG agent should directly connect to the monitored vSphere/ESX server as an ESX USER with root privileges. However, if, owing to security constraints, you cannot use root user permissions, you can alternatively configure the tests with the credentials of a user who has been assigned the following permissions: Diagnostics TerminateSession To see how you can create such a user on the ESX server, refer to theCreating a Special Role on an ESX Server and Assigning the Role to a New User topic Discovering and monitoring using vCenter: By default, the eG agent connects to each ESX server and discovers the VMs executing on it. While this approach scales well, it requires additional configuration for each server being monitored. For example, separate user accounts may need to be created on each server for accessing VM details. While monitoring large virtualized installations however, the agents can be optionally configured to perform guest discovery using the VM information already available in vCenter. The same vCenter can also be used to monitor the vSphere server and its VMs. In this case therefore, the ESX USER and ESX PASSWORD that you specify should be that of an Administrator or Virtual Machine Administrator in vCenter. However, if, owing to security constraints, you prefer not to use the credentials of such users, then, you can create a special role on vCenter with the following privileges: Diagnostics Change settings View and stop sessions To know how to grant the above-mentioned permissions to a vCenter user, refer to Creating a Special Role on vCenter and Assigning the Role to a New User . If the ESX server for which this test is being configured had been discovered via vCenter, then the eG manager automatically populates the ESX USERand ESX PASSWORD text boxes with the vCenter user credentials using which the ESX discovery was performed.
Confirm Password	Confirm the specified ESX PASSWORD by retyping it here.
SSL	By default, the ESX server is SSL-enabled. Accordingly, the SSL flag is set to Yes by default. This indicates that the eG agent will communicate with the ESX server via HTTPS by default. On the other hand, if the eG agent has been configured to use the VMPerl API or CLI for monitoring (i.e., if the ESX USER parameter is set to none), then the status of the SSL flag is irrelevant. Like the ESX sever, the vCenter is also SSL-enabled by default. If you have chosen to use the vCenter for monitoring all the ESX servers in your environment, then you have to set the SSL flag to Yes.
Webport	By default, in most virtualized environments, the ESX server and vCenter listen on port 80 (if not SSL-enabled) or on port 443 (if SSL-enabled). This implies that while monitoring an SSL-enabled ESX server directly, the eG agent, by default, connects to port 443 of the ESX server to pull out metrics, and while monitoring a non-SSL-enabled ESX server, the eG agent connects to port 80. Similarly, while monitoring an ESX server via an SSL-enabled vCenter, the eG agent connects to port 443 of vCenter to pull out the metrics, and while monitoring via a non-SSL-enabled vCenter, the eG agent connects to port 80 of vCenter. 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 ESX server or vCenter in your environment listens so that the eG agent communicates with that port.
Virtual Center	If the eG manager had discovered the target ESX server by connecting to vCenter, then the IP address of the vCenter server used for discovering this ESX server would be automatically displayed against the VIRTUAL CENTER parameter; similarly, the ESX USER and ESX PASSWORD text boxes will be automatically populated with the vCenter user credentials, using which ESX discovery was performed. If this ESX server has not been discovered using vCenter, but you still want to discover the guests on the ESX server via vCenter, then select the IP address of the vCenter host that you wish to use for guest discovery from the VIRTUAL CENTER list. By default, this list is populated with the IP address of all vCenter hosts that were added to the eG Enterprise system at the time of discovery. Upon selection, the ESX USERand ESX PASSWORD that were pre-configured for that vCenter server will be automatically displayed against the respective text boxes. On the other hand, if the IP address of the vCenter server of interest to you is not available in the list, then, you can add the details of the vCenter server on-the-fly, by selecting the Other option from the VIRTUAL CENTER list. This will invoke the ADD VCENTER SERVER DETAILS page. Refer to Adding the Details of a vCenter Server for VM Discoverysection to know how to add a vCenter server using this page. Once the vCenter server is added, its IP address, ESX USER, and ESX PASSWORD will be displayed against the corresponding text boxes. On the other hand, if you want the eG agent to behave in the default manner -i.e., communicate with each ESX server for monitoring and VM information - then set the VIRTUAL CENTER parameter to ‘none’.
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.
Ignore VMs Inside View	Administrators of some high security VMware 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 an ESX 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.
Inside view using	By default, this test obtains the “inside view” of VMs using the eG VM Agent. Accordingly, the inside view using flag to eG VM Agent by default. The eG VM Agent is a piece of software, which should be installed on every VM on a hypervisor. Every time the eG agent runs this test, it uses the eG VM Agent to pull relevant 'inside view' metrics from each VM. Once the metrics are collected, the eG agent then communicates with each VM agent and pulls these metrics, without requiring administrator privileges. Refer to Configuring the Remote Agent to Obtain the Inside View of VMs for more details on the eG VM Agent.
Report Unavailability	By default, this flag is set to No. This implies that, by default, the test will not report the unavailability of network connection between a user terminal and a virtual desktop. In other words, if the Packet loss measure of this test registers the value 100% for any user, then, by default, this test will not report any measure for that user; under such circumstances, the corresponding user name will not appear as a descriptor of this test. You can set this flag to Yes, if you want the test to report and alert you to the unavailability of network connection between a user terminal and a virtual desktop.
Packet Size	The size of packets used for the test (in bytes)
Packet Count	The number of packets exchanged between the virtual desktop and the user terminal during the test
Packet Interval	Represents the interval (in milliseconds) between successive packet transmissions during the execution of this test.
Timeout	How long after transmission should a packet be deemed lost (in seconds)

Measurements made by the test

Measurement	Description	Measurement Unit	Interpretation
Avg network delay:	Indicates the average delay between transmission of packet to a VM and receipt of the response to the packet at the source.	Secs	An increase in the value of this measure is a cause for concern. Given below are some common reasons for such an anomaly: The network between the VM and the eG external agent is congested. When there is an increase in traffic on the interconnecting network, data transmission can slow down, thereby increasing communication latency. The quality of the network connection between the eG external agent and the VM is sub-par. Poor signal quality, faulty transmission lines, etc. can result in an increase in packet loss and/or network latency. The VM is overloaded. If the VM is very busy, it takes longer to respond to requests, and this will result in an increase in latency. There are problems with network routing between the VM and the eG external agent. A faulty network router, routing loops, etc., can increase network latency. Check the detailed diagnosis of this test to track latency on the first three hops between the agent and the VM. The latency to each hop can be used to determine which hop the problem lies in.
Min network delay:	The minimum time between transmission of a packet and receipt of the response back.	Secs	A significant increase in the minimum round-trip time is often a sure sign of network congestion.
Packet loss:	Indicates the percentage of packets lost during transmission from source to target and back.	Percent	A value close to 100% for this measure is a cause for concern. Given below are some common reasons for such an anomaly: The network between the VM and the eG external agent is congested. When there is an increase in traffic on the interconnecting network, packets may be dropped. The quality of the network connection between the eG external agent and the VM is sub-par. Poor signal quality, faulty transmission lines, etc. can result in an increase in packet loss and/or network latency. The VM is overloaded. If the VM is very busy, it takes longer to respond to requests, and this will result in packet drops. There are problems with network routing between the VM and the eG external agent. A faulty network router, routing loops, etc., can increase packet loss. Check the detailed diagnosis of this test to know the hops that are on the path from the external agent to target VM, and the packet loss on each hop. This information can be used to diagnose the hop(s) that could be causing excessive packet loss.
Network availability of VM:	Indicates whether the network connection is available or not.	Percent	A value of 100 indicates that the VM is connected. The value 0 indicates that the VM is not connected. Typically, the value 100 corresponds to a Packet loss of 0. The value 0 for this measure could mean that the target VM is either down or too busy, or the interconnecting network is down.