Memory Usage - OS Test

How often should the test be executed.

The host for which the test is to be configured.

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

To enable the eG agent to connect to the XenServer API for collecting statistics of interest, this test should login to the target hypervisor 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 Citrix Hypervisor:

• Modify the target hypervisor's configuration in the eG Enterprise. For this, follow the Infrastructure -> Components -> Add/Modify menu sequence, pick Citrix Hypervisor as the Component type, and click the Modify button corresponding to the target hypervisor.
• 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.

The password of the specified Xen User needs to be mentioned in the Xen Password text box.

Then, confirm the Xen Password by retyping it in the Confirm Password text box.

By default, the Citrix Hypervisor is not SSL-enabled. This indicates that by default, the eG agent communicates with the target hypervisor using HTTP. Accordingly, the SSL flag is set to No by default. If you configure the target hypervisor to use SSL, then make sure that the SSL flag is set to Yes, so that the eG agent communicates with the target hypervisor using HTTPS. Note that a default SSL certificate comes bundled with every Citrix Hypervisor installation. If you want the eG agent to use this default certificate for communicating with an SSL-enabled Citrix Hypervisor, 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 target hypervisor. In such a case, you need to explicitly follow the broad steps given below to enable the eG agent to communicate with the target hypervisor via HTTPS:

• Obtain the server-certificate for the Citrix Hypervisor
• 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.

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.

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.

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 Citrix Hypervisor 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.

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.

By default, the eG agent does not support the inside view for VMs executing on Windows operating systems. Accordingly, the IGNORE WINNT flag is set to Yes by default.

By default, in most virtualized environments, the target hypervisor listens on port 80 (if not SSL-enabled) or on port 443 (if SSL-enabled). This implies that while monitoring an SSL-enabled Citrix hypervisor, the eG agent, by default, connects to port 443 of the server to pull out metrics, and while monitoring a non-SSL-enabled Citrix hypervisor, 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 target hypervisor in your environment listens so that the eG agent communicates with that port.

Typically, when performing VM discovery, the eG agent automatically discovers the operating system on which every VM runs, and all the IP addresses that each VM supports. If two are more VMs on a target vSphere server are in a VM cluster, then the eG agent will also auto-discover the cluster IP address. Since the cluster IP address is shared by all VMs in the cluster, this IP address will be in the discovery list of every VM in the cluster. In this case, if the eG agent attempts to obtain the 'inside view' of each VM in a cluster using their cluster IP address, incorrect metrics may be reported sometimes. To avoid this, you may want to instruct the eG agent to not use the cluster IP address when collecting 'inside view' metrics. For this, specify a comma-separated list of cluster IP addresses to be excluded in the EXCLUDE IP text box.

By default, the detailed diagnosis of the Used physical memory measure of this test reports the number of instances of each process running on the VM, and the aggregated memory usage (in MB and %) of every process across all its instances. For example, if users to a VM are together having 15 instances of Chrome open on the machine at around the same time, then the detailed diagnosis of the Used physical memory measure will compute and display the collective memory usage of all 15 instances against the Application Name, Chrome. From this, you can quickly identify the exact process that is 'collectively' (i.e., across its instances) over-utilizing the memory. Sometimes, administrators might want to isolate not just the process, but also similar process arguments that are guilty of abnormal memory consumption. This granular insight will take administrators closer to the root-cause of the memory bottleneck on a desktop. For instance, in the Chrome example above, say 8 of the 15 instances are used to access the same YouTube video, and 7 instances are accessing a shopping site. In such a case, if memory usage is aggregated at the URL-level and not the process-level, then administrators can quickly identify which precise URL is draining memory - the YouTube video? or the shopping site? For this, detailed diagnostics should be grouped by process arguments (eg., URLs) and not just by process/application names. To enable grouping by arguments, set the Group Processes With Arguments flag to Yes. By default, this flag is set to No.

By default, this parameter is set to 75 percentage indicating that by default this test will display top-10 memory intensive processes on a VM in the detailed diagnosis of the Physical memory utilized measure only when the memory utilization reaches/exceeds 75 percentage. On the other hand, if the memory utilization is lower than the value specified against this parameter, then, this test displays only top-3 memory intensive processes in the detailed diagnosis of the Physical memory utilized measure so as to conserve storage space on the database. However, this setting can be overridden if required.

A memory shortage caused due to memory space hogged by modified and standby memory lists has become an increasingly frequent and critical problem. The memory shortage can make a server stutter or run more slowly than usual. Such operational interruptions can make you spend more time on waiting for pages and programs to load, disturbing your work flow and leading to work delays. Moreover, memory shortage can not only impair user productivity, but can also bring crucial business processes to a halt, and can severely degrade overall user experience with the server. To avoid such an outcome, administrators need to rapidly empty the memory space unnecessarily hogged by the modified and standby memory lists. This way, administrators can ensure that adequate memory is always available for executing business-critical processes.

To enable administrators to achieve this, eG Enterprise offers 'Automation Actions'. These actions are governed by the 'Automation Action Enabled' flag.

This flag, if enabled, automatically initiates user-configured actions, so that the memory hogged by modified and standby memory lists can be cleared when memory utilization crosses a configured limit.

Note:

The 'Automation Action Enabled' parameters, once configured, will apply only to the chosen component. These settings will not be applied to other components even if the Apply to other components button is clicked in the Specific Test Configuration page.

This flag appears only if the Automated Action Enabled flag is enabled.

In this text box, specify the upper limit for memory utilization in percentage beyond which this test should trigger user-configured automation actions. By default, 95 percentage is set against this parameter. When the memory utilization reaches/exceeds the value specified in this text box, the user-configured actions will be automatically triggered. However, you can override this settings if required.

This flag appears only if the Automated Action Enabled flag is enabled.

Modified memory contains cached data and code that is not actively in use by processes, the system and the system cache. This memory needs to be written out before it will be available for allocation to a process or for system use. You can easily clear this memory using the Empty Modified Memory flag.

By default, this flag is set to No. When this flag is set Yes, amount of memory assigned to the modified list will be automatically cleared if the memory utilization reaches/exceeds the value specified against the Automation Memory Limit parameter.

This flag appears only if the Automated Action Enabled flag is enabled.

Standby memory is a page of physical memory that is not actively used. When writing a series of frequently used information in the memory area, the programs and services running on the server will use part of memory as cache. The cache should be released and made available after executing programs and services. If the standby memory is not cleared on a regular basis, it can slow down the server operations. Therefore, it is necessary to clear the standby memory at regular intervals. This can easily done using the Empty Standby Memory flag.

By default, this flag is set to No. When this flag is set Yes, memory that is allocated to the standby page list will be automatically cleared if the memory utilization reaches/exceeds the value specified against the Automation Memory Limit parameter.

While monitoring a Citrix hypervisor, the REPORT BY USER flag is set to No by default, indicating that by default, the guest operating systems on the target hypervisor are identified using the host name specified in the operating system. On the other hand, while monitoring a Citrix hypervisor-VDI, this flag is set to Yes by default; this implies that in case of the Citrix hypervisor-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.

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.