Foglight for VMware 5.7.0 - User and Reference Guide


	IMPORTANT: Foglight for Virtualization, Enterprise Edition Virtual Appliance comes pre-configured to support up to 4,000 virtual machines. If you are using this product, there is no need to follow the configuration procedure described in this section.

If additional cartridges and agents are added to the environment, product performance should be monitored and agents moved off of the embedded Agent Manager to reduce the load.

32-bit systems are not recommended for new installations, but are provided for customers upgrading from previous versions. On 32-bit systems, the embedded Agent Manager may be used to run agents monitoring no more than 250 virtual machines. Agents monitoring more than 250 virtual machines should run on an Agent Manager on a separate host. It is not recommend to monitor more than 500 virtual machines in any configuration with Foglight for VMware running on a 32-bit host.

Table 5. Foglight VMware Performance Agent host system requirements
	Minimum CPU	Minimum Memory	Total Monitored VMs
Windows 32-bit	1	4 GB	250
Linux 32-bit	1	4 GB	250
Windows 64-bit	21	4 GB	2000
Linux 64-bit	21	4 GB	2000

1 Additional CPUs may be required for larger environments.

Monitoring more than 4000 virtual machines from a single agent host

The Agent Manager JVM usually requires additional memory to monitor more than 4000 virtual machines. The total number of virtual machines is the total from all vCenters that will be monitored from all VMware Performance agents running on the Agent Manager.

The following calculations are guidelines, not hard and fast rules. Memory requirements can vary greatly from installation to installation with similar VM counts. If insufficient memory is configured, the failure mode is easily recognizable: all agents on the Agent Manager host will go into a broken state after the agent(s) were activated for a short period of time, usually within 24 hours. In addition, the Agent Manager log will contain a line similar to the following:

Caused by: java.lang.OutOfMemoryError: Java heap space

If this is the case, add memory greater than what is shown in the calculations below, in increments of 512 MB until the agents stabilize.

JVM memory requirements for VMware Performance agents are calculated using the following formula:

512 MB + 0.5 MB/VM

According to the above formula, monitoring 4000 virtual machines requires 2560 MB of memory:

512 MB + 2048 MB = 2560 MB

This is the default setting for agents deployed on 64-bit systems.

512 MB + 4096 MB = 4608 MB

This requires a change in the default Agent Manager settings.

To change the JVM memory settings:

Determine the amount of additional memory required. This will be the total from the last step above minus the default value of 2560 MB. In the example above, this is 4608 MB – 2560 MB = 2048 MB.

On the agent machine, open the baseline.jvmargs.config file for editing. The file is located in the <Agent_Manager_home>/state/default/config directory.

Add the following lines to the memory settings section:

vmparameter.0 = "-Xms2048m";

vmparameter.1 = "-Xmx2048m";


	NOTE: If this file has been previously edited have been made to this file, increment the numeric parameters accordingly.

Delete the existing deployed negotiation configuration settings directory:

<Agent_Manager_home>/state/default/config/deployments

Restart the Agent Manager for these settings to take effect.

Host system recommendations

Dedication

When monitoring larger vCenters, the Agent Manager machine hosting the VMware Performance agents should be dedicated to this task. No other Foglight agent types should run on the host and the host should not run any other applications.

Memory

Regardless of the values set for JVM memory above, Agent Manager never allocates more than 80% of system memory. So the machine hosting the Agent Manager and VMware Performance Agents must have sufficient memory. Beyond the memory requirements of the Agent Manager, a minimum of 2 GB should be free for the operating system. In the example above for 8000 VMs and an Agent Manager memory requirement of 4608 MB, the host should have a minimum of 6656 MB - the greater of:

1.25 x 4608 MB = 5760 MB

Or:

2048 + 4608 MB = 6656 MB

If the Agent Manager is configured on a virtual machine, it is recommended that the VM use a memory reservation to ensure maximum performance.

CPU

CPU usage on the Agent Manager host is relatively low most of the time. However, usage peaks dramatically during the performance metric collection. This is normal and expected. CPU utilization consistently over 50% is an indication that additional processing power is required. As with memory, usage can vary between different installations with similar numbers of virtual machines. The following guidelines should be followed.

Table 6. CPU usage guidelines
Up to 1000 VMs	2 CPUs
1000 – 4000 VMs	4 CPUs
4000+ VMs	add 1 CPU per 1000 VMs – round up when necessary

When the Agent Manager and VMware Performance agents are running on a virtual machine, the VM should be configured with CPU reservation whenever possible to ensure best performance. Lack of processing power on the Agent Manager manifests in missed collections and gaps in the data usually noticeable in various graphs throughout the Foglight for VMware dashboards.

Configuring agent properties

When an agent connects to Foglight™, it is provided with sets of properties that it uses to configure its correct running state. Each agent is provided with a combination of two types of properties: agent properties and shareable properties.

Default versions of these properties are installed with Foglight for VMware. However, you can edit the default shareable and agent properties, configure agent properties that apply only to a specific agent instance, and create edited clones of shareable properties that are used by a subset of agents of a certain type.

There are two ways to access the VMware Performance Agent properties:

•

On the VMware Environment dashboard, on the Administration tab, select an agent instance and click Edit Properties (see Configuring monitoring agents for data collection ). This method only provides access to the Configuration properties, but not the Black List and Data Collection Scheduler properties.

•

On the Agent Status dashboard, select an agent instance and click Edit Properties. This method provides access to the full set of VMware Performance Agent properties, and is described in this topic.

For more information about working with agent properties, see the Administration and Configuration Guide.

To modify agent properties:

Ensure that the navigation panel is open.

To open the navigation panel, click the right-facing arrow

on the left.

Navigate to the VMware Performance Agent properties. An agent instance can have a combination of global and private properties. Global properties apply to all instances of the agent type, while private properties apply only to specific agent instances.

On the navigation panel, under Dashboards, choose Administration > Agents > Agent Status.


	IMPORTANT: Another way of editing the VMware Performance Agent properties is through the Agent Properties dashboard. The properties you specify on this dashboard apply to all instances of the VMware Performance Agent type. To be certain that you are editing properties for a particular agent instance, without overwriting any properties of other VMware Performance instances, use the Agent Status dashboard instead of the Agent Properties dashboard.

On the Agent Status dashboard, select the instance of the VMware Performance Agent whose properties you want to modify and click Edit > Edit Properties.

Click Modify the private properties for this agent to indicate that you want to edit the properties of the selected VMware Performance Agent instance.

A list of agent properties appears in the display area.

Figure 88. VMware Performance Agent properties