A rater is a metric used to assign a billable charge to the use of a resource—or part of a resource—over a set amount of time. This converts resource usage data into currency values. There are three types of raters:
Allocation Raters: These raters can only be attached to virtual machines. They take a cost for a virtual machine server resource and assign an appropriate percentage of that cost to each virtual machine the rater is attached to, based on the usage of that resource.
Flat Raters: These raters assign a value to a resource at a fixed rate. For example, a flat rater charge for used disk space could be $1 per gigabyte of disk space used per month.
Tiered Raters: These raters assign values to a resource with different flat rates for different levels of usage. For example, a tiered rater charge for memory used could be $0 for 0-512 MB and $.05 per MB for use per day above 512 MB.
Review the following sections:
Raters calculate charges either according to the maximum use of a resource, or according to the average use during a specific time period. The exception is when they charge against hourly data, where charges are calculated using the average use only.
Table 7-1 Rater Resources
|
Resource |
Description |
|---|---|
|
Uptime (Hours) |
The charge is based on the number of hours the network entity has been monitored by PlateSpin Recon during the time specified in the report. and are dimmed for Flat and Tiered Raters. is also dimmed for Allocation Raters. |
|
VC_ProcessorTime (hour) |
The hourly average usage is computed and the sum of all the hour averages during the time specified in the report is used for the charge. and are dimmed. |
|
Processor (MHz) Memory Used(MB) Network (MB/sec) Disk (MB/sec) Disk Space Used (GB) Disk Writes (MB/sec) |
Selecting the Hour forces the use of the Average value, even if Maximum is selected. |
|
Total Processor (Count) |
Static counter. The charge is made against a static value. and are dimmed. |
|
Total Memory (MB) |
Static counter. The charge is made against a static value. and are dimmed. |
|
Total Disk (GB) |
Static counter. The charge is made against a static value. and are dimmed. |
NOTE:Aside from VC_ProcessorTime, described in the preceding table, VC_specific counters are not required nor useful for chargeback, and as a result are not available when creating raters. Use the standard memory counters (Memory Used and Total Memory) as needed.
Flat and Tiered raters: Charge represents the amount of cost assigned to a machine for every measure of usage. For example, for every 3 GB of disk space used per week, apply the charge. For Tiered raters, a Charge value must be entered for each tier.
Allocation raters: Charge represents the total cost of a virtual machine server resource. For example, a rater could include a charge of $1000 per month for virtual machine server disk space. Every virtual machine to which the rater is attached is assigned a percentage of the $1000, proportional to its usage of the selected resource. For example, based on the above rater, if a virtual machine server contains 3 virtual machines that use 50%, 25%, and 10% of its disk space, respectively (either Virtual Server Usage or Virtual Server Capacity), they are assigned $500, $250, and $100 per month in chargeback costs.
IMPORTANT:When using Chargeback with Solaris Zones, allocation raters calculate utilization charges against the host, not the zone, using the formula:
charge = unit price * (zone total resource / host total resource)
If the zone and the host have the same number of resources—CPU, disk or memory—then the result is as expected; but if they differ, unexpected results could be seen in the Cost Allocation report.
For example, if the host has two CPUs but the zone only has one and the charge in the rater for the Processor resource is specified as $1, then with the above formula the resulting charge would be $0.50.
If the host has a considerably larger number of resources compared to the zone, especially when looking at memory and disk resources, the resulting charge could be very small. Since the Chargeback Cost Allocation report displays only two decimal places, the conversion could theoretically lose these small values and the charge on the report could appear as zero.
The Virtual Server Rater Method determines whether the cost assigned to any virtual machine the rater is attached to is calculated based on its percent of usage of the virtual machine server total Virtual Server Usage for that resource, or based on its percent of usage of the virtual machine server total Virtual Server Capacity for that resource.
For example, if a virtual machine server has 1000 GB of disk space, but only 800 are actually used, a virtual machine using 200 GB of disk space is using 20% of Virtual Server Capacity, or 25% of Virtual Server Usage. For a Charge of $1000/month, the virtual machine would be charged $200 if Virtual Server Capacity is selected, but $250 if Virtual Server Usage is selected.