How to estimate a Service Unit Budget

If you select the Custom Resource Bundle, then it is important to understand how much budget your allocation requires. You need to estimate your budget when requesting a Custom Resource allocation, but don't worry if you get it wrong, you can always request more later.

Note: A flavor defines the size of resources (number of virtual CPUs, memory and storage capacity) which together are assigned to your Cloud Computer (Instance/Virtual Machine).

Here are four different methods to help you determine how much budget you need:

1. Recommended Budgets for common use-cases
2. Estimating based on Flavors
3. Estimating based on previous usage patterns
4. Same as last time

1. Recommended Budgets for common use-cases

If you are new to Nectar, the simplest approach is to select one our pre-defined Resource Bundles. Resource Bundles include a "recommended" Service Unit (SU) budget for corresponding to one of the following common use-cases:

• "Like my laptop"
   A typical researcher laptop has 4 cores and 8GB of RAM. That is equivalent to an instance with an m3.medium flavor. The SU cost for an m3.medium for one year is 1,000 SU.
• "A bigger laptop"
  A high end researcher laptop might have 8 cores and 16GB of RAM. That is equivalent to an instance with an m3.large flavor. The SU cost for an m3.large for one year is 2,000 SU.
• "I just want to run a website"
  A typical website to host some web pages, some small web applications, or some datasets needs 2 cores and 4GB of RAM. That is equivalent to an instance with an m3.small flavor. The SU cost for an m3.small for one year is 500 SU.

2. Estimating based on Flavors

If you select the Custom Resource Bundle, and you have a good idea of what kind of Nectar resources you are likely to need, you can do your own estimate calculations based on the flavors.

1. Look at the Nectar Flavors page and work out which one(s) best fit your needs.
2. Take the SU cost per hour (or year) for a chosen flavor and multiply that by the time you intend to run the instance during the allocation period.
3. Sum over all of the instances to get the total budget.

3. Estimating based on previous usage patterns

If you have have been using compute resources (e.g. instances) on the Nectar Cloud for a while, you can view your project usage in the Dashboard.

1. Check out the Usage Trend page to get an idea of how many service units your project has used over time.
2. When the page loads, it will show you data for the past 3 months by default. You can change the date range to a more relevant period if you like.
3. On this page you can see which instances were running, including the flavor, to help you understand the usage breakdown.

4. Same as last time

If you're renewing an allocation, you could simply request the same budget that was approved in the last period. However, in this case it's a good idea to  the Allocation Usage page to make sure your previous budget was appropriate.