Resource Usage

While in beta, usage of rngo is free, but limited based upon simulation output volume:

• the maximum volume for a single simulation is 100 MB
• the maximum aggregate volume per user per day is 1 GB

All simulations are also limited to a fixed state volume of 64 MB, regardless of output volume.

Output Volume

A simulation's output volume is the sum of each stream's output volume, which is calculated by taking the product of:

1. stream length - the maximum number of events that the stream could produce given the simulation spec.
2. schema width - the number of bytes required to store the largest value described by the stream's schema.

The output volume is this number rounded up to the next megabyte.

Stream Length

A stream's length is the maximum number of events that the stream could produce given the simulation specs.

Fixed Rate

If the stream has a fixed rate, the length is the rate multiplied by the simulation duration in seconds.

Variable Rate

If the stream has a variable rate, the length is calulated by partitioning the domain of the function and summing the maximum of each partition's upper- and lower-bound rate.

See the Streams reference for more on rates.

Schema Width

A schema's width is the number of bytes required to store the largest value described by the schema.

Null

A null schema's width is 1.

Boolean

A boolean schema's width is 1.

Integer

An integer schema's width is large enough to fit it's upper bound. For example, the following schema has width 3:

type: integer
maximum: 65600

The width must also accommodate the lower bound - this schema also has width 3:

type: integer
minimum: -65600
maximum: 128

Upper and lower bounds may also be derived from the exclusiveMinimum, exclusiveMaximum keywords, along with from rngo.value expressions.

If no bounds are specified, we use a default minimum of -2147483648 and a maximum of 2147483647, so the following schema has a width of 4:

type: integer

Number

A number schema's values are represented as integers, with the 4 least significant digits representing the fractional part. So the following schema has a width of 3:

type: number
minimum: 0
maximum: 32

This is because the largest possible value is represented as 320000, which requires 3 bytes. This schema has width of 4 to accomodate the integer 20458900:

type: number
minimum: -2045.89
maximum: 32

String

A string schema's width is the length of the longest possible string multiplied by 4, so this schema has a width of 80:

type: string
maxLength: 20

The width may also be derived from the pattern and format keywords, along with from rngo.value expressions.

If no keywords are specified, we use a default maxLength value of 64, meaning ther following schema has a width of 256:

type: string

Array

An array schema's width is the maximum length of the array times the size of its items. So the following schema has a width of 5:

type: array
items:
  type: integer
  minimum: 0
  maximum: 128
maxItems: 5

If maxItems is not specified, we use a default value of 64

Object

An object schema's width is the sum of the width of its values. This schema has a width of 19:

type: object
properties:
  id:
    type: integer
    mimum: 0
    maximum: 512
  name:
    type: string
    maxLength: 4
  admin:
    type: boolean

Widths are calculated recursively, so the following schema has a width of 127:

type: object
properties:
  id:
    type: integer
  posts:
    type: array
    items:
      type: object
      properties:
        title:
          type: string
          maxLength: 10
        published:
          type: boolean
    maxItems: 3

enum / const

If a schema specifies an enum or a const, the width will be the item with the most bytes. For example, this schema has length 5:

type: string
enum:
  - one
  - two
  - three

Similarly, this schema has width 12:

type: object
enum:
  - name: Alice
    age: 32
  - name: Bob
    age: 45
  - name: Methuselah
    age: 969

State Volume

A simulation may need to maintain state in order to fulfill certain schema definitions, for example to guarantee uniqueness or referential integrity.

Regardless of output volume, a simulation's state volume may not exceed 64 MB; any attempt to run such a simulation will result in an error.

You can reduce a simulation's state volume by:

1. reducing the simulation's output volume
2. removing uniqueness constraints
3. removing stream references