Glossary

This glossary defines terms that are specific to AWS SimSpace Weaver.

For the latest AWS terminology, see the AWS glossary in the AWS General Reference.

A

app

Executable code (also called binaries) that you create. The term app can refer to the code or a running instance of that code. An app encapsulates simulation behavior. Apps create, delete, read, and update entities.

app SDK

A software development kit (SDK) that you use to integrate an app with SimSpace Weaver. The SDK provides APIs for reading and writing entity data and tracking simulation time. For more information, see SimSpace Weaver app SDK.

C

client

Processes (or their definitions) that exist outside of SimSpace Weaver and interact with the simulation through a custom app or service app. You can use a client to view or change the simulation state.

clock

An abstraction of SimSpace Weaver's internal scheduling processes. The clock publishes ticks to apps to maintain time synchronization. Each simulation has its own clock.

clock rate

The number of ticks per second that the clock publishes to apps. For more information about supported clock rates, see SimSpace Weaver endpoints and quotas.

clock tick rate

See clock rate.

compute resource unit

A unit of compute resources (processor and memory) on a worker. A single instance of an app is normally allocated 1 compute resource unit. You can allocate more than 1 compute resource unit for each app.

custom app

A type of app that you use to read and interact with the state of the simulation. Custom apps can create entities in the simulation but don't own them. When a custom app creates an entity, it must transfer the entity to the spatial domain. You control the lifecycle of a custom app using the app APIs. For more information about the SimSpace Weaver APIs, see SimSpace Weaver API references.

custom domain

A domain that contains custom apps.

custom partition

The partition of a custom app.

D

deadline

An actual time by which an operation (such as processing for a tick) should be complete.

domain

A group of app instances that run the same executable code (app binary) and have the same launch options.

E

endpoint (service)

A fully-qualified domain name (FQDN) that programs (such as the AWS Command Line Interface) use to connect to the SimSpace Weaver service.

endpoint (simulation)

An IP address and port number that clients use to connect to connect to a simulation. You can configure endpoints on custom apps and service apps.

entity

Customer data objects (or their definitions). Entities can be static (remain in one location) or dynamic (move through the simulation space). For example, people and buildings in a simulation.

I

index (simulation)

A description of the spatial properties of a simulation, including its spatial boundaries and coordinate system.

L

lifecycle (of an app)

A description of the expected logical steps that an app goes through during a simulation. Lifecycles are either managed (SimSpace Weaver starts and stops the app) or unmanaged (you start and stop the app).

load (entity field data)

Read entity field data from the State Fabric.

P

partition

A segment of shared memory on a worker. Each partition contains a discrete subset of entities within a domain. Each app has an assigned partition. An app owns all of the entities in its partition. When an app creates an entity, it creates it in its partition. When entities move from one partition to another partition, ownership transfers from the source partition's app to the destination partition's app.

R

resource unit

See .

S

schema

A YAML or JSON document that describes the configuration of a simulation. SimSpace Weaver uses a schema to create a simulation resource.

service app

A type of app that you use to read and interact with the state of the simulation. Service apps can create entities in the simulation but must transfer them to the spatial domain. SimSpace Weaver manages the lifecycle of a service app, and starts 1 (or more, as specified in your simulation schema) on each worker in your simulation.

service domain

A domain that contains service apps.

service partition

The partition of a service app.

simulation (resource)

An abstraction of a compute cluster that runs a simulated virtual space. You can have multiple simulations. You configure a simulation using a schema.

spatial app

A type of app that encapsulates the core simulation logic. Each spatial app owns 1 (and only 1) partition.

spatial domain

A domain that contains spatial apps.

spatial partition

The partition of a spatial app.

State Fabric

SimSpace Weaver's in-memory database. The State Fabric stores the state of simulations, including entities and internal SimSpace Weaver data.

store (entity field data)

Write entity field data to the State Fabric.

subscription

A long-running request for a specific app instance to receive data from a subscription area. The subscribing app uses a subscription to discover changes to entities inside the subscription area.

subscription area

A 2-dimensional region of the simulation space. A subscription refers to a subscription area. A subscription area can span more than 1 partition, and also include parts of partitions. A subscription area is continuous within its defined bounds.

T

tick

A discrete value for time (either wall-clock time or simulation time). Apps can iterate faster than the tick duration, but are expected to write specified ticks within specific deadlines. All operations for all apps for a given tick must complete before the next tick can start.

tick rate

See clock rate.

time (actual)

The current time from the perspective of reality. SimSpace Weaver uses a 64-bit POSIX timestamp which is the number of nanoseconds since the Unix epoch (January 1, 1970, 00:00:00 UTC).

time (simulation)

The current time from the perspective of the simulation. SimSpace Weaver uses a 64-bit integer logical tick counter, which might not directly correspond to the actual time.

W

worker

An Amazon Elastic Compute Cloud (Amazon EC2) instance that runs simulation code.