Jump toUpdate content

Containers - Concepts

Cold Start

Cold start is the time a container Instance takes to handle a request when it is called for the first time.


Concurrency defines the number of simultaneous requests your container can handle at the same time.


A container is a package of software that includes all dependencies: code, runtime, configuration, and system libraries so that it can run on any host system. Scaleway provides you with custom Docker images that are entirely handled for you in the cloud. With Containers, you can rely on your favorite technologies such as Django or Ruby On Rails.

Container Registry

Container Registry is the place all your images are stored before being deployed.


Unit used to measure the resources consumption of a container. It reflects the amount of memory consumed over time.

Environment Variables

An environment variable is a variable whose value is set outside the program, typically through functionality built into the operating system or microservice. An environment variable is made up of a name/value pair, and any number may be created and available for reference at a point in time.


An image, is a blueprint from which an arbitrary number of brand-new containers can be started. You can start a container from an image, perform operations in it and save another image based on the latest state of the container.

JWT Token

JWT (JSON Web Token) is an access token you can create from the console or API to enable an application to access your Private Container. Consult the Developer documentation for more details.


A vCPU (Virtual Central Processing Unit) is equivalent to 1000 mVCPU.


A namespace is a project that allows you to group your containers. Containers in the same Namespace can share environment variables and access tokens, defined at the namespace level.

Privacy policy

A container’s privacy policy defines whether a container may be invoked anonymously (public) or only via an authentication mechanism provided by the Scaleway API (private).

Scale to zero

One of the advantages of Serverless Container is that when your container is not triggered, it does not consume any resources which enables great savings.


Serverless Containers make scaling your application transparent, up to 20 instances of your container can be run at the same time.


Secrets are an extra-secure type of environment variable. They are environment variables which are injected into your container and stored securely, but not displayed in the console after initial validation.


Serverless allows you to deploy your Functions (FaaS) and Containerized Applications (CaaS) in a managed infrastructure. Scaleway ensures the deployment, the availability and the scalability of all your projects.

Serverless Framework

Serverless.com (Serverless Framework) is a tool that enable to deploy serverless applications without having to manages Serverless Container’s API call. Just write your configuration in a yaml and deploy, it handles everything event image building.

Stateless application

A stateless application is a computer program that does not save client data between sessions. Data generated in one session is not saved for use in the next session with that client. All applications deployed on Serverless Containers are stateless.


The timeout is the maximum length of time your container can spend processing a request before being stopped. This value must be in the range 10s to 900s.


Triggers are a named channel for a class of events. The following are examples of triggers:

  • A trigger of location update events.
  • A trigger of document uploads to a website.
  • A trigger of incoming emails.


vCPU is the abbreviation for virtual Centralized Processing Unit. A vCPU represents a portion or share of the underlying physical CPU assigned to a particular container. The performance of a vCPU is determined by the percentage of time to spend on the physical processor’s core. It is possible to allocate different resource allowances on specific vCPUs for specific containers or virtual machines.


Serverless Containers supports http1 (default) and http2 (h2c). In some cases for example deploying container using gRPC, may require to upgrade the procotol in order to work.