Fission Glossary - List of terms used in Fission.

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Annotation - --ingressannotation

Use --ingressannotation to specify meta data while creating HTTP Trigger and customize their behavior.


An archive is a zip file containing the source code or compiled binaries.


Builder Pod

Builder pod is a specialized pod that builds the source archive and generate a deployment archive.

Build Container

Builder Container compiles function source code into executable binary/files and is language-specific.

Builder Manager

In a nutshell, the builder Manager manages the builds of function source code.

Once an environment that contains a builder image is created, the builder manager will then create the Kubernetes service and deployment under the default namespace to start the environment builder. And once a package that contains a source archive is created, the builder manager talks to the environment builder to build the function’s source archive into a deploy archive for function deployment.

Build Status

Build status indicates the current build status of a package. is a shell script file that is used to create a custom package by installing third party modules present in the requirements.txt file.


Canary Config

A canary config is custom resource used to configure a canary deployment for Fission functions.

Canary Deployment

Canary Deployment is a deployment strategy to deploy a new version of your Fission function to a cluster incrementally with minimal risk in a way that it gradually serves user traffic from 0% to 100%.

Cold Start

It is defined as the setup time that is required for a function to be up and running when it is invoked for the first time in a defined period to serve user requests.


Concurrency refers to the amount of requests a function should process simultaneously.


Controller contains CRUD APIs for functions, triggers, environments, Kubernetes event watches, etc. and proxy APIs to internal 3rd-party services. A client talks to the controller.


Deployment Archive

Deployment archive is an archive file that contains a runnable function.

Duration - Canary Config

Specifies how frequently user traffic needs to be incremented for the new version of function



Environments provide a run time which is used to execute Fission functions. Currently, Fission supports pre-built environments that include NodeJS, Python3, Go, JVM, Ruby, Binary, PHP, .NET and Pearl.


Executor is responsible for spinning up function pods. It retrieves function information from Kubernetes CRD and invokes an executor type to spin up a function pod.


Failure Threshold - Canary Config

Specifies the threshold in percentage beyond which the new version of a function is declared unhealthy.

Failure Type - Canary Config

Specifies the parameter for checking the health of the new version of a function. For now, the only supported type is status-code which is the http status code. So if a function returns a status code other than 200, it is considered to be unhealthy.


Fetcher pulls the source archive from the storage service and verifies the checksum of the file. After the build is complete, it uploads the deployment archive to the storage service.

Fission CLI

Fission CLI is the command line utility that allows you to interact with and operate Fission.

Fission Images

Fission Specs

Fission spec is a declarative way to manage an application’s specification.


A serverless function in Fission.

Function Pod

Function pod is where a Fission function is loaded and executed. A function pod serves HTTP requests it receives from clients.



HTTP Trigger / Route

It is a type of trigger that invokes a Fission function whenever there is an HTTP request. You can specify a relative URL and HTTP method for an HTTP trigger.




Kubernetes Watch Trigger

KubernetesWatchTrigger is a custom resource that watches Kubernetes resource events and invokes functions.


Kubewatcher watches the Kubernetes API and invokes functions associated with watches, sending the watch event to the function.



Logger is a daemonset that forwards function logs to a centralized database service for log persistence. Currently only InfluxDB is supported.



Maximum CPU to be assigned to pod (function in case of New Deploy) (In millicore, minimum 1)


Minimum CPU to be assigned to pod (function in case of New Deploy) (In millicore, minimum 1)

Max Memory

Maximum memory to be assigned to pod (function in case of New Deploy) (In megabyte)

Min Memory

Minimum memory to be assigned to pod (function in case of New Deploy)**(In megabyte)

Max Scale

Maximum number of pods (Uses resource inputs to configure HPA)

Min Scale

Minimum number of pods (Uses resource inputs to configure HPA)

Message Queue Trigger

A message queue trigger listens to messages in a message queue and invokes a function based on the arrival of a message in a queue.


New Deploy

New Deploy is a type of executor that creates a Kubernetes deployment along with a service and a Horizontal Pod Autoscalar (HPA) for function execution.

New Function - Canary Config

Specifies the name of the latest version of the function.


Old Function - Canary Config

Specifies the name of the current stable version of the function.

Once Only

OnceOnly is similar to a Kubernetes Job, it is useful in long-running tasks where only one request is served by one pod. Each request is assured to be served by a new pod.



A package in fission can be a source package or a deployment package. A source package contains your source code and related libraries while a deployment package is the one that has an executable code.

Persistent Volume

A PersistentVolume (PV) is a piece of storage in the cluster that has been provisioned by an administrator or dynamically provisioned using Storage Classes.

Pool Manager

PoolManager manages pools of generic containers and function containers.

Pool Size

The size of pool i.e.: number of pods in a pool.



Requests Per Pod

RequestsPerPod denotes how many requests will be routed to each pod in Pool Manager.


This is a file that lists down all the external 3rd party modules, libraries that are required for your function to execute.


Router is responsible for forwarding HTTP requests to function pods.



Source Archive

Source archive is an archive file that contains the source code.


Specifications (specs) are YAML files that are used to instruct Fission CLI about what objects to create or update.

Storage Service

The storage service is the home for all archives of packages with sizes larger than 256 KB.


Target CPU

This is the CPU utilization limit (in percentage) based on which the HPA adds/removes pods.


A timer invokes a function periodically by sending a request to the router. Suitable for background tasks that need periodic execution.

Time Trigger

TimeTrigger invokes functions based on given cron schedule.

TLS - –ingressTLS

Set this flag to enable TLS termination while creating an ingress.


Toleration is a mechanism in Kubernetes to influence the scheduling of pods.


Trigger configures Fission to use an event to invoke a function.

Trigger - Canary Config

Specifies the name of the http trigger object.




A volume is Kubernetes represents a directory with data that is accessible across multiple containers in a pod.


Weight Increment - Canary Config

Specifies the percentage increase of user traffic towards the new version of the function.