Democratize Serverless Platform With Knative

Mahesh Veerabathiran Guhan Selvaraj

Is Serverless only FaaS?

Serverless is a pattern of sharing responsibilities between

developers and operators.

How To Fit In

• Should we change the way we code?

• Should we switch to another language to

fit in?

• Should we change our deployment

pipeline to conform to cloud provider

services?

Existing hosted serverless platforms

Source: https://landscape.cncf.io/format=serverless

FaaS Providers Comparison

AWS GOOGLE AZURE

• Supports Java, Go,

PowerShell, Node.js, C#,

Python, and Ruby

• Supports Node.js (6 & 8),

Python (Beta), and Go (Beta)

• Supports C#, F#, Node.js (6,

8, 10), Java (v8 Preview),

Python (Preview)

• Should implement handler

function from AWS libraries

to execute the application

business logic

• Limitations on migrating

existing services to

serverless platform

• Limitations on migrating

existing services to

serverless platform

• Can be invoked only through

AWS specific triggers

• No platform specific libraries

required for implementation

• Implements platform specific

libraries, create json files

COLD START

Vendor lock-in

• Cannot avoid it after modifying application

to run in vendor environment.

• Closes the door for easy migration.

• Step functions are cool, but now you’re in

their web.

• Forced to use provider specific monitoring

and tracing tools.

• Integrating with other open-source solutions is

cumbersome.

• Get isolated from rest of enterprise services

monitoring dashboard.

Varied monitoring

PA

IN A

RE

AS

“Kubernetes is a Leading Container Orchestrator for cloud

native application, it governs container orchestration,

scheduling and cluster management”

“K8s is the de-facto standard for container orchestration”

Reasons to love K8s

Load balancing &

Autoscaling are built

into K8s core.

Supports rolling

updates by default.

Ensure zero-downtime

deployments

Native features to

implement Blue/Green

& Canary deployment

Failover built-in. K8s

maintains desired

state.

Cloud provider

agnostic. Supports

Multi-cloud & Hybrid

infra.

Well defined

specification for CRI,

CSI. #Extensible

Beyond stateless workloads

Source: The State of k8s 2018 by Heptio

K8s motivates OSS adoption

Kubernetes appears to be

helping build people’s

confidence in open source

software as a whole.

Source: The State of k8s 2018 by Heptio

“K8s is an operating system for the cloud native world”

How K8s transforming Serverless landscape

K8s closes the gap between container & serverless workloads.

They are not poles apart, in fact, they have lot in common!

Containers Orchestrator Image registry

*Ownership and Abstraction differs!

Container vs Serverless

Knative

Knative leverages the strong foundation of K8s and built middleware

components to support capabilities similar to managed service platform.

An opensource serverless add-on built on K8s

Knative current partners includes IBM, Pivotal, RedHat

Knative embraces Istio, an open-source service mesh, to

connect, secure, control & observe traffic.

Source: https://github.com/knative/docs

Knative - Primitives

E.g. Simple function deployment manifest

apiVersion: serving.knative.dev/v1alpha1 # Current version of Knative

kind: Service

metadata:

name: hello-go # The name of the app

namespace: default # The namespace the app will use

spec:

runLatest:

configuration:

revisionTemplate:

spec:

container:

image: gcr.io/devfestkc/hello-go # container image

env:

- name: TARGET # environment variable

value: "Hello everyone!"

Serving - Under the hood

KNATIVE SERVICE

CONFIGURATION

Revision

DEPLOYMENT

P P P

DEPLOYMENT

P P P

DEPLOYMENT

P P P

ROUTES

P => K8s Pod

Revision

Revision

Leverage Istio

ingress gateway

to route traffic to

pinned or latest

version

Configuration maintains revision

of point-in-time snapshot of

function code & config.

Manages the desired

state of deployment.

Scale up pods and

back to zero based

on demand

Higher order K8s resource for

managing lifecycle of a SLS

workload

Supports autoscaling on-demand as good as any

cloud provider’s serverless platform.

Two built-in types:

- Concurrency based autoscaler

- CPU usage based autoscaler

Fine grained control of lower and upper bound

configuration of pod autoscaling at function level

Defaults to scale up a pod for

every 1000 concurrent requests

Defaults to scale up a pod when current

CPU usage exceeds 80 percent

Provides superior configuration

control and transparency in

autoscaling.

Avoid cold-start issues by disabling scale

back to zero.

Configuration support of defining global

autoscaling parameters.

Supports blue-green deployment

apiVersion: serving.knative.dev/v1alpha1

kind: Route

metadata:

name: blue-green-demo

namespace: default

spec:

traffic:

- revisionName: blue-green-demo-00001

percent: 100 # All traffic still going to the first revision

- revisionName: blue-green-demo-00002

percent: 0 # 0% of traffic routed to the second revision

name: v2 # A named route

@mahes

hvra

https://www.linkedin.com/in/a

boutmahesh

Thank you!

Questions?

Appendix

• Need to re-implement in either go,

python, node.js for better

performance.

• Implement pingers to prevent

applications from going cold.

• Increased cold start time when

implemented in VPCs.

Cold start Code portability

• Code needs to be changed to extend

provider specific interfaces to expose

as a service.

• Forced to change the code to satisfy

the SDKs provided by platform.

• New configurations are needed to

provide access to the service.

OSS FAAS frameworks

• Knative

• Openfaas

• Nuclio

• Fission

• Kubeless

• Project Riff

“Kubernetes does the things that the very best system administrator

would do: automation, failover, centralized logging, monitoring. It takes

what we’ve learned in the DevOps community and makes it the default,

out of the box” – Kelsey Hightower

The state of OSS FAAS Adoption in enterprise

K8s was not the first one to

hit market. ECS is still being

used largely by early

adopters.

Since most of the enterprise

workloads are stateless in

nature, don’t see a enough

reason to move to k8s.

Early adopters of containers Operational burden NoOps movement

K8s has strong reputation of

being complex and involves

steep learning curve.

Any container orchestrator

brings in operational

maintenance which is

frowned upon.

Fall of DevOps this year,

followed by overwhelming

support request to DPE

teams, leading to the path

of NoOps.

Enterprise loves fully

managed services.

“K8s mainstream adoption is critical to the success

of Knative and other OSS FAAS.”

K8s has enough features beyond the dream of multi-cloud.

Managed K8s service will thrive and increase adoption.

EKS enterprise readiness is very important for next wave of adoption.

Knative attempts to bring life to the concept of Funtainers.

The concept has lot of potential to become a standard