Service Meshes

why you need one

and

which one you need

Lee Calcote

calcotestudios.com/talks

November 2019

Lee Calcote

linkedin.com/in/leecalcote

@lcalcote

gingergeek.com

lee@calcotestudios.com

cloud native and its management

calcotestudios.com/talks

github.com/leecalcote

@lcalcote

DEV

OPS

Decoupling at Layer 5

where Dev and Ops meet

Problem: too much infrastructure code in services

What do we need?

• Observability

• Logging
• Metrics
• Tracing

• Traffic Control

• Resiliency

• Efficiency
• Security

• Policy

@lcalcote

...a Service Mesh

What is a Service Mesh?

a dedicated layer for managing service-to-service communication

@lcalcote

So, a microservices platform?

obviously.

partially.

a services-first network

BookInfo Sample App

Reviews v1

Reviews Pod

Reviews v2

Reviews v3

Product Pod

Details Container

Details Pod

Ratings Container

Ratings Pod

Product Container

Reviews Service

Ratings Service

Details Service

Product Service

BookInfo Sample App on Service Mesh

Reviews v1

Reviews Pod

@lcalcote

Reviews v2

Reviews v3

Product Pod

Details Container

Details Pod

Ratings Container

Ratings Pod

Product Container

Envoy sidecar

Reviews Service

Enovy sidecar

Envoy ingress

Product Service

Ratings Service

Details Service

Observability

what gets people hooked on service metrics

@lcalcote

Goals

Metrics without instrumenting apps
Consistent metrics across fleet
Trace flow of requests across services
Portable across metric back-end providers

You get a metric! You get a metric! Everyone gets a metric!

Traffic Control

control over chaos

@lcalcote

Traffic splitting
- L7 tag based routing?
Traffic steering
- Look at the contents of a request and route it to a specific set of instances.
Ingress and egress routing

Resilency

Systematic fault injection
Timeouts and Retries with timeout budget
Control connection pool size and request load
Circuit breakers and Health checks

content-based traffic steering

Missing: application lifecycle management, but not by much

Missing: distributed debugging; provide nascent visibility (topology)

Relating to

Service Meshes

Which is why...

I have client-side libraries.

@lcalcote

Enforcing consistency is challenging.

Foo Container

Flow Control

Foo Pod

Go Library
A v1

Network Stack

Service Discovery

Circuit Breaking

Application / Business Logic

Bar Container

Flow Control

Bar Pod

Go Library
A v2

Network Stack

Service Discovery

Circuit Breaking

Application / Business Logic

Baz Container

Flow Control

Baz Pod

Java Library
B v1

Network Stack

Service Discovery

Circuit Breaking

Application / Business Logic

Retry Budgets

Rate Limiting

Which is why...

I have a container orchestrator.

@lcalcote

Core

Capabilities

Cluster Management
- Host Discovery
- Host Health Monitoring
Scheduling
Orchestrator Updates and Host Maintenance
Service Discovery
Networking and Load Balancing
Stateful Services
Multi-Tenant, Multi-Region

Additional

Key Capabilities

Application Health and Performance Monitoring
Application Deployments
Application Secrets

@lcalcote

minimal capabilities required to qualify as a container orchestrator

Service meshes generally rely on these underlying layers.

Which is why...

I have an API gateway.

@lcalcote

Microservices API Gateways

Ambassador uses Envoy
Kong uses Nginx
OpenResty uses Nginx
Traefik

north-south vs. east-west

Why use a Service Mesh?

to avoid...

Bloated service code
Duplicating work to make services production-ready
- Load balancing, auto scaling, rate limiting, traffic routing...
Inconsistency across services
- Retry, tls, failover, deadlines, cancellation, etc., for each language, framework
- Siloed implementations lead to fragmented, non-uniform policy application and difficult debugging
Diffusing responsibility of service management

@lcalcote

Help with Modernization

@lcalcote

Can modernize your IT inventory without:
- Rewriting your applications
- Adopting microservices, regular services are fine
- Adopting new frameworks
- Moving to the cloud

address the long-tail of IT services

Get there for free

Service Mesh Architectures

Service Mesh Architecture

@lcalcote

Data Plane

Touches every packet/request in the system.
Responsible for service discovery, health checking, routing, load balancing, authentication, authorization, and observability.

Ingress Gateway

Egress Gateway

Service Mesh Architecture

@lcalcote

No control plane? Not a service mesh.

Control Plane

Provides policy, configuration, and platform integration.
Takes a set of isolated stateless sidecar proxies and turns them into a service mesh.
Does not touch any packets/requests in the data path.

Data Plane

Touches every packet/request in the system.
Responsible for service discovery, health checking, routing, load balancing, authentication, authorization, and observability.

Ingress Gateway

Egress Gateway

Service Mesh Architecture

@lcalcote

Control Plane

Data Plane

Touches every packet/request in the system.
Responsible for service discovery, health checking, routing, load balancing, authentication, authorization, and observability.

Provides policy, configuration, and platform integration.
Takes a set of isolated stateless sidecar proxies and turns them into a service mesh.
Does not touch any packets/requests in the data path.

You need a management plane.

Ingress Gateway

Management
Plane

Provides monitoring, backend system integration, expanded policy and application configuration.

Egress Gateway

Pilot

Citadel

Mixer

Control Plane

Data Plane

istio-system namespace

policy check

Foo Pod

Proxy Sidecar

Service Foo

tls certs

discovery & config

Foo Container

Bar Pod

Proxy Sidecar

Service Bar

Bar Container

Out-of-band telemetry propagation

telemetry

reports

Control flow

application traffic

Application traffic

application namespace

telemetry reports

Istio Architecture

@lcalcote

Galley

Ingress Gateway

Egress Gateway

Control Plane

Data Plane

octa-system namespace

policy check

Foo Pod

Proxy
Sidecar

Service Foo

discovery & config

Foo Container

Bar Pod

Service Bar

Bar Container

Out-of-band telemetry propagation

telemetry

reports

Control flow

application traffic

Application traffic

application namespace

telemetry reports

Octarine Architecture

@lcalcote

Policy
Engine

Security Engine

Visibility
Engine

Proxy
Sidecar

Control Plane

Data Plane

linkerd-system namespace

Foo Pod

Proxy Sidecar

Service Foo

Foo Container

Bar Pod

Proxy Sidecar

Service Bar

Bar Container

Out-of-band telemetry propagation

telemetry

scarping

Control flow during request processing

application traffic

Application traffic

application namespace

telemetry scraping

@lcalcote

Architecture

destination

Prometheus

Grafana

tap

web

CLI

proxy-api

public-api

Linkerd

proxy-injector

Control Plane

Data Plane

Foo Pod

Proxy Sidecar

Service Foo

Foo Container

Bar Pod

Proxy Sidecar

Service Bar

Bar Container

Out-of-band telemetry propagation

telemetry

scarping

Control flow during request processing

application traffic

Application traffic

application namespace

telemetry scraping

@lcalcote

Architecture

destination

Prometheus

Grafana

NSMe

domain

client

proxy-api

public-api

Network
Service
Mesh

proxy-injector

let's wait until after NSMCon

Service Mesh Deployment Models

Client

Edge Cache

Istio Gateway

(envoy)

Cache Generator

Collection of VMs running APIs

service mesh

Istio VirtualService

Istio ServiceEntry

Situation:

existing services running on VMs (that have little to no service-to-service traffic).
nearly all traffic flows from client to the service and back to client.

Benefits:

gain granular traffic control (e.g path rewrites).
detailed service monitoring without immediately deploying a thousand sidecars.

Ingress

Istio - The Weather Company's Journey

Out-of-band telemetry propagation

Application traffic

@lcalcote

Control flow

Proxy per Node

Service A

linkerd

Node (server)

Service A

Service B

linkerd

Node (server)

Service A

Service C

linkerd

Node (server)

Advantages:

Less (memory) overhead.
Simpler distribution of configuration information.
primarily physical or virtual server based; good for large monolithic applications.

Disadvantages:

Coarse support for encryption of service-to-service communication, instead host-to-host encryption and authentication policies.
Blast radius of a proxy failure includes all applications on the node, which is essentially equivalent to losing the node itself.
Not a transparent entity, services must be aware of its existence.

layer5.io/books

Advantages:

Good starting point for building a brand-new microservices architecture or for migrating from a monolith.

Disadvantages:

When the number of services increase, it becomes difficult to manage.

Router "Mesh"

Fabric Model

Advantages:

Granular encryption of service-to-service communication.
Can be gradually added to an existing cluster without central coordination.

Disadvantages:

Lack of central coordination. Difficult to scale operationally.

Ingress or Edge Proxy

Advantages:

Works with existing services that can be broken down over time.

Disadvantages:

Is missing the benefits of service-to-service visibility and control.

@layer5

layer5.io/landscape

Service Mesh Abstractions

layer5.io/blog/a-standard-interface-for-service-meshes

Service Mesh Interface (SMI)

Multi-Vendor Service Mesh Interoperation

Hamlet

@lcalcote

Adopter’s Dilemma

Which service mesh to use?

What's the catch? Nothing's for free.

Playground

WHICH SERVICE MESH SHOULD I USE AND HOW DO I GET STARTED?

Learn about the functionality of different service meshes and visually manipulate mesh configuration.

Performance Benchmark

WHAT OVERHEAD DOES BEING ON THE SERVICE MESH INCUR?

Benchmark the performance of your application across different service meshes and compare their overhead.

layer5.io/meshery

@lcalcote

Configuration

Security

Telemetry

Control Plane

Data
Plane

service mesh ns

Foo Pod

Proxy Sidecar

Service Foo

Foo Container

Bar Pod

Proxy Sidecar

Service Bar

Bar Container

Out-of-band telemetry propagation

Control flow

application traffic

http / gRPC

Application traffic

application namespace

Meshery Architecture

@lcalcote

Ingress Gateway

Egress Gateway

Management
Plane

meshery

adapter

gRPC

kube-api

kube-system

Service Mesh Abstractions

layer5.io/blog/a-standard-interface-for-service-meshes