Service mesh concept in Microservices - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a service mesh in microservices architecture?

A service mesh is a dedicated layer that manages communication between microservices. It helps with routing, security, and monitoring without changing the microservices themselves.

beginner

Name two common features provided by a service mesh.

Two common features are traffic management (like load balancing and routing) and security (like encryption and authentication between services).

intermediate

How does a service mesh improve security between microservices?

It encrypts communication between services and enforces policies like authentication and authorization automatically.

intermediate

What role do sidecar proxies play in a service mesh?

Sidecar proxies run alongside each microservice instance to handle communication tasks like routing, retries, and security, without changing the service code.

beginner

Give an example of a popular service mesh technology.

Istio is a popular service mesh that provides traffic management, security, and observability for microservices.

What is the main purpose of a service mesh?

A To replace microservices with monoliths

B To store data for microservices

C To build user interfaces

D To manage communication between microservices

A service mesh manages communication between microservices, handling routing, security, and monitoring.

Which component usually runs alongside each microservice in a service mesh?

A Sidecar proxy

B Database

C Load balancer

D API gateway

Sidecar proxies run alongside microservices to manage communication tasks.

How does a service mesh enhance security?

A By removing firewalls

B By storing passwords in plain text

C By encrypting service-to-service communication

D By disabling authentication

Service meshes encrypt communication and enforce authentication to improve security.

Which of these is a popular service mesh tool?

A Istio

B Docker

C Kubernetes

D Jenkins

Istio is a widely used service mesh technology.

What problem does a service mesh solve in microservices?

A Writing frontend code

B Complex communication and security management

C Database schema design

D Hardware provisioning

Service mesh simplifies communication and security between many microservices.

Explain what a service mesh is and why it is useful in microservices.

Think about how microservices talk to each other and what problems a service mesh solves.

Describe the role of sidecar proxies in a service mesh.

Imagine a helper that manages communication tasks for each microservice.

Practice

1. What is the main purpose of a service mesh in microservices architecture?

easy

A. To write application business logic

B. To store data for microservices

C. To replace microservices with monolithic applications

D. To manage communication between microservices securely and reliably

Solution

1. Step 1: Understand the role of service mesh

   A service mesh handles how microservices talk to each other, focusing on communication.

2. Step 2: Identify what service mesh does not do

   It does not store data, replace microservices, or write business logic.

3. Final Answer:

   To manage communication between microservices securely and reliably -> Option D

4. Quick Check:

   Service mesh = communication management [OK]

Hint: Service mesh controls microservice communication, not data or logic [OK]

Common Mistakes:

• Confusing service mesh with data storage
• Thinking service mesh replaces microservices
• Assuming service mesh writes app code

2. Which of the following is a common tool used to implement a service mesh?

easy

A. Docker

B. Istio

C. Kubernetes

D. Git

Solution

1. Step 1: Recall popular service mesh tools

   Istio, Linkerd, and Consul are well-known service mesh tools.

2. Step 2: Differentiate from other tools

   Docker is for containers, Kubernetes for orchestration, Git for version control, not service mesh.

3. Final Answer:

   Istio -> Option B

4. Quick Check:

   Istio = service mesh tool [OK]

Hint: Istio is a popular service mesh tool, not Docker or Git [OK]

Common Mistakes:

• Choosing Docker or Kubernetes as service mesh
• Confusing version control tools with service mesh
• Mixing container tools with service mesh tools

3. Given a microservices setup with Istio service mesh, what happens when a service-to-service call fails due to network issues?

medium

A. Istio retries the call automatically based on configured policies

B. The call fails immediately without retries

C. Istio shuts down the service permanently

D. The service mesh ignores the failure and logs no information

Solution

1. Step 1: Understand Istio's retry feature

   Istio can automatically retry failed calls to improve reliability.

2. Step 2: Eliminate incorrect behaviors

   Istio does not shut down services or ignore failures silently; it logs and manages retries.

3. Final Answer:

   Istio retries the call automatically based on configured policies -> Option A

4. Quick Check:

   Istio retries failed calls = true [OK]

Hint: Istio retries failed calls automatically if configured [OK]

Common Mistakes:

• Assuming no retries happen on failure
• Thinking Istio shuts down services on failure
• Believing failures are ignored silently

4. You deployed a service mesh but notice that traffic between microservices is not encrypted. What is the most likely cause?

medium

A. The network cables are unplugged

B. The microservices are not running

C. Mutual TLS (mTLS) is not enabled in the service mesh configuration

D. The service mesh is not installed

Solution

1. Step 1: Check encryption settings in service mesh

   Service mesh uses mutual TLS (mTLS) to encrypt traffic between services.

2. Step 2: Identify why encryption might fail

   If mTLS is not enabled, traffic remains unencrypted despite service mesh presence.

3. Final Answer:

   Mutual TLS (mTLS) is not enabled in the service mesh configuration -> Option C

4. Quick Check:

   mTLS disabled = no encryption [OK]

Hint: Enable mTLS to encrypt service mesh traffic [OK]

Common Mistakes:

• Assuming services not running causes no encryption
• Thinking service mesh absence causes partial encryption
• Ignoring mTLS setting importance

5. You want to add observability to your microservices without changing their code. How does a service mesh help achieve this?

hard

A. By injecting sidecar proxies that monitor and report traffic metrics transparently

B. By rewriting the microservices code to add logging

C. By replacing microservices with a single monolithic app

D. By disabling network communication between services

Solution

1. Step 1: Understand sidecar proxy role in service mesh

   Service mesh injects sidecar proxies alongside microservices to handle communication and monitoring without code changes.

2. Step 2: Eliminate incorrect options

   Service mesh does not rewrite code, replace microservices, or disable communication.

3. Final Answer:

   By injecting sidecar proxies that monitor and report traffic metrics transparently -> Option A

4. Quick Check:

   Sidecar proxies add observability without code change [OK]

Hint: Sidecar proxies add monitoring without changing app code [OK]

Common Mistakes:

• Thinking code must be rewritten for observability
• Confusing service mesh with app replacement
• Assuming communication is disabled for observability