Learn vocabulary for service registries, client-side and server-side discovery, health checks, deregistration, and service mesh concepts.
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What is a service registry in microservices vocabulary?
A service registry (e.g., Consul, Eureka, etcd) is the source of truth for service instance locations. Instances self-register on startup with their IP, port, health check URL, and metadata. Clients query the registry to discover available instances. In dynamic environments (containers, auto-scaling), IP addresses change constantly — the registry tracks this automatically.
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What is 'client-side discovery' in microservices vocabulary?
Client-side discovery (Netflix Ribbon pattern): the caller queries the registry (e.g., Eureka), receives a list of healthy instances, applies a load-balancing algorithm (round-robin, least-connections), and calls the chosen instance directly. Advantage: the client controls routing logic. Disadvantage: each client must implement discovery and load-balancing code.
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What is 'server-side discovery' in microservices vocabulary?
Server-side discovery (e.g., AWS ALB + ECS, Kubernetes kube-proxy): the client calls a well-known router endpoint. The router queries the service registry and forwards the request to a healthy instance. The client is decoupled from discovery complexity — it just calls one stable address. Kubernetes Services implement server-side discovery via virtual IP and iptables rules.
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What is the purpose of a 'health check endpoint' in service discovery vocabulary?
Health check endpoints (e.g., GET /health or /actuator/health) return 200 OK when the instance is ready to serve traffic and a non-200 code (or timeout) when it is not. The service registry polls this endpoint at a configured interval. If an instance fails health checks consecutively, it is marked unhealthy and removed from the pool — clients won't receive its address until it recovers.
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What distinguishes a service mesh from a service registry in microservices vocabulary?
Service registry (Consul, Eureka): stores where services are. Service mesh (Istio, Linkerd, Consul Connect): a network layer built from sidecar proxies that handles discovery, routing, mTLS encryption, retries, circuit breaking, and distributed tracing — all transparently. A service mesh often uses a service registry internally but adds rich traffic management on top.
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Sarah from the DevOps team just posted this comment on your PR describing the new user authentication service:
"The service is now registered with Consul. We've configured health checks to monitor its availability. Ensure all dependent services can resolve the service name and that the health check endpoint returns 200 OK."
This comment correctly identifies the use of a service registry (like Consul) for dynamic service location. Health checks are vital because they allow the system to automatically detect and react to unhealthy instances of the service, ensuring high availability. The options that suggest manual DNS configuration or bypassing the registry indicate misunderstandings about the core principles of microservices architecture.
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John from the backend team sent this Slack message during a standup:
'We're using Kubernetes DNS to dynamically resolve service names. It's acting like a service registry, automatically updating our pods when we deploy new versions of OrderService.' What is Kubernetes DNS primarily responsible for in the context of microservices architecture?
Kubernetes DNS plays a crucial role in service discovery by translating service names into IP addresses within the cluster. This eliminates the need for manually configuring service locations and allows services to automatically update when their IPs change during deployments – this is core to dynamic resolution. Option A describes auditing; option C refers to network policies, and option D relates to API key management.
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Maria left this comment on a code review for the new payment processing service:
'I've implemented a health check endpoint that exposes the service's status. This allows the Service Mesh to route traffic only to healthy instances, ensuring high availability.' What is the primary function of a health check endpoint in service discovery?
A health check endpoint is specifically designed to assess a microservice's health – whether it's running correctly and able to handle requests. It sends periodic probes that the service must respond to; if it fails these checks, it indicates an unhealthy state. Options A, B and C describe other functionalities like authentication or logging.
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David is drafting a PR description for the deployment of the new user profile service:
'We've registered this service with Consul and configured it to publish its location using DNS. This enables other services to find and communicate with it.' What does 'publishing its location using DNS' mean in relation to service discovery?
'Publishing its location using DNS' means the service is registering itself within a DNS system (like Consul). This effectively creates a DNS record that maps the service's name to its IP address or hostname. Other services can then query this DNS record to find the service and establish communication – this is server-side discovery.
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You are troubleshooting connectivity issues between two microservices in a distributed system. You discover that one service isn't responding to health check requests. Which of the following is MOST likely the underlying cause?
While all options could contribute to connectivity issues, a service overloaded and unable to process health checks is the most common reason. If the health check endpoint returns an error, or if the registry configuration is wrong, it would prevent resolution entirely. High latency *could* cause failure, but isn't the root cause of the probe failing.
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Emily from the architecture team is explaining the differences between a service mesh and a service registry:
'A service registry maintains a list of available services. A service mesh manages the communication *between* those services – handling things like routing, security, and observability.' What is the primary distinction in their roles?
The key difference lies in their focus: a *service registry* primarily stores metadata about services (like names and locations), whereas a *service mesh* actively manages the communication channels between those services – handling routing, security policies, and observability. Option A is incorrect because security is handled by the service mesh; option C describes availability but doesn't capture the core distinction.
What will I practise in "Service Discovery — Microservices Vocabulary"?
This module focuses on Microservices Language — real workplace phrasing you'll use on the job. It contains 11 scenario-based multiple-choice questions with instant feedback.
Is this exercise free to use?
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How many questions does this exercise have?
This module includes 11 questions. Each one gives an immediate right/wrong result plus a full explanation of the correct phrasing.
What happens if I answer a question incorrectly?
You'll see the correct answer highlighted straight away, along with a plain-English explanation of why it's right and why the other options don't fit — mistakes are part of the learning here.
Can I retry the exercise if I want a better score?
Yes — use the 'Try again' button on the results screen to reset your score and go through the questions again. There's no limit on attempts.
Who is this Microservices Language exercise for?
It's aimed at IT professionals with working English who want to sound more natural and precise around microservices language — useful whether you're preparing for real conversations at work or just building confidence with the vocabulary.
Do I need an account to track my progress?
No account is needed. Your progress through the exercise is tracked locally in your browser for the current session, and you can replay the module at any time.
How is this different from reading a blog article?
This exercise is an interactive drill that tests and reinforces specific phrasing through multiple-choice questions with instant feedback, while blog articles explain concepts and vocabulary in prose. The two work well together.
Where can I find more Microservices Language exercises?
See the Microservices Language hub for more modules like this one, or browse the full Exercises page for other IT-English topics.
Can I complete this exercise on my phone?
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