Consul 1.15 Practice Test 4 — 25 Questions

Question 1

When configuring an ACL policy for cross-datacenter access, what policy rule is necessary to read service information from a remote datacenter?

Accepted Answer

node_prefix "" { policy = "read" }. You need 'service_prefix' or 'node_prefix' policies that explicitly allow reading in the target datacenter.

Answer

service_prefix "*" { policy = "write" }

Answer

agent_prefix "" { policy = "read" }

Answer

acl_prefix "" { policy = "read" }

Question 2

What is the primary role of the Consul Connect 'upstream' configuration?

Accepted Answer

To define the services that a local service can connect to.. Upstreams define the dependencies of a service, allowing the proxy to route to specific services.

Answer

To set intention priority.

Answer

To register external services.

Answer

To define health check ports.

Question 3

Which THREE of the following fields are typically included in a service metadata (meta) block?

Accepted Answer

environment. Meta is used for arbitrary key-value pairs to support application logic.

Answer

kernel_version

Answer

password

Question 4

What is the recommended number of Consul servers per datacenter to ensure high availability?

Accepted Answer

3. The recommended number for a consensus-based system like Consul is 3 or 5, to tolerate n/2-1 failures.

Answer

2

Answer

1

Answer

10

Question 5

You have a service that requires specific routing logic based on the environment. How can you distinguish between 'production' and 'staging' instances of the same service name using metadata?

Accepted Answer

Apply 'production' or 'staging' tags to the service definition.. Service tags are the standard way to categorize and filter services within the Consul catalog.

Answer

Use different service names for every environment.

Answer

Modify the service's port number.

Answer

Assign different Consul datacenters.

Question 6

Which file format is primarily used for defining services in Consul?

Accepted Answer

JSON. Consul supports JSON or HCL.

Answer

YAML

Answer

TOML

Answer

XML

Question 7

Which THREE items are included in the metadata shared via WAN gossip?

Accepted Answer

Datacenter identification.. WAN gossip shares node membership, datacenter association, and health status for the server nodes.

Answer

The full list of local service definitions.

Answer

The local KV store contents.

Question 8

You are configuring a service check that needs to be ignored if the node is in maintenance mode. What is the correct approach?

Accepted Answer

Use the 'consul maintenance' command on the node.. Maintenance mode stops health checks from affecting the service's passing/failing status.

Answer

Use a tag named 'maintenance'.

Answer

Set 'maintenance_mode' to true in the service definition.

Answer

Set the 'status' to 'maintenance' in the API.

Question 9

When multiple agents are in a cluster, how does Consul ensure that service discovery information is consistent across all nodes?

Accepted Answer

Via the Raft consensus protocol for catalog changes.. The Gossip Protocol (serf) and Raft consensus maintain state across nodes.

Answer

Using a centralized database like PostgreSQL.

Answer

By polling the leader every second.

Answer

By broadcasting all service updates to every node.

Question 10

Which TWO of the following are standard DNS records returned by Consul for service discovery?

Accepted Answer

SRV. Consul uses SRV and A records for service resolution.

Answer

NS

Answer

SOA

Answer

PTR

Question 11

You need to verify if a node has successfully joined the cluster for service discovery. Which tool confirms this?

Accepted Answer

consul members. 'consul members' lists the nodes in the cluster.

Answer

consul catalog nodes

Answer

consul info

Answer

consul services

Question 12

Which TWO of the following are benefits of using Consul Connect?

Accepted Answer

Centralized authorization policies.. Consul Connect simplifies mTLS management and provides secure service-to-service authorization.

Answer

Increased application latency.

Answer

Elimination of firewalls.

Answer

Automatic database replication.

Question 13

You are querying the Consul DNS interface for a service. How can you exclude specific tags from the results?

Accepted Answer

Consul DNS does not support tag exclusion; you must filter via the HTTP API.. Consul DNS queries do not support tag exclusion directly in the query string; you filter by including only the desired tags.

Answer

Use the '!' character before the tag name.

Answer

Add a 'not' parameter to the query.

Answer

Use regex in the service name.

Question 14

You need to perform a canary deployment for a service. What Consul feature should you use?

Accepted Answer

Service splitting via Service Resolver.. Consul's service resolver and router resources allow for traffic splitting between different service subsets.

Answer

KV store manual updates.

Answer

Intentions.

Answer

Service mesh gateway.

Question 15

Which TWO of the following are true regarding the Consul Service Catalog?

Accepted Answer

It provides a unified view of all services in the cluster.. The catalog is replicated via Raft and can be queried via API or DNS.

Answer

It is strictly read-only.

Answer

It is only accessible via the CLI.

Answer

It is stored in the local disk of every agent.

Question 16

You need to deny all traffic between 'service-a' and 'service-b' using intentions. What is the most efficient way to achieve this?

Accepted Answer

consul intention create -deny service-a service-b. Intentions can be set to 'deny' explicitly, which overrides any 'allow' rules.

Answer

consul intention create -allow-none service-a service-b

Answer

consul intention set -action=drop service-a service-b

Answer

consul intention delete service-a service-b

Question 17

Which TWO of the following actions occur when a node fails in a Consul cluster?

Accepted Answer

All services on the node are marked critical.. The node is marked down, and its services are removed from the catalog.

Answer

The node is immediately deleted from the cluster.

Answer

The node is automatically rebooted.

Answer

The entire cluster shuts down.

Question 18

Which THREE of the following are valid check types in Consul?

Accepted Answer

TCP. Consul supports HTTP, TCP, and Script (external) health checks.

Answer

SSH

Answer

FTP

Question 19

Which THREE of the following are benefits of using the Consul DNS interface?

Accepted Answer

No application code changes required.. Ease of use, platform-agnostic, and no application changes are benefits.

Answer

Provides advanced traffic shifting.

Answer

Encrypts all traffic between services.

Question 20

Which component acts as the default sidecar proxy for Consul Connect?

Accepted Answer

Envoy. Envoy is the default and recommended sidecar proxy for Consul Connect.

Answer

Nginx

Answer

HAProxy

Answer

Linkerd