PCA Observability Concepts Practice Test 3 — 15 Questions

Question 1

What is the primary function of the 'scrape_timeout' configuration?

Accepted Answer

It limits the duration of the HTTP connection.. It defines how long Prometheus waits for a response from the target before considering the scrape a failure.

Answer

It determines how long to keep metrics in memory.

Answer

It sets the interval between scrapes.

Answer

It restricts the size of the metric payload.

Question 2

How does the 'stale marker' work in Prometheus?

Accepted Answer

It prevents the graph from showing data after the target goes down.. When a target stops responding, Prometheus writes a stale marker to the TSDB so that graphs stop at the last known value rather than showing an infinite line or incorrect data.

Answer

It restarts the scrape job.

Answer

It sends an alert.

Answer

It deletes the metric data.

Question 3

If you have a metric `http_requests_total` and want the increase over 5 minutes, what is the best PromQL syntax?

Accepted Answer

increase(http_requests_total[5m]). The `increase()` function is specifically designed to calculate the increase of counter values over a specified range.

Answer

delta(http_requests_total[5m])

Answer

rate(http_requests_total[5m])

Answer

sum(http_requests_total[5m])

Question 4

What is the primary goal of observability?

Accepted Answer

To understand system state from external outputs.. Observability aims to answer 'why' a system is in its current state by understanding its internal state through outputs (metrics, logs, traces).

Answer

To store as many logs as possible.

Answer

To automate code deployments.

Answer

To replace testing.

Question 5

Why are 'logs' essential for debugging, even with perfect metrics?

Accepted Answer

Logs contain detailed context about specific events.. Logs provide the granular, detailed context (like specific error messages or stack traces) that metrics cannot provide.

Answer

Metrics are too slow.

Answer

Logs are free to store.

Answer

Metrics cannot be used for debugging.

Question 6

When evaluating the 'Traffic' golden signal, what is the best metric to watch for a web service?

Accepted Answer

Requests per second.. Request rate (requests per second) is the standard way to measure traffic volume.

Answer

CPU usage percentage.

Answer

HTTP error count.

Answer

Response latency.

Question 7

Which of these is NOT a Golden Signal?

Accepted Answer

Storage. The Four Golden Signals are Latency, Traffic, Errors, and Saturation. 'Storage' is not one of them.

Answer

Latency

Answer

Saturation

Answer

Errors

Question 8

What is the benefit of the 'service discovery' feature in Prometheus?

Accepted Answer

It simplifies management in dynamic environments.. It automatically updates the list of targets to scrape, eliminating manual updates when infrastructure scales.

Answer

It improves query performance.

Answer

It encrypts the data.

Answer

It reduces the storage size.

Question 9

Which THREE items are standard techniques to reduce metric cardinality?

Accepted Answer

Aggregating raw metrics into broader categories.. Dropping labels, aggregating metrics, and limiting metric frequency are standard ways to reduce cardinality.

Answer

Increasing the scrape interval.

Answer

Adding unique IDs to every label.

Question 10

Which TWO of these are potential side effects of high-cardinality metrics?

Accepted Answer

High memory consumption on the Prometheus server.. Memory exhaustion (OOM) and slow query performance are the direct results of high cardinality.

Answer

Reduced CPU usage on target.

Answer

Faster alert evaluation.

Answer

Decreased network bandwidth.

Question 11

Which THREE of these represent the Four Golden Signals?

Accepted Answer

Errors. Latency, Traffic, Errors, and Saturation are the set.

Answer

Memory Usage

Answer

Availability

Question 12

Which TWO of the following are primary components of the Prometheus monitoring architecture?

Accepted Answer

Alertmanager. Prometheus server and Alertmanager are central components; Grafana and exporters are common but auxiliary or distinct tools.

Answer

Fluentd

Answer

Zipkin

Answer

Kibana

Question 13

Which TWO of the following are examples of metric data?

Accepted Answer

Current CPU usage percentage.. CPU percentage and total request count are classic metrics.

Answer

A full database SQL query statement.

Answer

A line of text in an access log file.

Answer

The stack trace of an application error.

Question 14

Which THREE actions are commonly performed during the 'relabeling' phase in Prometheus?

Accepted Answer

Mapping multiple labels into one.. Replacing labels, dropping series, and mapping labels are standard relabeling actions.

Answer

Configuring the storage retention policy.

Answer

Increasing the memory of the Prometheus instance.

Question 15

Which TWO of these are true about the 'Pull' model?

Accepted Answer

Prometheus initiates the scrape request.. Prometheus controls the scrape and can detect target downtime.

Answer

The load on the server is unpredictable.

Answer

Targets must run a push-client.

Answer

It is limited to local metrics.