304 questions total · 5pages · All types, answers revealed
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Page 2What is the primary benefit of using a pull-based model for monitoring?
If the scrape fails, Prometheus immediately knows the target is down.
Why this answer
The pull model allows the monitoring server to detect when a target is down and prevents the target from overwhelming the monitoring system.
Which TWO of the following are true about the node_exporter?
Correct.
Why this answer
Node exporter is designed for *NIX systems and exposes metrics on port 9100.
You are deploying Prometheus in a Kubernetes cluster and need to ensure it discovers pods labeled 'app=frontend'. Which configuration block is required?
kubernetes_sd_configs allows Prometheus to interface with the Kubernetes API for dynamic discovery.
Why this answer
kubernetes_sd_configs is the standard mechanism to discover pods dynamically.
What is the purpose of 'labels' in Prometheus?
Metric name + labels = unique time series.
Why this answer
Labels provide metadata to metrics, allowing for multi-dimensional querying and filtering (e.g., job='web', instance='1.2.3.4').
You need to monitor the duration of database queries. Which metric type is best for calculating quantiles on the server side?
Histograms allow for the calculation of quantiles on the server side via buckets.
Why this answer
Summaries calculate configurable quantiles on the client side, while Histograms require server-side calculations.
Which TWO of the following are benefits of using recording rules?
Complex expressions become a single metric name.
Why this answer
Recording rules improve performance for dashboards and provide pre-computed metrics for alerting.
Which label is used to group alerts in Alertmanager?
group_by determines the labels used to bundle alerts.
Why this answer
The 'group_by' field in the route block determines how alerts are grouped into notifications.
A team wants to visualize metrics from Prometheus in Grafana. What is the standard way to connect these two services?
Adding a data source is the native way Grafana queries Prometheus.
Why this answer
Grafana allows users to add Prometheus as a 'Data Source' by providing the URL of the Prometheus server.
When creating a custom exporter, which component is responsible for scraping the data?
Prometheus pulls metrics from the exporter.
Why this answer
The Prometheus server is responsible for initiating the scrape request to the exporter.
When configuring a custom exporter, how do you provide labels to a metric?
Labels are defined during initialization in most client libraries.
Why this answer
Labels are passed as a dictionary or map when creating the metric object in the client library.
Which of these is NOT a Golden Signal?
Storage is an infrastructure concern, not a service signal.
Why this answer
The Four Golden Signals are Latency, Traffic, Errors, and Saturation. 'Storage' is not one of them.
If you perform 'A / B' where A and B have different sets of labels, what happens?
Without group or matching modifiers, no series will match.
Why this answer
Binary operations require matching labels unless modifiers are used; otherwise, the result is empty.
Which THREE of the following functions can be used with counter metrics to calculate rates or increases? (Choose three)
irate() calculates the instantaneous rate of increase for counters.
Why this answer
Counters can be used with rate(), irate(), and increase() functions (among others like delta() for gauges, though delta is technically for gauges, increase is for counters).
Which TWO of the following statements about PromQL label matchers are correct? (Choose TWO)
Correct. = is exact match.
Why this answer
PromQL supports exact equality (=), negative equality (!=), regular expression matching (=~), and negative regular expression matching (!~).
You notice that recording rules are consuming too much CPU on your Prometheus server. What is the most effective way to reduce the load while keeping data available?
Increasing the interval decreases the frequency of calculations, reducing CPU overhead.
Why this answer
Recording rules are evaluated at the 'evaluation_interval'. Increasing this interval reduces CPU usage by running the queries less frequently.
If you have a scrape_interval of 15s, what is the recommended minimum scrape_timeout?
It is standard practice to set the timeout to a significant fraction of the interval, often 10s for a 15s interval.
Why this answer
The timeout should generally be slightly less than or equal to the scrape_interval, but it must be sufficient to allow the target to respond.
Which THREE conditions cause a scrape to be unsuccessful?
Prevents parsing.
Why this answer
Scrapes fail on network timeout, 404/500 errors, or if the target returns invalid text format.
What happens to your alerts if the Alertmanager configuration file contains a syntax error?
Alertmanager maintains operational stability by not loading broken configs.
Why this answer
If the configuration is invalid, Alertmanager will fail to reload, and it will continue using the last known good configuration.
You are deploying Prometheus in a cluster with highly dynamic ephemeral pods. Which concern is the most significant regarding cardinality?
Unique label combinations create new time series, consuming RAM.
Why this answer
High cardinality arises from labels with high-variance values, which can lead to memory exhaustion in the Prometheus TSDB.
You need to calculate the per-second rate of increase of http_requests_total over a 1-minute window. Why is using a 1-minute range window generally discouraged in production?
Correct. Short windows capture too few data points to produce stable rates.
Why this answer
Prometheus scrapes most targets every 15 seconds. A 1-minute window only contains about 4 data points, making the rate calculation highly sensitive to small scraping jitters.
Which function should be used to smooth out short-term fluctuations in a gauge metric by calculating the rolling average over a 10-minute window?
Correct. avg_over_time computes the average over a range window for gauges.
Why this answer
The avg_over_time() function calculates the average value of all data points in the specified range vector for each time series.
Which TWO factors directly influence the accuracy of quantile calculations when using Prometheus Summary metrics?
The chosen quantiles determine what the client tracks.
Why this answer
Summaries compute quantiles on the client side, and accuracy is determined by the configured quantiles and the sliding time window over which they are calculated.
Which Grafana feature allows you to see data from multiple Prometheus servers on a single panel?
Variables enable users to dynamically switch or select data sources in a panel.
Why this answer
Grafana allows you to define multiple data sources and even mix them within a dashboard, or use a data source proxy.
A system is experiencing high latency. You need to identify if the latency is caused by external dependencies. Which of the Four Golden Signals is most relevant for this discovery?
Latency measures time spent per request.
Why this answer
Latency measures the time it takes to service a request, which directly indicates performance issues in dependencies.
You are joining two vectors where the left vector has labels {job="api", instance="host1"} and the right vector has labels {job="api", region="us-east"}. You use the query 'vector_a + ignoring(instance, region) vector_b'. What does the 'ignoring' modifier do?
'ignoring' drops the specified labels from the matching calculation so that series with different instance or region values can still match on remaining labels.
Why this answer
The 'ignoring' modifier instructs Prometheus to ignore specified labels when conducting vector matching between two vectors.
What is the primary difference between an instant vector and a range vector in PromQL?
Correct. Instant vectors represent a single point in time, range vectors represent a historical window.
Why this answer
Instant vectors contain a single sample per time series for the given timestamp, whereas range vectors contain a set of data points over a time window.
What is the difference between 'count' and 'count_values'?
count_values creates new time series based on value frequency.
Why this answer
count aggregates by number of series, while count_values counts the number of occurrences of each sample value.
Which THREE features are provided by the Prometheus HTTP API?
Core functionality.
Why this answer
The API allows querying data, checking target status, and getting rule info.
You are troubleshooting a query and notice that label_replace is being used. What is the primary function of label_replace(v, dst_label, replacement, src_label, regex)?
Correct. label_replace modifies or creates labels based on regular expression extractions.
Why this answer
The label_replace function matches the regex against the value of src_label, and if it matches, sets dst_label to the replacement string.
When designing a monitoring strategy, why should you avoid monitoring 'everything'?
Efficient monitoring focuses on relevant signals.
Why this answer
Excessive metric collection leads to high storage costs, increased query latency, and signal-to-noise ratio degradation (alert fatigue).
When configuring a dashboard panel, what is the significance of the 'Legend' field?
The legend field transforms raw metric labels into readable strings.
Why this answer
The legend field allows you to customize the labels displayed in the graph tooltip and legend section.
Which Grafana panel type is best for showing a trend of a metric over time?
Time series panels visualize how metrics change over time.
Why this answer
The Time series panel is the standard for plotting metrics over time.
Which metric type would best capture the distribution of request latencies?
Histograms provide bucketed distributions.
Why this answer
A Histogram samples observations (usually request durations) and counts them in configurable buckets, allowing for percentiles.
You are using the blackbox_exporter to monitor an HTTP endpoint. Which module configuration is required to check the HTTP status code?
This module specifically validates HTTP 2xx response codes.
Why this answer
The http_2xx module is the standard configuration for checking that an endpoint returns a successful HTTP status code.
Which THREE of the following are valid set operators in PromQL for combining instant vectors? (Choose THREE)
Correct. 'unless' is the complement set operator.
Why this answer
PromQL supports three set operators: and (intersection), unless (complement), and or (union).
Which function evaluates the predictable linear extrapolation of a gauge metric over time to predict future values?
Correct. predict_linear uses linear regression on a range vector to predict values in the future.
Why this answer
The predict_linear() function predicts the value of a gauge metric 't' seconds into the future based on a range vector using simple linear regression.
Which TWO of the following are valid ways to configure target discovery in Prometheus?
Uses DNS lookups.
Why this answer
Prometheus supports multiple SD mechanisms, including file-based and cloud-native providers.
Which THREE of the following are true about the Prometheus Text Exposition Format?
Correct.
Why this answer
It is line-oriented, supports comments starting with #, and each metric line contains the name, optional labels, and value.
You are monitoring a legacy batch processing job that runs for only 30 seconds once every 24 hours. Which Prometheus component is necessary to collect these metrics?
Pushgateway is designed to temporarily store metrics from short-lived batch jobs until Prometheus scrapes it.
Why this answer
Since the job is short-lived, Prometheus's standard scrape interval will likely miss it. The Pushgateway allows the job to push metrics before exiting.
What is the effect of using a 'Summary' metric with client-side quantiles?
Because quantiles are calculated at the source, they cannot be correctly averaged or merged.
Why this answer
Client-side quantiles are calculated per instance, making it impossible to aggregate them across multiple instances of an application.
What is the primary function of the 'scrape_timeout' configuration?
It is the deadline for the scrape response.
Why this answer
It defines how long Prometheus waits for a response from the target before considering the scrape a failure.
When writing a query with arithmetic operators, how does PromQL handle vector matching when both vectors have the exact same label sets?
Correct. Identical label sets match automatically in one-to-one operations.
Why this answer
By default, PromQL performs a one-to-one match when the label sets of both vectors are identical.
Which THREE components are typically involved in the standard Prometheus instrumentation and scraping process?
Used to instrument the code.
Why this answer
The process involves the application (instrumented via client library), the exporter (or the application itself), and the Prometheus server (the scraper).
Which TWO of the following statements regarding native histograms in Prometheus are correct? (Choose TWO)
Correct. histogram_quantile() supports native histograms seamlessly.
Why this answer
Native histograms store multiple buckets within a single chunk/sample, reducing storage overhead and allowing dynamic bucket resolutions.
When using the 'repeat_interval' in Alertmanager, what does it define?
It controls the frequency of notification reminders.
Why this answer
The repeat_interval defines how long to wait before re-sending a notification for an alert that is still active.
Which component is best suited for long-term storage?
Remote write allows offloading data to long-term storage providers.
Why this answer
Prometheus is not designed for indefinite storage; external remote write storage is needed for long-term retention.
Which THREE of these represent the Four Golden Signals?
A Golden Signal.
Why this answer
Latency, Traffic, Errors, and Saturation are the set.
Which Alertmanager feature would you use to prevent a 'ServiceDown' alert from firing if a 'GlobalNetworkOutage' alert is already active?
Inhibition suppresses alerts based on the existence of another.
Why this answer
Inhibition rules allow one alert to suppress another based on matching labels.
A Histogram has buckets [0.1, 0.5, 1, 5]. A request takes 0.7 seconds. Which buckets will be incremented?
The counter increments for every bucket greater than or equal to the observation.
Why this answer
Histograms are cumulative. A value of 0.7 falls into the 1 and 5 buckets (because 0.7 <= 1 and 0.7 <= 5).
You need to perform a binary operation between two vectors where the left vector has labels {job="api", instance="a"} and the right vector has labels {job="api"}. You want to match them using the job label while retaining the instance label from the left side. Which modifier configuration is correct?
Correct. on(job) matches on job, and group_left(instance) pulls the instance label from the left side.
Why this answer
To match on a subset of labels while retaining extra labels on the left side during a one-to-many or many-to-one operation, group_left must be used with the on modifier.
Which of the following selectors matches metric names that start with 'http_'?
Using the internal '__name__' label with the '=~' regex operator matches metric names starting with 'http_'.
Why this answer
The regex matcher '=~' is used with regular expressions, and '^' anchors the match to the beginning of the string.
You need to track the number of requests received by your application. Which metric type should you choose?
Counters are designed for monotonically increasing values like request counts.
Why this answer
A counter is a cumulative metric that represents a single monotonically increasing counter whose value can only increase or be reset to zero on restart.
When performing vector matching between two vectors of different cardinalities, which THREE vector matching modifiers can be used? (Choose three)
'on' restricts which labels are used for matching.
Why this answer
PromQL vector matching modifiers include on, ignoring, group_left, and group_right.
Which THREE of the following are standard ways to handle Prometheus metrics?
Correct.
Why this answer
Common methods include using official client libraries, using exporters, and the textfile collector.
Which THREE of the following metrics are automatically added to all scraped targets?
Indicates scrape success.
Why this answer
Prometheus adds specific metadata labels such as up, scrape_duration, and scrape_samples_scraped.
When configuring Alertmanager 'group_by' settings, what happens if you include a label that is not present on an incoming alert?
Alerts with missing grouping labels are grouped together in a default bucket.
Why this answer
Alertmanager groups alerts based on the defined labels. If a label is missing, the alert is still processed, but it will fall into a 'null' or 'none' bucket for that specific grouping key.
A Prometheus selector includes a negative regex match for environment names: 'environment!="staging"'. Which selector operator achieves this using regular expressions instead of exact matching?
The '!~' operator performs a negative regular expression match.
Why this answer
The '!=' operator is for exact inequality, while '!~' is the negative regular expression match operator in PromQL.
When writing a custom exporter in Python, what is the most common way to expose the metrics?
This is the idiomatic way to expose metrics in the Python library.
Why this answer
The prometheus_client library provides a start_http_server() method to expose metrics on a specified port.
Which of these is considered a 'counter' in Prometheus?
This is a classic counter.
Why this answer
A counter is a cumulative metric that only ever goes up, used for things like request totals.
Which TWO are true about Prometheus alerting rules?
Rules are PromQL expressions.
Why this answer
Alerts are evaluated on the server, and they use PromQL for condition checking.
You have a global Alertmanager configuration where you want to suppress 'DiskSpaceLow' alerts if 'InstanceDown' is active for the same host. Which mechanism accomplishes this?
Inhibit_rules match labels between a source alert and a target alert to suppress the latter.
Why this answer
Inhibition rules in Alertmanager are designed to silence alerts based on labels that match between the firing alert and the inhibited alert.
Which of the following is a correct unit suffix for Prometheus metrics?
Units like _seconds or _bytes are recommended.
Why this answer
Prometheus recommends using base units (e.g., seconds for duration, bytes for memory) and appending the unit to the name.
You are seeing 'Too many active series' in your Prometheus logs. Which action should be your first priority to address this?
This helps isolate the source of high cardinality.
Why this answer
Identifying which labels are causing the high cardinality is the standard first step to prevent OOM (Out Of Memory) crashes.
Why might you use an 'exporter' in Prometheus?
Exporters perform the necessary translation.
Why this answer
Exporters are used to convert metrics from systems that don't natively expose Prometheus format into something Prometheus can scrape.
Where do you define the threshold for a Prometheus alerting rule?
The query expression contains the threshold logic.
Why this answer
The threshold is part of the PromQL query expression within the 'expr' field of the alerting rule.
A legacy batch job runs once per day and finishes in seconds. Why is a standard Prometheus pull model inadequate here?
Pulling requires the target to be available when the scrape occurs.
Why this answer
Prometheus pull intervals are typically set to seconds or minutes; a job that finishes quickly might never be 'up' when Prometheus scrapes it.
You are joining an instant vector of application versions with an instant vector of metrics using a many-to-one relationship. The application version vector has more labels than the metric vector. Which keyword must be appended to the matching modifier to include labels from the 'many' side?
Correct. group_left allows labels from the 'many' side to be included in the result.
Why this answer
In many-to-one or one-to-many matches, group_left or group_right must be provided to specify which side supplies additional labels.
You want to notify different teams based on the 'service' label of an alert. Where should you configure this logic?
Routing logic is defined in the Alertmanager config file.
Why this answer
The Alertmanager configuration file contains the routing tree that maps alerts to receivers based on labels.
Which THREE of the following are key design considerations when creating a custom exporter?
Correct.
Why this answer
Key factors include avoiding high cardinality, ensuring the metrics are exposed via HTTP, and keeping performance overhead low.
Which TWO of the following are primary components of the Prometheus monitoring architecture?
The core alert handler.
Why this answer
Prometheus server and Alertmanager are central components; Grafana and exporters are common but auxiliary or distinct tools.
You are monitoring a Linux server and need to track CPU usage. Which exporter is the standard choice for exposing hardware and OS metrics?
node_exporter provides comprehensive hardware and OS metrics.
Why this answer
node_exporter is the standard Prometheus exporter for hardware and OS metrics exposed by *NIX kernels.
Which of the following describes the 'pull' model's benefit regarding service discovery?
Prometheus finds the targets.
Why this answer
Prometheus can dynamically discover targets (via Kubernetes API, Consul, etc.) and automatically start scraping, removing the need to register every new pod.
Which TWO of the following are true about the Gauge metric type?
Correct.
Why this answer
Gauges allow values to fluctuate and are often used for memory, CPU, or queue length.
Which TWO of the following are valid fields in a Prometheus alerting rule definition?
Mandatory query expression.
Why this answer
A rule must have an 'alert' name and an 'expr' query.
Which TWO of the following are valid data types returned by PromQL queries? (Choose two)
A range vector is a fundamental PromQL result type containing a set of data points over a time range for each time series.
Why this answer
PromQL queries evaluate to one of four types: instant vector, range vector, scalar, or string.
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Page 2Practice PCA by domain
Target a specific domain to shore up weak areas.