Quiz: Grafana

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3 questions

L0 (1 questions)

1. How do you use Grafana template variables to make dashboards dynamic?

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Variables are defined in Dashboard Settings > Variables. Syntax in queries: $variable or ${variable}. Types: Query (populated from data source, e.g., label_values(up, job)), Custom (static list), Interval (time bucketing). Reference in panel queries like: rate(http_requests_total{job="$job"}[5m]). Multi-value variables use regex: {job=~"$job"} with Include All option.

L1 (2 questions)

1. Grafana dashboard shows 'No data'. What do you check?

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1. Data source connection (Settings > Data Sources > Test).
2. Time range too narrow or in the future.
3. Query syntax errors (run in Explore).
4. Metric name changed or missing labels.

2. A Grafana dashboard shows gaps in metric data. What are the common causes?

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1. Scrape target was down (Prometheus could not reach it).
2. Time range includes periods before the metric existed.
3. Query uses rate() on a counter that reset (shows as gap unless using increase()).
4. Stale markers: target removed, series goes stale after 5 minutes.
5. Step/resolution mismatch: query step larger than scrape interval.
6. Null values: use 'connect null values' panel option to bridge gaps.