SRE Observability & Logging 4 — Questions and Answers
Question 1: Which of the following best describes 'RED' method metrics in SRE observability?
- Reliability, Efficiency, Durability
- Rate, Errors, Duration (Correct answer)
- Requests, Events, Delays
- Response, Error, Dependency
Correct answer: Rate, Errors, Duration
The RED method focuses on Rate (requests per second), Errors (failed requests), and Duration (distribution of request latencies) for services.
Question 2: What distinguishes a 'push' model from a 'pull' model in metrics collection?
- In push, the monitoring system scrapes targets; in pull, services send metrics to the collector
- In push, services send metrics to the collector; in pull, the collector scrapes targets (Correct answer)
- Push models use UDP; pull models use TCP
- Push stores data locally; pull stores data remotely
Correct answer: In push, services send metrics to the collector; in pull, the collector scrapes targets
In a push model, applications actively send metrics to a backend (e.g., StatsD, InfluxDB), while in a pull model, the backend scrapes endpoints (e.g., Prometheus).
Question 3: A service emits logs with a correlation ID. What is the primary benefit of including this ID?
- It enables log compression by deduplicating repeated messages
- It allows logs from different services handling the same request to be linked together (Correct answer)
- It encrypts log content for compliance
- It replaces the need for distributed tracing
Correct answer: It allows logs from different services handling the same request to be linked together
A correlation ID ties together all log entries across services for a single request, enabling end-to-end request tracing through logs.
Question 4: Which OpenTelemetry component is responsible for receiving, processing, and exporting telemetry data?
- SDK
- Collector (Correct answer)
- Instrumentation library
- Propagator
Correct answer: Collector
The OpenTelemetry Collector receives telemetry from SDKs, applies processing pipelines, and exports to backends like Jaeger, Prometheus, or Elastic.
Question 5: In log management, what is a 'retention policy' and why is it important for SRE?
- A rule that converts logs from JSON to plain text after 7 days
- A configuration that defines how long logs are stored before deletion, balancing cost and compliance (Correct answer)
- A setting that controls log verbosity in production
- A policy that routes logs to different storage tiers based on severity
Correct answer: A configuration that defines how long logs are stored before deletion, balancing cost and compliance
Retention policies define storage duration for logs, balancing the cost of storage against compliance requirements and incident investigation needs.
Question 6: What problem does 'log rotation' solve in host-based logging?
- It ensures logs are written in structured JSON format
- It prevents log files from growing indefinitely and consuming all disk space (Correct answer)
- It replicates logs across multiple hosts for redundancy
- It parses logs in real time for alerting
Correct answer: It prevents log files from growing indefinitely and consuming all disk space
Log rotation periodically archives or deletes old log files to prevent unbounded disk consumption on the host.
Question 7: An SRE team wants to alert when p99 latency exceeds an SLO threshold. Which metric type should they instrument?
- Counter
- Gauge
- Histogram or Summary (Correct answer)
- Boolean metric
Correct answer: Histogram or Summary
Histograms and Summaries capture latency distributions, enabling percentile calculations like p99 needed for SLO-based alerting.
SRE Observability & Logging 4
Which of the following best describes 'RED' method metrics in SRE observability?