Observability & Logging Flashcards
7 cards from real SRE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Observability & Logging flashcards as text
What is 'synthetic monitoring' in the context of SRE observability?
Answer: Simulating user transactions against production or staging to proactively detect availability issues
Synthetic monitoring uses scripted probes or transactions to continuously test service availability and performance from an external perspective.
Which logging anti-pattern causes the most problems during high-severity incidents?
Answer: Logging at DEBUG level in production, causing I/O saturation under load
Verbose DEBUG logging in production can saturate disk I/O and CPU under load, worsening incidents while making logs harder to search.
In SRE, what is the purpose of 'USE method' metrics?
Answer: Measuring Utilization, Saturation, and Errors for every resource in the system
The USE method (Utilization, Saturation, Errors) is a framework for analyzing resource bottlenecks at the infrastructure layer.
What is a 'dead man's switch' alert in SRE observability?
Answer: An alert that fires when a heartbeat or watchdog signal stops being received, indicating a silent failure
A dead man's switch alert fires when an expected periodic signal (heartbeat) is absent, detecting silent failures where nothing is logged.
Which of the following is a key advantage of using a centralized tracing backend like Jaeger or Zipkin?
Answer: It provides a UI to visualize end-to-end request flows and identify latency bottlenecks across services
Centralized tracing backends store and visualize span data, enabling SREs to see the full request path and identify which service contributes most latency.
When building an observability strategy for a new microservice, which action should an SRE prioritize first?
Answer: Defining SLIs and ensuring the service emits the metrics needed to measure them
SLIs define what matters to users, so instrumenting those signals first ensures observability is aligned with reliability goals from day one.
A team uses Elasticsearch, Logstash, and Kibana (ELK stack). What is Logstash's role?
Answer: Ingesting, transforming, and shipping log data to Elasticsearch
Logstash is the data processing pipeline that ingests logs from various sources, applies filters and transformations, and forwards them to Elasticsearch.