Observability terms
You cannot fix what you cannot see
Running software in production without observability is flying blind. Metrics, logs, traces, dashboards, alerting, and the three pillars of observability give you the insight needed to understand what your system is actually doing under real conditions. This category covers the tools, patterns, and vocabulary of production-grade visibility.
Structured Logging PHP 8.0+
Emitting log entries as machine-parseable key-value pairs (JSON) rather than free-form strings — enabling filtering, aggregation, and alerting.
1mo ago
observability intermediate
Alerting Best Practices
Good alerts are actionable, symptom-based, and rare — page on user impact, not causes. Alert fatigue from noisy alerts is as dangerous as no alerts.
2mo ago
observability intermediate
APM — Application Performance Monitoring PHP 7.0+
APM tools (Datadog, New Relic, Blackfire) automatically instrument applications to profile code-level performance — identifying slow DB queries, N+1 problems, and method-level bottlenecks.
2mo ago
observability intermediate
Canary Deployment & Observability
Canary deployments route a small percentage of traffic to a new version — compare its golden signals against the stable version before full rollout to catch regressions automatically.
2mo ago
observability intermediate
Cardinality in Metrics
Cardinality is the number of unique label value combinations — high cardinality (user_id, URL, session_id as labels) creates millions of time series and crashes Prometheus.
2mo ago
observability intermediate
Cardinality in Observability PHP 7.0+
The number of unique combinations of label values in a metric — high cardinality (millions of unique label combinations) causes memory exhaustion in time-series databases and is the most common observability scaling problem.
2mo ago
observability intermediate
Distributed Tracing
Distributed tracing tracks a request as it flows through multiple services — each service adds a span to a shared trace, giving end-to-end visibility into latency and failures.
2mo ago
observability intermediate
Error Budget
Error budget is the allowed amount of unreliability within an SLO period — 99.9% SLO = 43.8 min/month downtime allowed. When budget is exhausted, reliability takes priority over features.
2mo ago
observability intermediate
Log Aggregation (ELK/Loki)
Log aggregation collects logs from all services into a central searchable store — ELK (Elasticsearch+Logstash+Kibana) for full-text search, Loki (Prometheus-style) for cost-efficient label-based search.
2mo ago
observability intermediate
OpenTelemetry
OpenTelemetry (OTel) is the open standard for telemetry — a vendor-neutral SDK for traces, metrics, and logs that exports to any backend (Jaeger, Datadog, Honeycomb, Prometheus).
2mo ago
observability intermediate
Prometheus Concepts
Prometheus is a pull-based metrics system — services expose /metrics in text format, Prometheus scrapes them, stores as time series, and evaluates alerting rules via PromQL.
2mo ago
observability intermediate
SLO / SLI / SLA
SLI (what you measure), SLO (your internal target), SLA (your customer commitment) — the hierarchy that turns vague 'uptime' promises into measurable operational objectives.
2mo ago
observability intermediate
Trace Sampling Strategies
Sampling records only a fraction of traces to control cost — head-based sampling decides at start, tail-based decides at end (after seeing the full trace), enabling smart error/latency capture.
2mo ago
observability intermediate
Traces & Spans PHP 7.0+
The building blocks of distributed tracing — a trace represents a complete request journey across services, composed of spans that each record one operation with its start time, duration, and parent–child relationship.
2mo ago
observability intermediate
Alert Fatigue
When alerts fire so frequently or for such trivial reasons that on-call engineers begin ignoring them — the most dangerous state for a production monitoring system.
2mo ago
observability intermediate
APM Tools PHP 5.0+
Application Performance Monitoring tools — Datadog, New Relic, Elastic APM — provide distributed tracing, performance profiling, error tracking, and anomaly detection in production.
2mo ago
observability intermediate
Log Levels Best Practices PHP 5.0+
Using the correct severity level — ERROR, WARNING, INFO, DEBUG — ensures alerting triggers on real issues while debug noise stays suppressible in production.
2mo ago
observability intermediate
PHP Observability PHP 8.0+
The three pillars of observability in PHP applications — structured logs, application metrics, and distributed traces — and the tools that provide them (Monolog, Prometheus, OpenTelemetry).
2mo ago
observability intermediate
Uptime Monitoring PHP 5.0+
Continuously checking that your application is reachable and responding correctly — synthetic monitoring (scripted checks from external locations) vs real user monitoring (RUM from actual traffic).
2mo ago
observability intermediate
Metrics Types Counters (ever-increasing), Gauges (current value), Histograms (distribution), and Summaries — each suited to different measurement needs in monitoring systems.
2mo ago
observability intermediate