3 posts tagged with "SLO"

Third‑party dependencies (auth, payments, CDNs, search, LLM APIs) are indispensable — and opaque. When they wobble, your app can fail in surprising ways: slow fallbacks, retry storms, cache stampedes, and silent feature degradation. The goal is not to eliminate external risk, but to make it visible, bounded, and quickly mitigated.

This post outlines a pragmatic approach to dependency‑aware monitoring and automation you can implement today with Tianji.

Why external failures cascade​

• Latency amplification: upstream 300–800 ms p95 spills into your end‑user p95.
• Retry feedback loops: naive retries multiply load during partial brownouts.
• Hidden coupling: one provider outage impacts multiple features at once.
• Unknown blast radius: you discover the topology only after an incident.

Start with a topology and blast radius view​

Build a simple dependency map: user flows → services → external providers. Tag each edge with SLOs and failure modes (timeouts, 4xx/5xx, quota, throttling). During incidents, this “where can it hurt?” view shortens time‑to‑mitigation.

With Tianji’s Unified Feed, you can fold provider checks, app metrics, and feature events into a single timeline to see impact and causality quickly.

Proactive signals: status pages aren’t enough​

• Poll provider status pages, but don’t trust them as sole truth.
• Add synthetic checks from multiple regions against provider endpoints and critical flows.
• Track error budgets separately for “external” vs “internal” failure classes to avoid masking.
• Record quotas/limits (req/min, tokens/day) as first‑class signals to catch soft failures.

Measure what users feel, not just what providers return​

Provider‑reported 200 OK with 2–3 s latency can still break user flows. Tie provider metrics to user funnels: search → add to cart → pay. Alert on delta between control and affected cohorts.

Incident playbooks for external outages​

Focus on safe, reversible actions:

• Circuit breakers + budgets: open after N failures/latency spikes; decay automatically.
• Retry with jitter and caps; prefer idempotent semantics; collapse duplicate work.
• Progressive degradation: serve cached/last‑known‑good; hide non‑critical features behind flags.
• Traffic shaping: reduce concurrency towards the failing provider to protect your core.

How to ship this with Tianji​

• Unified Feed aggregates checks, metrics, and product events; fold signals by timeline for clear causality. See Feed State Model and Channels.
• Synthetic monitors for external APIs and critical user journeys; multi‑region, cohort‑aware. See Custom Script Monitor.
• Error‑budget tracking per dependency with burn alerts; correlate to user funnels.
• Server Status Reporter to get essential host metrics fast. See Server Status Reporter.
• Website tracking to instrument client‑side failures and measure real user impact. See Telemetry Intro and Website Tracking Script.

Implementation checklist​

• Enumerate external dependencies and map them to user‑visible features and SLOs
• Create synthetic checks per critical API path (auth, pay, search) across regions
• Define dependency‑aware alerting: error rate, P95, quota, throttling, and burn rates
• Add circuit breakers and progressive degradation paths via feature flags
• Maintain a unified incident timeline: signals → mitigations → outcomes; review and codify

Closing​

External dependencies are here to stay. The teams that win treat them as part of their system: measured, bounded, and automated. With Tianji’s dependency‑aware monitoring and unified timeline, you can turn opaque third‑party risk into fast, confident incident response.

Most monitoring setups work fine in steady state, yet fall apart during releases: thresholds misfire, samples miss the key moments, and alert storms hide real issues. Release‑aware monitoring brings “release context” into monitoring decisions—adjusting sampling/thresholds across pre‑, during‑, and post‑deploy phases, folding related signals, and focusing on what truly impacts SLOs.

Why “release‑aware” matters​

• Deploys are high‑risk windows with parameter, topology, and traffic changes.
• Static thresholds (e.g., fixed P95) produce high false‑positive rates during rollouts.
• Canary/blue‑green needs cohort‑aware dashboards and alerting strategies.

The goal: inject “just released?”, “traffic split”, “feature flags”, and “target cohorts” into alerting and sampling logic to increase sensitivity where it matters and suppress noise elsewhere.

What release context includes​

• Commits/tickets: commit, PR, ticket, version
• Deploy metadata: start/end time, environment, batch, blast radius
• Traffic strategy: canary ratio, blue‑green switch, rollback points
• Feature flags: on/off, cohort targeting, dependent flags
• SLO context: error‑budget burn, critical paths, recent incidents

A practical pre‑/during‑/post‑deploy policy​

Before deploy (prepare)​

• Temporarily raise sampling for critical paths to increase metric resolution.
• Switch thresholds to “release‑phase curves” to reduce noise from short spikes.
• Pre‑warm runbooks: prepare diagnostics (dependency health, slow queries, hot keys, thread stacks).

During deploy (canary/blue‑green)​

• Fire strong alerts only on “canary cohort” SLO funnels; compare “control vs canary.”
• At traffic shift points, temporarily raise sampling and log levels to capture root causes.
• Define guard conditions (error rate↑, P95↑, success↓, funnel conversion↓) to auto‑rollback or degrade.

After deploy (observe and converge)​

• Gradually return to steady‑state sampling/thresholds; keep short‑term focus on critical paths.
• Fold “release events + metrics + alerts + actions” into one timeline for review and learning.

Incident folding and timeline: stop alert storms​

• Fold multi‑source signals of the same root cause (DB jitter → API 5xx → frontend errors) into a single incident.
• Attach release context (version, traffic split, feature flags) to the incident for one‑view investigation.
• Record diagnostics and repair actions on the same timeline for replay and continuous improvement.

Ship it with Tianji​

• Unified Feed aggregates checks, metrics, and events; fold by timeline: see Feed State Model and Channels.
• Lightweight server status reporting: get key host metrics in minutes: see Server Status Reporter.
• Open telemetry: product/app events capture release context: see Telemetry Intro and Website Tracking Script.
• Custom monitors and synthetic flows on critical paths with policy‑based sampling and automated actions: see Custom Script Monitor.

Implementation checklist​

• Map critical paths and SLOs; define “release‑phase thresholds/sampling” and guard conditions
• Ingest release context (version, traffic split, flags, cohorts) as labels on events/metrics
• Build “canary vs control” dashboards and delta‑based alerts
• Auto bump sampling/log levels at shift/rollback points, then decay to steady state
• Keep a unified timeline of “signals → actions → outcomes”; review after each release and codify into runbooks

Closing​

Release‑aware monitoring is not “more dashboards and alerts,” but making “releases” first‑class in monitoring and automation. With Tianji’s unified timeline and open telemetry, you can surface issues earlier, converge faster, and keep human effort focused on real judgment and trade‑offs.

Cloud costs are rising, data volumes keep growing, and yet stakeholders expect faster incident response with higher reliability. The answer is not “more data” but the right data at the right price. Cost-aware observability helps you preserve signals that protect user experience while removing expensive noise.

This guide shows how to re-think telemetry collection, storage, and alerting so you can keep your SLOs intact—without burning your budget.

Why Cost-Aware Observability Matters​

Traditional monitoring stacks grew by accretion: another exporter here, a new trace sampler there, duplicated logs everywhere. The result is ballooning ingest and storage costs, slow queries, and alert fatigue. A cost-aware approach prioritizes:

• Mission-critical signals tied to user outcomes (SLOs)
• Economic efficiency across ingest, storage, and query paths
• Progressive detail: coarse first, deep when needed (on-demand)
• Tool consolidation and data ownership to avoid vendor lock-in

Principles to Guide Decisions​

1. Minimize before you optimize: remove duplicated and low-value streams first.
2. Tie signals to SLOs: if a metric or alert cannot impact a decision, reconsider it.
3. Prefer structured events over verbose logs for business and product telemetry.
4. Use adaptive sampling: full fidelity when failing, economical during steady state.
5. Keep raw where it’s cheap, index where it’s valuable.

Practical Tactics That Save Money (Without Losing Signals)​

1) Right-size logging​

• Convert repetitive text logs to structured events with bounded cardinality.
• Drop high-chattiness DEBUG in production by default; enable targeted DEBUG windows when investigating.
• Use log levels to route storage: “hot” for incidents, “warm” for audits, “cold” for long-term.

2) Adaptive trace sampling​

• Keep 100% sampling on error paths, retries, and SLO-adjacent routes.
• Reduce sampling for healthy, high-volume endpoints; increase on anomaly detection.
• Elevate sampling automatically when deploys happen or SLO burn accelerates.

3) Metrics with budgets​

• Prefer low-cardinality service-level metrics (availability, latency P95/P99, error rate).
• Add usage caps per namespace or team to prevent runaway time-series.
• Promote derived, decision-driving metrics to dashboards; demote vanity metrics.

4) Event-first product telemetry​

• Track business outcomes with compact events (e.g., signup_succeeded, api_call_ok).
• Enrich events once at ingest; avoid re-parsing massive log lines later.
• Use event retention tiers that match analysis windows (e.g., 90 days for product analytics).

A Cost-Efficient Observability Architecture​

A practical pattern:

• Edge ingestion with lightweight filters (drop obvious noise early)
• Split paths: metrics → time-series DB; traces → sampled store; events → columnar store
• Cold object storage for raw, cheap retention; hot indices for incident triage
• Query federation so responders see a single timeline across signals

This architecture supports “zoom in on demand”: start with an incident’s SLO breach, then progressively load traces, logs, and events only when necessary.

Budget Policies and Alerting That Respect Humans (and Wallets)​

Policy	Example	Outcome
Usage guardrails	Each team gets a monthly metric-cardinality quota	Predictable spend; fewer accidental explosions
SLO-driven paging	Page only on error budget burn and sustained latency breaches	Fewer false pages, faster MTTR
Deploy-aware boosts	Temporarily increase sampling right after releases	High-fidelity data when it matters
Auto-archival	Move logs older than 14 days to cold storage	Large savings with no impact on incidents

Pair these with correlation-based alerting. Collapse cascades (DB down → API 5xx → frontend errors) into a single incident to reduce noise and investigation time.

How Tianji Helps You Do More With Less​

• Unified feed correlates checks, metrics, traces/events in one place: see Feed state model and Channels.
• Lightweight server status with quick setup: server status reporter.
• Flexible, privacy-friendly telemetry for apps and websites: telemetry intro, website tracking script, and events tracking.
• Custom monitors and synthetic flows to protect SLOs with minimal overhead: custom script monitor.

With Tianji, you keep data ownership and can tune which signals to collect, retain, and correlate—without shipping every byte to expensive proprietary backends.

Implementation Checklist​

• Inventory all telemetry producers; remove duplicates and unused streams
• Define SLOs per critical user journey; map signals to decisions
• Set default sampling, then add automatic boosts on deploys and anomalies
• Apply cardinality budgets; alert on budget burn, not just raw spikes
• Route storage by value (hot/warm/cold); add auto-archival policies
• Build correlation rules to collapse cascades into single incidents

Key Takeaways​

1. Cost-aware observability focuses on signals that protect user experience.
2. Use adaptive sampling and storage tiering to control spend without losing fidelity where it matters.
3. Correlate signals into a unified timeline to cut noise and accelerate root-cause analysis.
4. Tianji helps you implement these patterns with open, flexible building blocks you control.