Arquitetura software

Observabilidade

Observabilidade e a capacidade de entender o estado interno de um sistema atraves de suas saidas. Os tres pilares sao: Metricas, Logs e Traces.

Os Tres Pilares

Pilar	O que mede	Ferramenta
Metricas	Dados numericos ao longo do tempo	Prometheus, Grafana
Logs	Eventos e mensagens	ELK Stack, Loki
Traces	Fluxo de requisicoes	Jaeger, Zipkin

Prometheus

Sistema de monitoramento e alertas baseado em metricas.

Configuracao Basica

# prometheus.yml
global:
  scrape_interval: 15s
  evaluation_interval: 15s

alerting:
  alertmanagers:
    - static_configs:
        - targets:
          - alertmanager:9093

rule_files:
  - "alerts/*.yml"

scrape_configs:
  - job_name: 'prometheus'
    static_configs:
      - targets: ['localhost:9090']

  - job_name: 'node-exporter'
    static_configs:
      - targets: ['node-exporter:9100']

  - job_name: 'kubernetes-pods'
    kubernetes_sd_configs:
      - role: pod
    relabel_configs:
      - source_labels: [__meta_kubernetes_pod_annotation_prometheus_io_scrape]
        action: keep
        regex: true

Queries PromQL

# Taxa de requisicoes por segundo
rate(http_requests_total[5m])

# Latencia p99
histogram_quantile(0.99, rate(http_request_duration_seconds_bucket[5m]))

# Uso de CPU
100 - (avg by(instance) (irate(node_cpu_seconds_total{mode="idle"}[5m])) * 100)

# Memoria disponivel
node_memory_MemAvailable_bytes / node_memory_MemTotal_bytes * 100

# Requisicoes com erro
sum(rate(http_requests_total{status=~"5.."}[5m])) / sum(rate(http_requests_total[5m])) * 100

Alertas

# alerts/app.yml
groups:
  - name: app-alerts
    rules:
      - alert: HighErrorRate
        expr: |
          sum(rate(http_requests_total{status=~"5.."}[5m]))
          / sum(rate(http_requests_total[5m])) > 0.05
        for: 5m
        labels:
          severity: critical
        annotations:
          summary: "Alta taxa de erros (> 5%)"
          description: "{{ $labels.instance }} tem {{ $value | humanizePercentage }} de erros"

      - alert: HighLatency
        expr: |
          histogram_quantile(0.95, rate(http_request_duration_seconds_bucket[5m])) > 1
        for: 5m
        labels:
          severity: warning
        annotations:
          summary: "Latencia p95 acima de 1s"

Grafana

Plataforma de visualizacao e dashboards.

Dashboard JSON

{
  "dashboard": {
    "title": "Application Metrics",
    "panels": [
      {
        "title": "Request Rate",
        "type": "graph",
        "targets": [
          {
            "expr": "sum(rate(http_requests_total[5m])) by (method)",
            "legendFormat": "{{method}}"
          }
        ]
      },
      {
        "title": "Error Rate",
        "type": "stat",
        "targets": [
          {
            "expr": "sum(rate(http_requests_total{status=~\"5..\"}[5m])) / sum(rate(http_requests_total[5m])) * 100"
          }
        ],
        "fieldConfig": {
          "defaults": {
            "unit": "percent",
            "thresholds": {
              "steps": [
                {"value": 0, "color": "green"},
                {"value": 1, "color": "yellow"},
                {"value": 5, "color": "red"}
              ]
            }
          }
        }
      }
    ]
  }
}

Provisioning

# provisioning/datasources/prometheus.yml
apiVersion: 1

datasources:
  - name: Prometheus
    type: prometheus
    access: proxy
    url: http://prometheus:9090
    isDefault: true

  - name: Loki
    type: loki
    access: proxy
    url: http://loki:3100

ELK Stack

Elasticsearch, Logstash e Kibana para gerenciamento de logs.

Logstash Pipeline

# logstash.conf
input {
  beats {
    port => 5044
  }

  kafka {
    bootstrap_servers => "kafka:9092"
    topics => ["app-logs"]
    codec => json
  }
}

filter {
  if [type] == "app" {
    grok {
      match => { "message" => "%{TIMESTAMP_ISO8601:timestamp} %{LOGLEVEL:level} %{GREEDYDATA:message}" }
    }

    date {
      match => [ "timestamp", "ISO8601" ]
    }

    if [level] == "ERROR" {
      mutate {
        add_tag => ["error"]
      }
    }
  }

  geoip {
    source => "client_ip"
  }
}

output {
  elasticsearch {
    hosts => ["elasticsearch:9200"]
    index => "logs-%{+YYYY.MM.dd}"
  }
}

Filebeat

# filebeat.yml
filebeat.inputs:
  - type: container
    paths:
      - '/var/lib/docker/containers/*/*.log'
    processors:
      - add_kubernetes_metadata:
          host: ${NODE_NAME}
          matchers:
            - logs_path:
                logs_path: "/var/lib/docker/containers/"

output.elasticsearch:
  hosts: ["elasticsearch:9200"]
  indices:
    - index: "logs-app-%{+yyyy.MM.dd}"
      when.contains:
        kubernetes.namespace: "production"

Loki (Alternativa ao ELK)

Sistema de logs da Grafana Labs, mais leve que ELK.

Configuracao

# loki-config.yml
auth_enabled: false

server:
  http_listen_port: 3100

ingester:
  lifecycler:
    ring:
      kvstore:
        store: inmemory
      replication_factor: 1

schema_config:
  configs:
    - from: 2020-01-01
      store: boltdb-shipper
      object_store: filesystem
      schema: v11
      index:
        prefix: index_
        period: 24h

storage_config:
  boltdb_shipper:
    active_index_directory: /loki/boltdb-shipper-active
    cache_location: /loki/boltdb-shipper-cache
  filesystem:
    directory: /loki/chunks

Promtail (Agente de Coleta)

# promtail-config.yml
server:
  http_listen_port: 9080

positions:
  filename: /tmp/positions.yaml

clients:
  - url: http://loki:3100/loki/api/v1/push

scrape_configs:
  - job_name: kubernetes-pods
    kubernetes_sd_configs:
      - role: pod
    pipeline_stages:
      - docker: {}
      - json:
          expressions:
            level: level
            msg: msg
      - labels:
          level:

LogQL (Queries)

# Logs de erro
{namespace="production"} |= "error"

# JSON parsing
{app="myapp"} | json | level="error"

# Contagem de erros por minuto
sum(rate({app="myapp"} |= "error" [1m])) by (pod)

# Latencia de logs
{app="myapp"} | json | latency > 1000

Distributed Tracing

OpenTelemetry

SDK padrao para instrumentacao.

// tracing.ts
import { NodeSDK } from '@opentelemetry/sdk-node'
import { getNodeAutoInstrumentations } from '@opentelemetry/auto-instrumentations-node'
import { OTLPTraceExporter } from '@opentelemetry/exporter-trace-otlp-http'
import { Resource } from '@opentelemetry/resources'
import { SemanticResourceAttributes } from '@opentelemetry/semantic-conventions'

const sdk = new NodeSDK({
  resource: new Resource({
    [SemanticResourceAttributes.SERVICE_NAME]: 'my-service',
    [SemanticResourceAttributes.SERVICE_VERSION]: '1.0.0',
  }),
  traceExporter: new OTLPTraceExporter({
    url: 'http://jaeger:4318/v1/traces',
  }),
  instrumentations: [getNodeAutoInstrumentations()],
})

sdk.start()

Jaeger

# docker-compose.yml
services:
  jaeger:
    image: jaegertracing/all-in-one:latest
    ports:
      - "16686:16686"  # UI
      - "4318:4318"    # OTLP HTTP
      - "4317:4317"    # OTLP gRPC
    environment:
      - COLLECTOR_OTLP_ENABLED=true

Stack Completa (Kubernetes)

# kube-prometheus-stack values
prometheus:
  prometheusSpec:
    retention: 15d
    storageSpec:
      volumeClaimTemplate:
        spec:
          storageClassName: gp3
          resources:
            requests:
              storage: 50Gi

grafana:
  adminPassword: ${GRAFANA_ADMIN_PASSWORD}
  persistence:
    enabled: true
    size: 10Gi
  dashboardProviders:
    dashboardproviders.yaml:
      apiVersion: 1
      providers:
        - name: 'default'
          folder: ''
          type: file
          options:
            path: /var/lib/grafana/dashboards

alertmanager:
  config:
    receivers:
      - name: 'slack'
        slack_configs:
          - channel: '#alerts'
            api_url: ${SLACK_WEBHOOK_URL}
    route:
      receiver: 'slack'
      group_by: ['alertname', 'namespace']

APM (Application Performance Monitoring)

Dynatrace

# Kubernetes OneAgent
apiVersion: dynatrace.com/v1beta1
kind: DynaKube
metadata:
  name: dynakube
  namespace: dynatrace
spec:
  apiUrl: https://xxx.live.dynatrace.com/api
  tokens: dynakube-tokens
  oneAgent:
    cloudNativeFullStack:
      tolerations:
        - effect: NoSchedule
          operator: Exists

New Relic

// newrelic.ts
import newrelic from 'newrelic'

// Instrumentacao automatica
// Configure via NEW_RELIC_LICENSE_KEY e NEW_RELIC_APP_NAME

// Custom metrics
newrelic.recordMetric('Custom/MyMetric', 100)

// Custom events
newrelic.recordCustomEvent('UserSignup', {
  userId: '123',
  plan: 'premium',
})

SonarQube (Code Quality)

# sonar-project.properties
sonar.projectKey=myapp
sonar.projectName=My Application
sonar.sources=src
sonar.tests=tests
sonar.javascript.lcov.reportPaths=coverage/lcov.info
sonar.coverage.exclusions=**/*.test.ts,**/*.spec.ts

# GitHub Actions
- name: SonarQube Scan
  uses: sonarsource/sonarqube-scan-action@master
  env:
    SONAR_TOKEN: ${{ secrets.SONAR_TOKEN }}
    SONAR_HOST_URL: ${{ secrets.SONAR_HOST_URL }}

Recursos

DevOps e CI/CD

Introdução ao Docker

Observabilidade

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