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Redis Exporter - Project Summary

Overview

Prometheus exporter for Redis, Sentinel, Cluster, Dragonfly, Valkey, and Tile38. Written in Go using gomodule/redigo for Redis and prometheus/client_golang for metrics.

Architecture

Entry point: main.go → creates Exporter struct → registers with Prometheus → starts HTTP server.

Scrape flow: HTTP request → Collect() → scrapeRedisHost() → connect → CONFIG GET → INFO ALL → feature-specific commands → register metrics.

Key struct: Exporter implements prometheus.Collector (Describe/Collect) and http.Handler.

Exporter Directory Structure

File Purpose
exporter.go Core: Exporter struct, Options, Collect(), scrapeRedisHost(), metric registration
redis.go Connection helpers: connectToRedis(), connectToRedisCluster(), configureOptions()
info.go INFO ALL parsing: extractInfoMetrics(), extractConfigMetrics(), commandstats, latencystats
keys.go Key inspection: check-keys, check-single-keys, count-keys, pipelined batch operations
streams.go XINFO STREAM/GROUPS/CONSUMERS metrics
key_groups.go SCAN-based key grouping with memory analysis
clients.go CLIENT LIST parsing with IPv4/IPv6 support
sentinels.go Sentinel master/slave/sentinel metrics, ckquorum
metrics.go Metric description helpers, counter/gauge map definitions
http.go HTTP handlers: /metrics, /scrape, /health, /-/reload, /discover-cluster-nodes
tls.go TLS config: client certs, CA loading, skip verification
pwd_file.go JSON password file loading (URI→password map)
nodes.go Cluster node discovery from CLUSTER INFO
modules.go Redis module metrics from INFO MODULES
search_indexes.go RediSearch FT._LIST / FT.INFO metrics
slowlog.go SLOWLOG GET metrics
latency.go LATENCY LATEST and LATENCY HISTOGRAM
lua.go Custom Lua script execution via EVAL
tile38.go Tile38-specific metrics

Key Configuration (Options struct)

  • Auth: User/Password, PasswordMap, RedisPwdFile, HTTP BasicAuth (bcrypt support)
  • TLS: ClientCert/Key, CACert, SkipTLSVerification
  • Metric toggles: InclConfigMetrics, InclModulesMetrics, InclSearchIndexesMetrics, InclSystemMetrics, ExportClientList
  • Key inspection: CheckKeys, CheckSingleKeys, CheckStreams, CountKeys, CheckKeyGroups (with MaxDistinctKeyGroups)
  • Performance: CheckKeysBatchSize (pipelining), ConnectionTimeouts, SkipCheckKeysForRoleMaster
  • DB type: IsCluster, IsTile38; Valkey/Dragonfly auto-detected via URL scheme

HTTP Endpoints

  • /metrics - Standard Prometheus scrape
  • /scrape?target=<uri> - Dynamic single-target scraping (supports query param overrides)
  • /health - Health check
  • /-/reload - Reload password file
  • /discover-cluster-nodes - JSON cluster node list for Prometheus relabeling

Notable Design Decisions

  • Pipelining: Batched key operations for non-cluster; sequential for cluster mode
  • Role-aware: Detects master/slave from INFO; can skip key checks on master
  • Keyspace parsing: Supports 4-6 fields for Redis/Dragonfly/Valkey compatibility
  • URL normalization: valkey:// → redis://, valkeys:// → rediss://
  • Error resilience: Individual metric errors don't abort the scrape
  • Metric registration: Two-phase (descriptions at init, values at scrape) with dynamic metrics for command stats, key names, etc.

Testing

19 test files. Integration tests use TEST_REDIS_URI env var for live Redis instances. Covers parsing, HTTP handlers, cluster, sentinel, streams, key groups, search indexes, and client list (IPv6, RESP versions).

Build & Run

go build .
./redis_exporter --redis.addr=redis://localhost:6379

Key flags: --redis.addr, --redis.password, --check-keys, --check-streams, --is-cluster, --tls-client-cert-file, --lua-script, --namespace