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|
package redis
import (
"context"
"errors"
"fmt"
"net"
"time"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promauto"
redis "github.com/redis/go-redis/v9"
"gitlab.com/gitlab-org/gitlab/workhorse/internal/config"
_ "gitlab.com/gitlab-org/gitlab/workhorse/internal/helper"
)
var (
rdb *redis.Client
// found in https://github.com/redis/go-redis/blob/c7399b6a17d7d3e2a57654528af91349f2468529/sentinel.go#L626
errSentinelMasterAddr error = errors.New("redis: all sentinels specified in configuration are unreachable")
TotalConnections = promauto.NewCounter(
prometheus.CounterOpts{
Name: "gitlab_workhorse_redis_total_connections",
Help: "How many connections gitlab-workhorse has opened in total. Can be used to track Redis connection rate for this process",
},
)
ErrorCounter = promauto.NewCounterVec(
prometheus.CounterOpts{
Name: "gitlab_workhorse_redis_errors",
Help: "Counts different types of Redis errors encountered by workhorse, by type and destination (redis, sentinel)",
},
[]string{"type", "dst"},
)
)
const (
// Max Idle Connections in the pool.
defaultMaxIdle = 1
// Max Active Connections in the pool.
defaultMaxActive = 1
// Timeout for Read operations on the pool. 1 second is technically overkill,
// it's just for sanity.
defaultReadTimeout = 1 * time.Second
// Timeout for Write operations on the pool. 1 second is technically overkill,
// it's just for sanity.
defaultWriteTimeout = 1 * time.Second
// Timeout before killing Idle connections in the pool. 3 minutes seemed good.
// If you _actually_ hit this timeout often, you should consider turning of
// redis-support since it's not necessary at that point...
defaultIdleTimeout = 3 * time.Minute
)
// createDialer references https://github.com/redis/go-redis/blob/b1103e3d436b6fe98813ecbbe1f99dc8d59b06c9/options.go#L214
// it intercepts the error and tracks it via a Prometheus counter
func createDialer(sentinels []string) func(ctx context.Context, network, addr string) (net.Conn, error) {
return func(ctx context.Context, network, addr string) (net.Conn, error) {
var isSentinel bool
for _, sentinelAddr := range sentinels {
if sentinelAddr == addr {
isSentinel = true
break
}
}
dialTimeout := 5 * time.Second // go-redis default
destination := "redis"
if isSentinel {
// This timeout is recommended for Sentinel-support according to the guidelines.
// https://redis.io/topics/sentinel-clients#redis-service-discovery-via-sentinel
// For every address it should try to connect to the Sentinel,
// using a short timeout (in the order of a few hundreds of milliseconds).
destination = "sentinel"
dialTimeout = 500 * time.Millisecond
}
netDialer := &net.Dialer{
Timeout: dialTimeout,
KeepAlive: 5 * time.Minute,
}
conn, err := netDialer.DialContext(ctx, network, addr)
if err != nil {
ErrorCounter.WithLabelValues("dial", destination).Inc()
} else {
if !isSentinel {
TotalConnections.Inc()
}
}
return conn, err
}
}
// implements the redis.Hook interface for instrumentation
type sentinelInstrumentationHook struct{}
func (s sentinelInstrumentationHook) DialHook(next redis.DialHook) redis.DialHook {
return func(ctx context.Context, network, addr string) (net.Conn, error) {
conn, err := next(ctx, network, addr)
if err != nil && err.Error() == errSentinelMasterAddr.Error() {
// check for non-dialer error
ErrorCounter.WithLabelValues("master", "sentinel").Inc()
}
return conn, err
}
}
func (s sentinelInstrumentationHook) ProcessHook(next redis.ProcessHook) redis.ProcessHook {
return func(ctx context.Context, cmd redis.Cmder) error {
return next(ctx, cmd)
}
}
func (s sentinelInstrumentationHook) ProcessPipelineHook(next redis.ProcessPipelineHook) redis.ProcessPipelineHook {
return func(ctx context.Context, cmds []redis.Cmder) error {
return next(ctx, cmds)
}
}
func GetRedisClient() *redis.Client {
return rdb
}
// Configure redis-connection
func Configure(cfg *config.RedisConfig) error {
if cfg == nil {
return nil
}
var err error
if len(cfg.Sentinel) > 0 {
rdb = configureSentinel(cfg)
} else {
rdb, err = configureRedis(cfg)
}
return err
}
func configureRedis(cfg *config.RedisConfig) (*redis.Client, error) {
if cfg.URL.Scheme == "tcp" {
cfg.URL.Scheme = "redis"
}
opt, err := redis.ParseURL(cfg.URL.String())
if err != nil {
return nil, err
}
opt.DB = getOrDefault(cfg.DB, 0)
opt.Password = cfg.Password
opt.PoolSize = getOrDefault(cfg.MaxActive, defaultMaxActive)
opt.MaxIdleConns = getOrDefault(cfg.MaxIdle, defaultMaxIdle)
opt.ConnMaxIdleTime = defaultIdleTimeout
opt.ReadTimeout = defaultReadTimeout
opt.WriteTimeout = defaultWriteTimeout
opt.Dialer = createDialer([]string{})
return redis.NewClient(opt), nil
}
func configureSentinel(cfg *config.RedisConfig) *redis.Client {
sentinelPassword, sentinels := sentinelOptions(cfg)
client := redis.NewFailoverClient(&redis.FailoverOptions{
MasterName: cfg.SentinelMaster,
SentinelAddrs: sentinels,
Password: cfg.Password,
SentinelPassword: sentinelPassword,
DB: getOrDefault(cfg.DB, 0),
PoolSize: getOrDefault(cfg.MaxActive, defaultMaxActive),
MaxIdleConns: getOrDefault(cfg.MaxIdle, defaultMaxIdle),
ConnMaxIdleTime: defaultIdleTimeout,
ReadTimeout: defaultReadTimeout,
WriteTimeout: defaultWriteTimeout,
Dialer: createDialer(sentinels),
})
client.AddHook(sentinelInstrumentationHook{})
return client
}
// sentinelOptions extracts the sentinel password and addresses in <host>:<port> format
// the order of priority for the passwords is: SentinelPassword -> first password-in-url
func sentinelOptions(cfg *config.RedisConfig) (string, []string) {
sentinels := make([]string, len(cfg.Sentinel))
sentinelPassword := cfg.SentinelPassword
for i := range cfg.Sentinel {
sentinelDetails := cfg.Sentinel[i]
sentinels[i] = fmt.Sprintf("%s:%s", sentinelDetails.Hostname(), sentinelDetails.Port())
if pw, exist := sentinelDetails.User.Password(); exist && len(sentinelPassword) == 0 {
// sets password using the first non-empty password
sentinelPassword = pw
}
}
return sentinelPassword, sentinels
}
func getOrDefault(ptr *int, val int) int {
if ptr != nil {
return *ptr
}
return val
}
|
