package redis_test import ( "fmt" "sync/atomic" "time" redis "gopkg.in/redis.v5" ) func Example_instrumentation() { ring := redis.NewRing(&redis.RingOptions{ Addrs: map[string]string{ "shard1": ":6379", }, }) ring.ForEachShard(func(client *redis.Client) error { wrapRedisProcess(client) return nil }) for { ring.Ping() } } func wrapRedisProcess(client *redis.Client) { const precision = time.Microsecond var count, avgDur uint32 go func() { for _ = range time.Tick(3 * time.Second) { n := atomic.LoadUint32(&count) dur := time.Duration(atomic.LoadUint32(&avgDur)) * precision fmt.Printf("%s: processed=%d avg_dur=%s\n", client, n, dur) } }() client.WrapProcess(func(oldProcess func(redis.Cmder) error) func(redis.Cmder) error { return func(cmd redis.Cmder) error { start := time.Now() err := oldProcess(cmd) dur := time.Since(start) const decay = float64(1) / 100 ms := float64(dur / precision) for { avg := atomic.LoadUint32(&avgDur) newAvg := uint32((1-decay)*float64(avg) + decay*ms) if atomic.CompareAndSwapUint32(&avgDur, avg, newAvg) { break } } atomic.AddUint32(&count, 1) return err } }) }