redis pool.Get() takes a longer time to return connection in golang

Question

This is the code I have written to get to create redisPool at compile time.

var RedisPool *redis.Pool   //set at compile time 
func RedisSetup() {
        RedisPool = newRedisPool(serverUrl, password)
        c := RedisPool.Get()
    defer c.Close()
    pong, err := redis.String(c.Do("PING"))
    if err != nil{
        fmt.Println("error while connecting redis ", err)
    }
    fmt.Println("Redis Ping:", pong)
}
func newRedisPool(server, password string) *redis.Pool {
    pool :=  &redis.Pool{
        MaxIdle:     10,
        MaxActive: 100,
        IdleTimeout: 5 * time.Second,
        Dial: func() (redis.Conn, error) {
            c, err := redis.Dial("tcp", server, redis.DialUseTLS(true), redis.DialTLSSkipVerify(true))
            if err != nil {
                log.Printf("ERROR: fail initializing the redis pool: %s", err.Error())
                fmt.Println("server conn err", err)
                return nil, err
            }
            if password != "" {
                if _, err := c.Do("AUTH", password); err != nil {
                    c.Close()
                    fmt.Println("auth err", err)
                    return nil, err
                }
            }
            return c, err
        },
        TestOnBorrow: func(c redis.Conn, t time.Time) error {
            _, err := c.Do("PING")
            return err
        },
    }
    return  pool
}

Now, this is the function i am using for doing redis operations like set or get.

func GetCacheValue(ctx context.Context, key string) (string, error) {
    startTime := time.Now()
    span, ctx := apm.StartSpan(ctx, "get cache " + key, "request")
    defer span.End()
    conn := apmredigo.Wrap(getPool(ctx)).WithContext(ctx)
    val, err := redis.String(conn.Do("GET", key))
    if err != nil {
        return "", err
    }
    redisPool.Close()
    fmt.Println("\n redis get time : ", time.Since(startTime), "\n")
    return val, nil
} 


func getPool(ctx context.Context) redis.Conn {
    startTime :=time.Now()
    span, ctx := apm.StartSpan(ctx, "get connection ", "request")
    defer span.End()
    conn :=  RedisPool.Get()
    fmt.Println("\nPool get time : ", time.Since(startTime), "\n")
    return conn
}

This is the output i am getting, I have hit 3 request and got different different response time ,sometime it respond within 1ms or 2ms and sometime it takes around 100ms. Why so much difference? Can someone please help, is there anything I am missing?

console output 1 console output 2 apm server output