仅用8台虚拟机处理每日数十亿笔交易？PayPal咋做到的？

“PayPal如何仅用8台虚拟机扩展至每日处理数十亿交易？”看到这篇文章的时候，被这一惊人壮举给震撼，现在一起看看具体的实践历程。

package mainimport (   "fmt"   "sync")// Actor represents an actor with its own state and a channel for receiving messages.type Actor struct {   state int   mailbox chan int}// NewActor creates a new actor with an initial state.func NewActor(initialState int) *Actor {   return &Actor{       state: initialState,       mailbox: make(chan int),   }}// ProcessMessage processes a message by updating the actor's state.func (a *Actor) ProcessMessage(message int) {   fmt.Printf("Actor %d processing message: %d\n", a.state, message)   a.state += message}// Run simulates the actor's runtime by continuously processing messages from the mailbox.func (a *Actor) Run(wg *sync.WaitGroup) {   defer wg.Done()   for {       message := <-a.mailbox       a.ProcessMessage(message)   }}// System represents the actor system managing multiple actors.type System struct {   actors []*Actor}// NewSystem creates a new actor system with a given number of actors.func NewSystem(numActors int) *System {   system := &System{}   for i := 1; i <= numActors; i++ {       actor := NewActor(i)       system.actors = append(system.actors, actor)       go actor.Run(nil)   }   return system}// SendMessage sends a message to a randomly selected actor in the system.func (s *System) SendMessage(message int) {   actorIndex := message % len(s.actors)   s.actors[actorIndex].mailbox <- message}func main() {  // Create an actor system with 3 actors.   actorSystem := NewSystem(3)  // Send messages to the actors concurrently.   var wg sync.WaitGroup   for i := 1; i <= 5; i++ {       wg.Add(1)       go func(message int) {           defer wg.Done()           actorSystem.SendMessage(message)       }(i)   }  // Wait for all messages to be processed.   wg.Wait()}

Actor 3 processing message: 5Actor 8 processing message: 2Actor 1 processing message: 3Actor 2 processing message: 1Actor 3 processing message: 4