云计算中的负载均衡是什么？

Load balancing is the practice of spreading incoming traffic across several servers, also referred to as traffic dispatching because it works as a traffic director for websites and applications. It distributes user traffic across multiple servers to manage the load on individual servers, which can affect system operation. In cloud computing, it is usually a managed software service rather than a dedicated hardware appliance.

负载均衡在以下方面至关重要 云环境 和SaaS应用程序中，因为那里的资源是虚拟的，有时可能会因流量过载。它可以确保：

• 高可用性： 如果一台服务器宕机，流量会自动重定向到其他功能正常的服务器。
• 性能： 在同时接收多个请求时，保持应用程序的响应。
• 可扩展性： 向池中添加更多服务器以处理不断增长的流量。

请记住： 所有服务器协同工作，同时处理总工作负载，以提高所提供产品或服务的可用性。

真实案例： 像Netflix这样的流媒体平台采用负载均衡，以便同时向数百万用户提供无缝的视频流。

Think of it like shopping in a busy supermarket where instead of everybody queueing up at one counter, several counters are opened to divide the load. Load balancers function similarly; they distribute incoming requests across the servers, often to the least loaded one.

Some of the common load balancing techniques include round-robin, least connections, and IP hash, each with its advantages and use cases. Load balancers also differ by layer: a Layer 4 (transport) balancer routes by IP address and port, while a Layer 7 (application) balancer reads the request itself, such as its URL (F5).

Load balancing decides which server receives each request, while 可扩展性 changes how many servers there are:

• 可扩展性： 能够增加或减少资源（如服务器）并管理不同的流量级别。
• 负载均衡： 这是将流量分配到可用资源上的行为。
• 云弹性： 包括基于流量自动扩展资源，以及可扩展性和负载分配的集成。

负载均衡广泛应用于 SaaS 应用程序中，以提高用户满意度和服务的可用性。例如：

• Microsoft Office 365： 平衡数百万用户访问电子邮件、文档和其他服务的流量。
• Zoom视频会议： 将视频或音频流量分配到多个服务器，以保持通信质量。
• Salesforce CRM： Balances the volume of customer relationship management data and transactions for responsiveness 和 availability for 销售团队.