GCP提供两种负载均衡器，即网络和 HTTP ，其中前者适用于第4层，后者适用于第7层。
还有一份文档说明即使HTTP流量也可以由网络负载均衡器进行负载平衡。这略微混淆了为GCP中的Web应用程序选择哪个负载均衡器。在为项目选择差异之前，最好先了解这些差异。
基于工作流程，设置，区域/区域，会话亲和力<的选项，它们之间有何区别？ / strong>，和其他设置？
答案 0 :(得分：17)
网络负载均衡器与HTTP（s）负载均衡器
+---------------------+------------------------------------------+------------------------------------------------------+
| Category | Network Load Balancing (NLB) | HTTP(S) Load Balancing (HLB) |
+---------------------+------------------------------------------+------------------------------------------------------+
| 1. Region / | NLB supports only within a region. | HLB supports both within cross-region |
| Cross-Region | Does not support cross-region | load balancing. |
| | load balancing | |
+---------------------+------------------------------------------+------------------------------------------------------+
| 2. Load balancing | NLB is based on IP address, port | HLB is based only on HTTP and HTTPS |
| based on | and protocol type. Any TCP/UDP | protocols. |
| | traffic, even SMTP can be | |
| | load balanced. | |
+---------------------+------------------------------------------+------------------------------------------------------+
| 3. Packet | Packet inspection is possible and | HLB cannot inspect packets. |
| inspection | load balance based on packets | |
+---------------------+------------------------------------------+------------------------------------------------------+
| 4. Instance | No need of creating instance group. | Managed / UnManaged Instance group |
| Group | Target pools need to be created. | is necessary for creating HTTP / HTTPS |
| | Instance can be just tagged to the pool. | load balancer. |
| | Ideal for unmanaged instance group | |
| | where instances are non homogeneous. | |
+---------------------+------------------------------------------+------------------------------------------------------+
| 5. Workflow | Forwarding rules is the starting point. | This is quite complex in HTTP(s) load balancer. |
| | It directs the request to the | Global forwarding rulesroutes direct the request |
| | target pools from which compute | to target HTTP proxy, which in turn checks the |
| | engines will pick the request. | URL map to determine appropriate backend |
| | | services. These services in turn direct the request |
| | Forwarding rules -> target pool | to the instance group. |
| | -> instances | |
| | | |
| | | Global forwarding rules -> Target HTTP proxy -> |
| | | URL map -> Backend Sevices -> instance group |
+---------------------+------------------------------------------+------------------------------------------------------+
| 6. Types of | Basic network load balancer which | 1. Cross-region load balancer uses only one |
| load balancer | directs the request based on IP address, | global IP address and routes the request |
| | port and the protocol within the region. | to the nearest region. |
| | | |
| | | 2. Content-based load balancer is based |
| | | on the URL path. Different path rules need |
| | | different backend services. for eg: /video |
| | | and /static require two separate backend services. |
+---------------------+------------------------------------------+------------------------------------------------------+
| 7. Session affinity | Session affinity can be set, but only | 1. Client IP Affinity: This directs the same |
| | during the creation of target pool. | client ip to same backend instance by |
| | Once it is set, the value | computing hash of the IP. |
| | cannot be changed. | 2. Generated Cookie Affinity: Load balancer stores |
| | | cookie in clients and directs the same client to |
| | | same instance with the help of retrieved cookie. |
+---------------------+------------------------------------------+------------------------------------------------------+
| 8. Health check | Health check is optional, but network | Health can be verified by either using HTTP |
| | load balancing relies on HTTP Health | heath check or HTTPS health check. |
| | checks for determining instance health. | |
+---------------------+------------------------------------------+------------------------------------------------------+
上表基于我的观点。如果有任何不正确或如果我错过了什么，请随时发表评论，我会将其添加到表格中。
以下link有关在 GCP中设置 HTTP负载均衡器的说明。
答案 1 :(得分：0)
答案 2 :(得分：0)
下面通常是网络负载均衡器和Http负载均衡器之间的区别。
网络负载平衡器（第4层）： 这是基于网络变量（例如IP地址和目标端口）的流量分配。它是第4层（TCP）及以下的层，并且不旨在考虑应用程序层的任何内容，例如内容类型，cookie数据，自定义标头，用户位置或应用程序行为。它是无上下文的，仅关心以这种方式定向的数据包中包含的网络层信息。
应用程序负载平衡器（第7层） 这是从网络层到应用程序层的基于多个变量的请求分布。它是上下文感知的，可以像基于变量的组合一样轻松地基于任何单个变量定向请求。应用程序是基于应用程序的特殊行为进行负载平衡的，而不仅仅是基于服务器（操作系统或虚拟化层）信息。它能够基于规则，基于主机或基于路径来路由HTTP和HTTPS流量。就像NLB一样，每个目标可以位于不同的端口上。
两者之间的另一个区别很重要，因为网络负载平衡无法确保应用程序的可用性。这是因为它的决策仅基于网络和TCP层变量，而根本不了解应用程序。通常，网络负载平衡器将根据服务器响应ICMP ping或正确完成三向TCP握手的能力来确定“可用性”。应用程序负载平衡器更加深入，不仅可以基于特定页面的成功HTTP GET来确定可用性，还可以基于输入参数来验证内容是否符合预期。