一、核心架构
1. 进程模型
graph TB
subgraph Master进程
M[Master Process]
end
subgraph Worker进程
W1[Worker 1]
W2[Worker 2]
W3[Worker 3]
end
subgraph Cache进程
C1[Cache Loader]
C2[Cache Manager]
end
M --> W1
M --> W2
M --> W3
M --> C1
M --> C2
classDef master fill:#f96,stroke:#333
classDef worker fill:#9cf,stroke:#333
classDef cache fill:#fcf,stroke:#333
class M master
class W1,W2,W3 worker
class C1,C2 cache
2. 核心组件
以下是 Nginx 的大致完整核心类结构，仅供参考，与实际类图不是完全一致。
主要包含：
- 请求处理相关的核心类 (ngx_http_request_t)
- 连接管理相关类 (ngx_connection_t, ngx_event_t)
- HTTP/2 相关类 (ngx_http2_stream_t, ngx_http2_frame_t)
- 上游代理相关类 (ngx_http_upstream_t, ngx_peer_connection_t)
classDiagram
class ngx_http_request_t {
fill:#e6f3ff
+ngx_connection_t *connection
+ngx_http_upstream_t *upstream
+ngx_buf_t *response_body
+ngx_http_core_module *core_module
+ngx_array_t *headers_in
+ngx_array_t *headers_out
+ngx_str_t method
+ngx_str_t uri
+ngx_str_t request_body
+ngx_int_t status
+ngx_str_t response_header
+ngx_http2_stream_t *http2_stream
+process_request()
+send_response()
}
note for ngx_http_request_t "处理 HTTP 请求的核心类
- 管理请求的整个生命周期
- 包含请求头、URI、请求体等信息
- 支持 HTTP/1 和 HTTP/2"
class ngx_connection_t {
+int fd
+ngx_sockaddr_t *sockaddr
+ngx_event_t *read_event
+ngx_event_t *write_event
+read_data()
+write_data()
+void *data
}
note for ngx_connection_t "表示客户端连接
- 管理套接字和事件
- 处理数据读写"
class ngx_http_upstream_t {
+ngx_peer_connection_t *peer
+ngx_http_request_t *request
+ngx_str_t upstream_uri
+ngx_int_t connect_timeout
+ngx_int_t read_timeout
+send_request()
+receive_response()
}
note for ngx_http_upstream_t "处理与上游服务器的交互
- 管理代理连接
- 处理超时和重试"
class ngx_event_t {
+int event_type
+ngx_connection_t *connection
+handle_event()
}
class ngx_buf_t {
+char *data
+size_t length
+size_t capacity
+append_data()
}
note for ngx_buf_t "缓冲区管理
- 处理请求和响应数据
- 支持内存和文件映射"
class ngx_peer_connection_t {
+ngx_str_t host
+int port
+int connection_fd
+connect_to_peer()
}
note for ngx_peer_connection_t "上游连接管理
- 维护与上游服务器的连接
- 处理连接建立和断开"
class ngx_http2_stream_t {
+int stream_id
+ngx_http_request_t *request
+ngx_http2_frame_t *frame
+handle_frame()
+send_data()
}
note for ngx_http2_stream_t "HTTP/2 流管理
- 处理 HTTP/2 多路复用
- 管理流的生命周期"
class ngx_http2_frame_t {
+int type
+int length
+char *data
+parse_frame()
}
note for ngx_http2_frame_t "HTTP/2 帧处理
- 解析和生成 HTTP/2 帧
- 支持各种帧类型"
ngx_http_request_t --> ngx_connection_t
ngx_http_request_t --> ngx_http_upstream_t
ngx_http_request_t --> ngx_buf_t
ngx_http_request_t --> ngx_http2_stream_t
ngx_http2_stream_t --> ngx_http2_frame_t
ngx_connection_t --> ngx_event_t
ngx_connection_t --> ngx_peer_connection_t
ngx_http_upstream_t --> ngx_peer_connection_t
二、请求处理流程
1. HTTP/1.1 请求流程
sequenceDiagram
participant Client
participant Worker
participant Request
participant Upstream
Client->>Worker: 发送 HTTP/1.1 请求
Worker->>Request: 创建 ngx_http_request_t
Request->>Upstream: 创建 upstream 连接
Upstream->>Request: 返回响应
Request->>Worker: 处理响应
Worker->>Client: 发送响应
2. HTTP/2 请求流程
sequenceDiagram
participant Client
participant Worker
participant Stream
participant Request
participant Upstream
Client->>Worker: 发送 HTTP/2 请求
Worker->>Stream: 创建 HTTP/2 流
Stream->>Request: 创建 ngx_http_request_t
Request->>Upstream: 创建 upstream 连接
Upstream->>Request: 返回响应
Request->>Stream: 处理响应
Stream->>Client: 通过流发送响应
三、模块化架构
graph TB
subgraph Core[核心模块]
Event[事件模块]
HTTP[HTTP模块]
Stream[Stream模块]
end
subgraph Handlers[处理器]
Static[静态文件]
Proxy[代理]
FastCGI[FastCGI]
end
subgraph Filters[过滤器]
Headers[头部过滤]
Gzip[压缩]
SSL[SSL]
end
Core --> Handlers
Core --> Filters
四、性能优化机制
1. 事件处理
graph LR
subgraph EventLoop[事件循环]
Epoll[epoll/kqueue]
Events[事件队列]
Handler[事件处理器]
end
subgraph Connection[连接管理]
Pool[连接池]
Cache[缓存]
end
Epoll --> Events
Events --> Handler
Handler --> Pool
2. 缓存系统
graph TB
subgraph Cache[缓存系统]
Manager[缓存管理器]
Memory[内存缓存]
Disk[磁盘缓存]
end
subgraph Policy[缓存策略]
LRU[LRU]
TTL[TTL]
end
Manager --> Memory
Manager --> Disk
Policy --> Manager
