Tengine2.2.2官方健康檢查示例

check interval=3000 rise=2 fall=5 timeout=1000 type=http;
check_keepalive_requests 100;
check_http_send "HEAD / HTTP/1.1\r\nConnection: keep-alive\r\n\r\n";
check_http_expect_alive http_2xx http_3xx;

結果一直報錯，通過抓包工具發現伺服器端返回400 Bad Request

查詢http1.1協議發現請求當中必須包含host請求頭，（其值可以為空），否則伺服器會返回400 Bad Request錯誤

A client MUST include a Host header field in all HTTP/1.1 request messages . If the requested URI does not include an Internet host name for the service being requested, then the Host header field MUST be given with an empty value. An HTTP/1.1 proxy MUST ensure that any request message it forwards does contain an appropriate Host header field that identifies the service being requested by the proxy. All Internet-based HTTP/1.1 servers MUST respond with a 400 (Bad Request) status code to any HTTP/1.1 request message which lacks a Host header field.

我修改後的示例

check interval=3000 rise=2 fall=5 timeout=2000 type=http;
check_keepalive_requests 100;
check_http_send "GET / HTTP/1.1\r\nHost:\r\nConnection: keep-alive\r\n\r\n";
check_http_expect_alive http_2xx http_3xx;

其中加上了host請求頭，值可以為空。

測試無誤，nginx與tomcat使用http1.1長連線進行健康檢查.

有個配置check_shm_size size

所有的後端伺服器健康檢查狀態都存於共享記憶體中，該指令可以設定共享記憶體的大小。預設是1M，如果你有1千臺以上的伺服器並在配置的時候出現了錯誤，就可能需要擴大該記憶體的大小。