IOException：通過 AJP 使用 Apache 2、mod_jk 和 Tomcat 讀取套接字失敗

當我的使用者使用他們的 Android 設備連接到 JSON Rest Service 時，我不時收到以下異常：

java.io.IOException: Socket read failed
      at org.apache.coyote.ajp.AjpProcessor.read(AjpProcessor.java:313)
      at org.apache.coyote.ajp.AjpProcessor.readMessage(AjpProcessor.java:364)
      at org.apache.coyote.ajp.AjpProcessor.receive(AjpProcessor.java:331)
      at org.apache.coyote.ajp.AbstractAjpProcessor.refillReadBuffer(AbstractAjpProcessor.java:614)
      at org.apache.coyote.ajp.AbstractAjpProcessor$SocketInputBuffer.doRead(AbstractAjpProcessor.java:1065)
      at org.apache.coyote.Request.doRead(Request.java:422)
      at org.apache.catalina.connector.InputBuffer.realReadBytes(InputBuffer.java:290)
      at org.apache.tomcat.util.buf.ByteChunk.substract(ByteChunk.java:431)
      at org.apache.catalina.connector.InputBuffer.read(InputBuffer.java:315)
      at org.apache.catalina.connector.CoyoteInputStream.read(CoyoteInputStream.java:200)
      at org.codehaus.jackson.impl.ByteSourceBootstrapper.ensureLoaded(ByteSourceBootstrapper.java:340)
      at org.codehaus.jackson.impl.ByteSourceBootstrapper.detectEncoding(ByteSourceBootstrapper.java:137)
      at org.codehaus.jackson.impl.ByteSourceBootstrapper.constructParser(ByteSourceBootstrapper.java:197)
      at org.codehaus.jackson.JsonFactory._createJsonParser(JsonFactory.java:542)
      at org.codehaus.jackson.JsonFactory.createJsonParser(JsonFactory.java:389)
      at org.codehaus.jackson.map.ObjectMapper.readValue(ObjectMapper.java:1454)
      at org.springframework.http.converter.json.MappingJacksonHttpMessageConverter.readInternal(MappingJacksonHttpMessageConverter.java:124)
      at org.springframework.http.converter.AbstractHttpMessageConverter.read(AbstractHttpMessageConverter.java:153)
      at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.readWithMessageConverters(HandlerMethodInvoker.java:641)
      at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.resolveRequestBody(HandlerMethodInvoker.java:605)
      at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.resolveHandlerArguments(HandlerMethodInvoker.java:354)
      at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:171)
      at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:436)
      at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:424)
      at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:923)
      at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:852)
      at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:882)
      at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:789)

我在跑步

• 阿帕奇/2.2.20
• mod_jk 1.2.36
• 雄貓 7.0.27

這可能與超時有關嗎？就像客戶端關閉連接並且伺服器無法再從套接字讀取一樣？還是更可能是伺服器配置的問題？

更新：

執行一些 Apache 日誌 awk 我發現以下 Apache 日誌行對應於那些 Tomcat 日誌異常：

192.186.30.116 - - [25/Jun/2012:10:47:14 +0200] "POST /myapp/methodX HTTP/1.1" 400 145 "-" "clientApp BlackBerry9360/7.0.0.530 VendorID/168" 10012655 
192.186.30.120 - - [25/Jun/2012:10:53:13 +0200] "POST /myapp/methodY HTTP/1.1" 400 145 "-" "clientApp BlackBerry9800/6.0.0.668 VendorID/124" 10012164 
192.186.30.116 - - [25/Jun/2012:10:53:36 +0200] "POST /myapp/methodZ HTTP/1.1" 400 145 "-" "clientApp BlackBerry9360/7.0.0.530 VendorID/168" 10012677 
192.82.68.16 - - [25/Jun/2012:11:22:31 +0200] "POST /myapp/methodX HTTP/1.1" 400 145 "-" "clientApp BlackBerry9930/7.1.0.402 VendorID/104" 10012667 
192.82.68.16 - - [25/Jun/2012:11:23:21 +0200] "POST /myapp/methodZ HTTP/1.1" 400 145 "-" "clientApp BlackBerry9930/7.1.0.402 VendorID/104" 10012562 

您可以看到針對這些請求發送給客戶端的狀態程式碼 400 Bad Request。

行尾的大數字（例如 10012562）顯示請求在伺服器上處理的時間（以微秒為單位）：10012562 = 大約 10 秒

看起來十秒鐘後連接以某種方式終止？我查看了 AJP 配置，但沒有定義超時 - 10 秒將是我未使用的非同步請求的超時

我找到了原因。問題是由 Apache 模組 mod_reqtimeout 的預設配置引起的：

<IfModule reqtimeout_module>

# mod_reqtimeout limits the time waiting on the client to prevent an
# attacker from causing a denial of service by opening many connections
# but not sending requests. This file tries to give a sensible default
# configuration, but it may be necessary to tune the timeout values to
# the actual situation. Note that it is also possible to configure
# mod_reqtimeout per virtual host.


# Wait max 20 seconds for the first byte of the request line+headers
# From then, require a minimum data rate of 500 bytes/s, but don't
# wait longer than 40 seconds in total.
# Note: Lower timeouts may make sense on non-ssl virtual hosts but can
# cause problem with ssl enabled virtual hosts: This timeout includes
# the time a browser may need to fetch the CRL for the certificate. If
# the CRL server is not reachable, it may take more than 10 seconds
# until the browser gives up.
RequestReadTimeout header=20-40,minrate=500

# Wait max 10 seconds for the first byte of the request body (if any)
# From then, require a minimum data rate of 500 bytes/s
RequestReadTimeout body=10,minrate=500

</IfModule>

我猜黑莓客戶端受到的打擊更大，因為通過 RIM BIS 基礎設施發送請求正文需要更長的時間。

將該值設置為 100 秒並監視客戶端是否仍然受到影響。

引用自：https://serverfault.com/questions/389834