问题描述
我正在使用 spring-boot 应用程序和 fastxml 来反序列化我的请求。在使用 jmeter 对我的 java 应用程序进行压力测试时，许多 nio 线程正在进入 TIMED_WAITING 状态。他们正在等待的语句是，
mapper.readValue(request.getInputStream(),MyRequest.class);
以下是线程转储的摘录，
"http-nio-8080-exec-1415" #88733 daemon prio=5 os_prio=0 tid=0x00007f98c03d1800 nid=0x2240f in Object.wait() [0x00007f9744dcb000]
java.lang.Thread.State: TIMED_WAITING (on object monitor)
at java.lang.Object.wait(Native Method)
at org.apache.tomcat.util.net.NioEndpoint$NioSocketWrapper.fillReadBuffer(NioEndpoint.java:1244)
- locked <0x00000007762846e0> (a java.util.concurrent.Semaphore)
at org.apache.tomcat.util.net.NioEndpoint$NioSocketWrapper.read(NioEndpoint.java:1158)
at org.apache.coyote.http11.Http11InputBuffer.fill(Http11InputBuffer.java:736)
at org.apache.coyote.http11.Http11InputBuffer.access$300(Http11InputBuffer.java:42)
at org.apache.coyote.http11.Http11InputBuffer$SocketInputBuffer.doRead(Http11InputBuffer.java:1099)
at org.apache.coyote.http11.filters.IdentityInputFilter.doRead(IdentityInputFilter.java:102)
at org.apache.coyote.http11.Http11InputBuffer.doRead(Http11InputBuffer.java:247)
at org.apache.coyote.Request.doRead(Request.java:551)
at org.apache.catalina.connector.InputBuffer.realReadBytes(InputBuffer.java:336)
at org.apache.catalina.connector.InputBuffer.checkByteBufferEof(InputBuffer.java:632)
at org.apache.catalina.connector.InputBuffer.read(InputBuffer.java:362)
at org.apache.catalina.connector.CoyoteInputStream.read(CoyoteInputStream.java:132)
at com.fasterxml.jackson.core.json.UTF8StreamJsonParser._loadMore(UTF8StreamJsonParser.java:205)
at com.fasterxml.jackson.core.json.UTF8StreamJsonParser._loadMoreGuaranteed(UTF8StreamJsonParser.java:2342)
at com.fasterxml.jackson.core.json.UTF8StreamJsonParser._finishString2(UTF8StreamJsonParser.java:2427)
at com.fasterxml.jackson.core.json.UTF8StreamJsonParser._finishAndReturnString(UTF8StreamJsonParser.java:2407)
at com.fasterxml.jackson.core.json.UTF8StreamJsonParser.getText(UTF8StreamJsonParser.java:269)
at com.fasterxml.jackson.databind.deser.std.BaseNodeDeserializer.deserializeObject(JsonNodeDeserializer.java:264)
at com.fasterxml.jackson.databind.deser.std.BaseNodeDeserializer.deserializeArray(JsonNodeDeserializer.java:434)
at com.fasterxml.jackson.databind.deser.std.BaseNodeDeserializer.deserializeObject(JsonNodeDeserializer.java:258)
at com.fasterxml.jackson.databind.deser.std.BaseNodeDeserializer.deserializeArray(JsonNodeDeserializer.java:434)
at com.fasterxml.jackson.databind.deser.std.JsonNodeDeserializer.deserialize(JsonNodeDeserializer.java:70)
at com.fasterxml.jackson.databind.deser.std.JsonNodeDeserializer.deserialize(JsonNodeDeserializer.java:15)
at com.fasterxml.jackson.databind.deser.impl.MethodProperty.deserializeAndSet(MethodProperty.java:129)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.vanillaDeserialize(BeanDeserializer.java:288)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:151)
at com.fasterxml.jackson.databind.deser.std.CollectionDeserializer.deserialize(CollectionDeserializer.java:286)
at com.fasterxml.jackson.databind.deser.std.CollectionDeserializer.deserialize(CollectionDeserializer.java:245)
at com.fasterxml.jackson.databind.deser.std.CollectionDeserializer.deserialize(CollectionDeserializer.java:27)
at com.fasterxml.jackson.databind.deser.impl.MethodProperty.deserializeAndSet(MethodProperty.java:129)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.vanillaDeserialize(BeanDeserializer.java:288)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:151)
at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4014)
at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3071)
at com.myapp.controller.MyController.populate(PublishController.java:69)
at sun.reflect.GeneratedMethodAccessor140.invoke(UnkNown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.web.method.support.invocableHandlerMethod.doInvoke(invocableHandlerMethod.java:190)
at org.springframework.web.method.support.invocableHandlerMethod.invokeForRequest(invocableHandlerMethod.java:138)
at org.springframework.web.servlet.mvc.method.annotation.ServletinvocableHandlerMethod.invokeAndHandle(ServletinvocableHandlerMethod.java:105)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:893)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:798)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
at org.springframework.web.servlet.dispatcherServlet.dodispatch(dispatcherServlet.java:1040)
at org.springframework.web.servlet.dispatcherServlet.doService(dispatcherServlet.java:943)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:660)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at com.myapp.security.SecurityFilter.doFilterInternal(SecurityOAuthFilter.java:174)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.boot.actuate.web.trace.servlet.HttpTraceFilter.doFilterInternal(HttpTraceFilter.java:88)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.CorsFilter.doFilterInternal(CorsFilter.java:97)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.boot.actuate.metrics.web.servlet.WebMvcmetricsFilter.filterandRecordMetrics(WebMvcmetricsFilter.java:114)
at org.springframework.boot.actuate.metrics.web.servlet.WebMvcmetricsFilter.doFilterInternal(WebMvcmetricsFilter.java:104)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:367)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1639)
at org.apache.tomcat.util.net.socketProcessorBase.run(SocketProcessorBase.java:49)
- locked <0x0000000776284588> (a org.apache.tomcat.util.net.NioEndpoint$NioSocketWrapper)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:748)
近200个nio线程处于同一状态。可以采取哪些措施使代码更具可扩展性，从而获得更高的吞吐量。
解决方法
好的，所以如果我正确读取了堆栈跟踪，这是一个正在处理 Servlet 请求的工作线程，它在您的 populate 类中对 MyController 的调用中被阻塞。 populate 方法似乎是从从 HTTP 连接读取的流中反序列化 JSON。我不确定这是来自原始请求的 POST 数据，还是来自发送到后端服务器的请求的响应数据。无论哪种方式...
如果您有很多线程处于这种状态，最可能的问题是：
-
获取 JSON 的网络路径上存在网络拥塞。
-
您读取数据的来源跟不上。
-
您的服务器跟不上。
没有灵丹妙药可以让这样的服务更具可扩展性。可能的解决方案可能包括：
- 增加前端（或后端）网络带宽。
- 调整通信堆栈；例如按照 Andreas1 的建议使用 APR。
- 复制前端服务器并在其前面放置一个负载均衡器。
- 提高后端服务的性能。
- 调查更改您的应用程序设计，以便无需在前端与用户和/或后端与前端之间传递如此多的数据。
- 调查缓存是否会减少前端/后端流量。
- 如果瓶颈是 CPU 而不是 I/O，请考虑用序列化/反序列化开销较低的表示替换 JSON。
但在尝试应用解决方案之前，您首先需要了解系统中的实际瓶颈是什么。只有你能做到...
1 - 但是，如果您有 200 个线程像这样卡住，我很确定 APR 只能帮助您解决当前的可扩展性问题。当然，它不会让你更上一层楼。