jmc线程转储_使线程转储智能化

jmc线程转储

很久以前，我了解了一个称为Log MDC的东西，我对此非常感兴趣。我突然意识到日志文件中发生的一切，并指出了特定的日志条目，并找到了对错，特别是在调试生产中的错误时。

2013年，我受委托从事一个项目，该项目正在经历一些麻烦的水域（几件事的结合），几乎每个星期我都必须经历几个Java线程转储，以弄清应用程序中发生的事情以使其停止。另外，有时候我不得不将诸如AppDynamic，jProfiler，jConsole之类的探查器全部连接到应用程序，以试图找出问题所在，更重要的是是什么引发了问题。 jStack是我曾经使用过的最有用的工具之一，但是颠簸的线程转储没有我可以使用的上下文信息。我被困在看到10（s）个转储，其中包含导致类的原因的类的堆栈跟踪，但是没有有关什么是什么以及导致问题的输入的信息，并且它很快就令人沮丧。最终，我们找到了问题，但是它们主要是经过几轮使用各种数据集进行的深度调试之后。

一旦完成该项目，我发誓我再也不会陷入那种境地了。我探索了可以使用类似于Log4j的NDC但在线程中使用它的方式，以便我的转储有意义。而且我发现我可以更改ThreadName。我的下一个项目确实非常有效地使用了它。我最近遇到了一篇文章，很好地解释了这个概念。我不会重写他们所说的所有内容，因此这里是他们博客文章的链接。

所以上周我开始一个新项目，当我开始编码框架时（使用Spring 4.1和Spring Boot），这是我为应用程序编写的第一个类，并确保过滤器尽快进入代码。帮助我们进行后期制作，但也使我的开发日志有意义。

下面是Log4j NDC和设置ThreadName的代码副本。

import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.filter.OncePerRequestFilter;/*** This is a very Spring opinionated HTTPFilter used for intercepting all requests and decorate the thread name with additional contextual* information. We have extenced the filter from {@link OncePerRequestFilter} class provided by Spring Framework to ensure that the filter is absolutely * executd only once per request. * * The following information will be added:* <ul>* <li>Old Thread name: to ensure that we are not losing any original context with thread names;</li>* <li>Time when the request was intercepted;</li>* <li>The RequestURI that proviced information on what RestFUL endpoint was accessed as part of this request;</li>* <li>A Token that was received in the header. This token is encrypted and does not exposes any confidential information. Also, this token provides* context which helps during debugging;</li>* <li>The Payload from the token. This information will be very helpful when we have to debug for issues that may be happening with a call request* as this holds all the information sent from the called.</li>* </ul>* * This filter will also reset the ThreadName back to it's original name once the processing is complete.* * @author Kapil Viren Ahuja**/
public class DecorateThreadNameFilter extends OncePerRequestFilter {@Overrideprotected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)throws ServletException, IOException {final Logger LOGGER = LoggerFactory.getLogger(DecorateThreadNameFilter.class);final SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");Thread thread = Thread.currentThread();String threadOriginalName = thread.getName();String uri = request.getRequestURI();String time = dateFormat.format(new Date());String token = request.getHeader("authorization");try {thread.setName(String.format("%s StartTime \"%s\" RequestURI \"%s\" Token \"%s\"", threadOriginalName, time, uri, token));} catch (Exception ex) {LOGGER.error("Failed to set the thread name.", ex);// this is an internal filter and an error here should not impact// the request processing, hence eat the exception}try {filterChain.doFilter(request, response);} finally {try {thread.setName(threadOriginalName);} catch (Exception ex) {LOGGER.error("Failed to reset the thread name.", ex);// this is an internal filter and an error here should not// impact the request processing, hence eat the exception}}}
}

/*** Generic filter for intercepting all requests and perform the following generic tasks:* * <ul>* <li>Intercepts the request and then pushed the user domain into the session if one exists.</li>* <li> Pushes a uniquely generated request identifier to the LOG4J NDC context. This identifier will then be prepended* to all log messages generated using LOG4J. This allows tracing all log messages generated as part of the same* request; </li>* <li> Pushes the HTTP session identifier to the LOG4J NDC context. This identifier will then be prepended to all log* messages generated using LOG4J. This allows tracing all log messages generated as part of the same HTTP session;* </li>* <li> Pushes the IP address of the client to the LOG4J NDC context. The IP address will then be prepended to all log* messages generated using LOG4J. This allows tying back multiple user sessions initiated with the same logon name to* be correctly tied back to their actual origins. </li>* </ul>*/
public class RequestInterceptorFilter implements Filter
{/*** <p>* <ul>* <li>Initializes the LOG4J NDC context before executing an HTTP requests.</li>* <li>Pushes the domain into the session</li>* </ul>* </p>*/public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException{HttpServletRequest httpRequest = (HttpServletRequest) request;if (httpRequest.isRequestedSessionIdFromCookie() && !httpRequest.isRequestedSessionIdValid()){// TODO: Need to define an session expiration page and redirect the application to that page// As of now this is a non-issue as we are handling session expirations on Flex (Front-end) and hence// no request will come to server in case the session timeout occurs// HttpServletResponse httpServletResponse = (HttpServletResponse) response;// httpServletResponse.sendRedirect(httpRequest.getContextPath() + "?expired");}else{// Create an NDC context string that will be prepended to all log messages written to files.org.apache.log4j.NDC.push(getContextualInformation(httpRequest));// Process the chain of filterschain.doFilter(request, response);// Clear the NDC context string so that if the thread is reused for another request, a new context string is// used.org.apache.log4j.NDC.remove();}}public void init(FilterConfig arg0) throws ServletException{}public void destroy(){}/*** <p>* Generates the Contextual information to be put in the log4j's context. This information helps in tracing requests* </p>* * @param httpRequest* @return*/private String getContextualInformation(HttpServletRequest httpRequest){String httpRequestIdentifier = UUID.randomUUID().toString();String httpSessionIdentifier = httpRequest.getSession().getId();String clientAddress = httpRequest.getRemoteAddr();StringBuffer logNDC = new StringBuffer(httpRequestIdentifier + " | " + httpSessionIdentifier + " | " + clientAddress);String userName = (String)httpRequest.getSession().getAttribute(WebConstants.USERNAME);if (userName != null){logNDC.append(" | " + userName);}String domain = (String)httpRequest.getSession().getAttribute(WebConstants.DOMAIN);if (domain != null){logNDC.append(" | " + domain);}// Create an NDC context string that will be prepended to all log messages written to files.return logNDC.toString();}
}