candyleer commented on a change in pull request #3173: [WIP] Java agent support undertow routing handler URL: https://github.com/apache/skywalking/pull/3173#discussion_r307989335
########## File path: apm-sniffer/apm-sdk-plugin/undertow-plugins/undertow-2.x-plugin/src/main/java/org/apache/skywalking/apm/plugin/undertow/v2x/RoutingHandlerInterceptor.java ########## @@ -0,0 +1,96 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + */ +package org.apache.skywalking.apm.plugin.undertow.v2x; + +import io.undertow.server.ExchangeCompletionListener; +import io.undertow.server.HttpHandler; +import io.undertow.server.HttpServerExchange; +import org.apache.skywalking.apm.agent.core.context.ContextManager; +import org.apache.skywalking.apm.agent.core.context.tag.Tags; +import org.apache.skywalking.apm.agent.core.context.trace.AbstractSpan; +import org.apache.skywalking.apm.agent.core.plugin.interceptor.enhance.EnhancedInstance; +import org.apache.skywalking.apm.agent.core.plugin.interceptor.enhance.InstanceMethodsAroundInterceptor; +import org.apache.skywalking.apm.agent.core.plugin.interceptor.enhance.MethodInterceptResult; +import org.apache.skywalking.apm.plugin.undertow.v2x.util.TraceContextUtils; + +import java.lang.reflect.Method; + +/** + * @author AI + * 2019-07-25 + */ +public class RoutingHandlerInterceptor implements InstanceMethodsAroundInterceptor { + + @Override + public void beforeMethod(EnhancedInstance objInst, Method method, Object[] allArguments, Class<?>[] argumentsTypes, MethodInterceptResult result) throws Throwable { + int httpHandlerIndex = -1; + for (int index = 0; index < allArguments.length; index++) { + Object any = allArguments[index]; + if (any instanceof HttpHandler) { + httpHandlerIndex = index; + break; + } + } + if (httpHandlerIndex > -1) { + HttpHandler handler = (HttpHandler) allArguments[httpHandlerIndex]; + String template = (String) allArguments[1]; + allArguments[httpHandlerIndex] = new TracingHandler(template, handler); + TraceContextUtils.enabledRoutingHandlerTracing(); + } + } + + @Override + public Object afterMethod(EnhancedInstance objInst, Method method, Object[] allArguments, Class<?>[] argumentsTypes, Object ret) throws Throwable { + return ret; + } + + @Override + public void handleMethodException(EnhancedInstance objInst, Method method, Object[] allArguments, Class<?>[] argumentsTypes, Throwable t) { + ContextManager.activeSpan().errorOccurred().log(t); + } + + private static class TracingHandler implements HttpHandler { + private final String template; + private final HttpHandler next; + + TracingHandler(String template, HttpHandler handler) { + this.next = handler; + this.template = template; + } + + @Override + public void handleRequest(HttpServerExchange exchange) throws Exception { + final AbstractSpan span = TraceContextUtils.buildUndertowEntrySpan(exchange, template); + exchange.addExchangeCompleteListener(new ExchangeCompletionListener() { + @Override + public void exchangeEvent(HttpServerExchange httpServerExchange, NextListener nextListener) { + if (httpServerExchange.getStatusCode() >= 400) { + span.errorOccurred(); + Tags.STATUS_CODE.set(span, Integer.toString(httpServerExchange.getStatusCode())); + } + span.asyncFinish(); + nextListener.proceed(); + } + }); + next.handleRequest(exchange); + span.prepareForAsync(); Review comment: `span.prepareForAsync();` should call before `next.handleRequest(exchange)` because in some low latency request, when `span.asyncFinish();` execute the `prepareForAsync` may not execute which may cause error. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
