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Testing Thread-Based Transaction Management in CAT

This test suite demonstrates thread handling and message tracing capabilities in the CAT monitoring system. It validates the creation and management of transactions across multiple threads while maintaining trace context and message correlation.

Test Coverage Overview

The test suite covers critical aspects of multi-threaded transaction handling in CAT.

Transaction creation and completion in main thread
Child thread message correlation using TraceContextHelper
Event logging with remote linking capabilities
Message ID propagation across threads

Implementation Analysis

The testing approach utilizes JUnit to verify thread-safe transaction handling and message correlation. The implementation employs the Unidal thread management framework alongside CAT’s transaction and event tracking system.

Uses Cat.newTransaction() for transaction boundaries
Implements TraceContextHelper for message ID management
Leverages Threads.forGroup() for controlled thread execution

Technical Details

JUnit test framework
CAT monitoring system APIs
Unidal thread management library
Transaction and Event message types
TraceContextHelper for context propagation
Thread sleep for execution timing control

Best Practices Demonstrated

The test exemplifies robust concurrent testing practices with proper transaction management and context propagation.

Clean separation of thread execution logic
Proper transaction lifecycle management
Explicit message correlation across threads
Structured error handling and resource cleanup

dianping/cat

cat-home/src/test/java/com/dianping/cat/demo/ThreadTest.java

            
/*
 * Copyright (c) 2011-2018, Meituan Dianping. All Rights Reserved.
 *
 * 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 com.dianping.cat.demo;

import org.junit.Test;
import org.unidal.helper.Threads;

import com.dianping.cat.Cat;
import com.dianping.cat.message.Event;
import com.dianping.cat.message.Transaction;
import com.dianping.cat.message.context.TraceContextHelper;

public class ThreadTest {

	@Test
	public void test() throws InterruptedException {
		Transaction t = Cat.newTransaction("test3", "test3");

		String id = TraceContextHelper.createMessageId();

		Threads.forGroup("cat").start(new Task(id));

		Cat.logEvent("RemoteLink", "ChildThread3", Event.SUCCESS, id);

		t.complete();

		Thread.sleep(1000);
	}

	public static class Task implements Runnable {

		private String m_messageId;

		public Task(String id) {
			m_messageId = id;
		}

		@Override
		public void run() {

			Transaction t = Cat.newTransaction("test2", "test2");

			TraceContextHelper.threadLocal().getMessageTree().setMessageId(m_messageId);

			t.complete();
		}
	}
}