第258集CPU飙升，使用Arthas，3秒定位问题架构实战：Arthas诊断、性能分析与企业级故障快速定位设计

/**
 * 线程分析实战示例
 */
public class ThreadAnalysisExample {

    private final ExecutorService executor = Executors.newFixedThreadPool(10);
    private final Object lock = new Object();

    /**
     * 模拟CPU密集型任务
     */
    public void cpuIntensiveTask() {
        executor.submit(() -> {
            while (true) {
                // CPU密集型计算
                long result = 0;
                for (int i = 0; i < 1000000; i++) {
                    result += Math.sqrt(i);
                }

                // 模拟业务处理
                try {
                    Thread.sleep(100);
                } catch (InterruptedException e) {
                    Thread.currentThread().interrupt();
                    break;
                }
            }
        });
    }

    /**
     * 模拟阻塞任务
     */
    public void blockingTask() {
        executor.submit(() -> {
            synchronized (lock) {
                try {
                    // 长时间持有锁
                    Thread.sleep(10000);
                } catch (InterruptedException e) {
                    Thread.currentThread().interrupt();
                }
            }
        });
    }

    /**
     * 模拟死锁
     */
    public void deadlockTask() {
        Object lock1 = new Object();
        Object lock2 = new Object();

        executor.submit(() -> {
            synchronized (lock1) {
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    Thread.currentThread().interrupt();
                }
                synchronized (lock2) {
                    // 死锁场景
                }
            }
        });

        executor.submit(() -> {
            synchronized (lock2) {
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    Thread.currentThread().interrupt();
                }
                synchronized (lock1) {
                    // 死锁场景
                }
            }
        });
    }
}

/**
 * CPU密集型任务示例
 */
@Service
public class CpuIntensiveService {

    /**
     * 模拟CPU密集型计算
     */
    public void cpuIntensiveCalculation() {
        while (true) {
            // 复杂的数学计算
            double result = 0;
            for (int i = 0; i < 1000000; i++) {
                result += Math.sqrt(i) * Math.sin(i) * Math.cos(i);
            }

            // 模拟业务处理
            try {
                Thread.sleep(10);
            } catch (InterruptedException e) {
                Thread.currentThread().interrupt();
                break;
            }
        }
    }

    /**
     * 模拟无限循环
     */
    public void infiniteLoop() {
        while (true) {
            // 无限循环，消耗CPU
            int count = 0;
            for (int i = 0; i < Integer.MAX_VALUE; i++) {
                count++;
                if (count % 1000000 == 0) {
                    // 每100万次输出一次
                    System.out.println("Count: " + count);
                }
            }
        }
    }

    /**
     * 模拟递归调用
     */
    public long recursiveCalculation(int n) {
        if (n <= 1) {
            return 1;
        }
        return recursiveCalculation(n - 1) + recursiveCalculation(n - 2);
    }
}

/**
 * 问题代码分析
 */
public class ProblematicCode {

    /**
     * 问题1：无限循环
     */
    public void infiniteLoop() {
        while (true) {
            // 没有退出条件的循环
            doSomething();
        }
    }

    /**
     * 问题2：低效算法
     */
    public void inefficientAlgorithm() {
        // O(n²)复杂度的算法
        for (int i = 0; i < 10000; i++) {
            for (int j = 0; j < 10000; j++) {
                // 重复计算
                calculateSomething(i, j);
            }
        }
    }

    /**
     * 问题3：频繁GC
     */
    public void frequentGC() {
        List<String> list = new ArrayList<>();
        for (int i = 0; i < 1000000; i++) {
            // 频繁创建对象
            list.add("String " + i);
        }
    }

    /**
     * 问题4：阻塞操作
     */
    public void blockingOperation() {
        try {
            // 阻塞式IO操作
            Thread.sleep(10000);
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
        }
    }
}

/**
 * 优化后的代码
 */
public class OptimizedCode {

    /**
     * 优化1：添加退出条件
     */
    public void optimizedLoop() {
        boolean shouldContinue = true;
        while (shouldContinue) {
            doSomething();
            // 添加退出条件
            if (System.currentTimeMillis() > someTimestamp) {
                shouldContinue = false;
            }
        }
    }

    /**
     * 优化2：使用高效算法
     */
    public void efficientAlgorithm() {
        // 使用O(n)复杂度的算法
        Map<Integer, Integer> cache = new HashMap<>();
        for (int i = 0; i < 10000; i++) {
            // 使用缓存避免重复计算
            Integer result = cache.get(i);
            if (result == null) {
                result = calculateSomething(i);
                cache.put(i, result);
            }
        }
    }

    /**
     * 优化3：减少对象创建
     */
    public void reducedObjectCreation() {
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < 1000000; i++) {
            // 使用StringBuilder减少对象创建
            sb.append("String ").append(i);
        }
    }

    /**
     * 优化4：使用异步操作
     */
    public void asyncOperation() {
        CompletableFuture.runAsync(() -> {
            // 异步执行耗时操作
            doTimeConsumingWork();
        });
    }
}

/**
 * 自定义CPU分析命令
 */
@Name("cpu-analyzer")
@Description("CPU分析命令")
public class CpuAnalyzerCommand extends AnnotatedCommand {

    @Option(shortName = "t", longName = "time", description = "分析时间（秒）")
    private int time = 30;

    @Option(shortName = "f", longName = "file", description = "输出文件")
    private String file = "/tmp/cpu_analysis.txt";

    @Override
    public void process(CommandProcess process) {
        try {
            // 启动CPU分析
            process.write("Starting CPU analysis...\n");

            // 收集线程信息
            List<ThreadInfo> threads = getThreadInfo();

            // 分析CPU使用情况
            CpuAnalysisResult result = analyzeCpuUsage(threads);

            // 生成报告
            generateReport(result, file);

            process.write("CPU analysis completed. Report saved to: " + file + "\n");

        } catch (Exception e) {
            process.write("Error: " + e.getMessage() + "\n");
        }
    }

    private List<ThreadInfo> getThreadInfo() {
        // 获取线程信息
        ThreadMXBean threadBean = ManagementFactory.getThreadMXBean();
        return Arrays.asList(threadBean.getThreadInfo(threadBean.getAllThreadIds()));
    }

    private CpuAnalysisResult analyzeCpuUsage(List<ThreadInfo> threads) {
        CpuAnalysisResult result = new CpuAnalysisResult();

        // 分析CPU使用情况
        for (ThreadInfo thread : threads) {
            if (thread.getThreadState() == Thread.State.RUNNABLE) {
                result.addRunnableThread(thread);
            }
        }

        return result;
    }

    private void generateReport(CpuAnalysisResult result, String file) {
        try (PrintWriter writer = new PrintWriter(new FileWriter(file))) {
            writer.println("CPU Analysis Report");
            writer.println("==================");
            writer.println("Analysis Time: " + new Date());
            writer.println("Runnable Threads: " + result.getRunnableThreads().size());

            for (ThreadInfo thread : result.getRunnableThreads()) {
                writer.println("Thread: " + thread.getThreadName() + 
                             ", State: " + thread.getThreadState());
            }
        } catch (IOException e) {
            throw new RuntimeException("Failed to generate report", e);
        }
    }
}

/**
 * 自定义命令注册
 */
@Component
public class CustomCommandRegistry {

    @PostConstruct
    public void registerCustomCommands() {
        // 注册自定义命令
        CommandRegistry.getInstance().registerCommand(new CpuAnalyzerCommand());
    }
}

/**
 * Arthas与Prometheus集成
 */
@Component
public class ArthasPrometheusIntegration {

    @Autowired
    private MeterRegistry meterRegistry;

    /**
     * 收集Arthas指标
     */
    @Scheduled(fixedRate = 30000)
    public void collectArthasMetrics() {
        try {
            // 获取线程信息
            ThreadMXBean threadBean = ManagementFactory.getThreadMXBean();
            ThreadInfo[] threads = threadBean.getThreadInfo(threadBean.getAllThreadIds());

            // 统计线程状态
            Map<Thread.State, Long> threadStateCount = Arrays.stream(threads)
                    .collect(Collectors.groupingBy(
                            ThreadInfo::getThreadState,
                            Collectors.counting()));

            // 记录指标
            for (Map.Entry<Thread.State, Long> entry : threadStateCount.entrySet()) {
                Gauge.builder("arthas.threads.state")
                        .description("线程状态统计")
                        .tag("state", entry.getKey().name())
                        .register(meterRegistry, () -> entry.getValue());
            }

            // 记录CPU使用率
            double cpuUsage = getCpuUsage();
            Gauge.builder("arthas.cpu.usage")
                    .description("CPU使用率")
                    .register(meterRegistry, () -> cpuUsage);

        } catch (Exception e) {
            log.error("收集Arthas指标失败", e);
        }
    }

    private double getCpuUsage() {
        // 获取CPU使用率
        OperatingSystemMXBean osBean = ManagementFactory.getOperatingSystemMXBean();
        return osBean.getProcessCpuLoad() * 100;
    }
}