1 BUG現(xiàn)象

系統(tǒng)并發(fā)請求，系統(tǒng)停滯無法使用，所有接口都是無法與后端進行交互的狀態(tài)，系統(tǒng)并沒有宕機

2 BUG的業(yè)務(wù)流程

1. 插入分數(shù)方法 涉及插入表ABCD 加了聲明式事務(wù)
2. 查詢分數(shù)方法 涉及表ABCD

controller() {
	@Transactional
	insertVo();
	selectById();
}

3 排查原因

因為代碼不是我寫的，一開始我就是懷疑是死鎖導致的BUG，然后我用Jconsole，去檢測一下死鎖，并沒有發(fā)現(xiàn)死鎖，接下來我去Mysql看有沒有死鎖，結(jié)果也沒有發(fā)現(xiàn)，然后我就懵了，jvm沒有鎖，mysql也沒有鎖且沒有SQL在執(zhí)行，為什么請求就會全注阻塞？

然后我去開始去看這個代碼了，我發(fā)現(xiàn)他在控制層調(diào)用了兩個業(yè)務(wù)層，通常我們只在控制層去做校驗去調(diào)用一個service啊，然后我就繼續(xù)看，insertVo插入了很多查詢了很多，耗時3秒鐘左右，selectById查詢了一條SQL，這兩個明面上的代碼并沒有什么加鎖或什么飛天操作，想了半天搞不懂為什么。

然后我開始用排除法，把這些代碼一一注釋調(diào)試一下。我把insertVo注釋掉，這個毋庸置疑，那只有一個簡單的操作了，就查一表返回，這個絕對是沒問題的，然后我把selectById注釋掉，居然就好了？,selectById只有一條查詢SQL啊也沒有加鎖，這個能解決但是肯定也不是這個原因。

然后我用druid監(jiān)控到可使用連接數(shù)一直在占用，沒有釋放，我就去查druid配置，發(fā)現(xiàn)配置了

initial-size: 20 #初始大小
min-idle: 20 #最小空閑
max-active: 40 #最大鏈接
max-wait: 10000 #配置獲取連接等待超時的時間

這個配置也沒有毛病啊，沒辦法了我只能去看線程的具體信息了，查出來所有的線程池連接線程都是這樣的

"pool-6-thread-10" #244 prio=5 os_prio=31 tid=0x00007fe94235f000 nid=0x22803 waiting on condition [0x00000003150ce000]
   java.lang.Thread.State: WAITING (parking)
	at sun.misc.Unsafe.park(Native Method)
	- parking to wait for  <0x00000006c109e090> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
	at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
	at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(AbstractQueuedSynchronizer.java:2039)
	at com.alibaba.druid.pool.DruidDataSource.takeLast(DruidDataSource.java:2315)
	at com.alibaba.druid.pool.DruidDataSource.getConnectionInternal(DruidDataSource.java:1781)
	at com.alibaba.druid.pool.DruidDataSource.getConnectionDirect(DruidDataSource.java:1494)
	at com.alibaba.druid.filter.FilterChainImpl.dataSource_connect(FilterChainImpl.java:5058)
	at com.alibaba.druid.filter.stat.StatFilter.dataSource_getConnection(StatFilter.java:704)
	at com.alibaba.druid.filter.FilterChainImpl.dataSource_connect(FilterChainImpl.java:5054)
	at com.alibaba.druid.filter.FilterAdapter.dataSource_getConnection(FilterAdapter.java:2759)
	at com.alibaba.druid.filter.FilterChainImpl.dataSource_connect(FilterChainImpl.java:5054)
	at com.alibaba.druid.pool.DruidDataSource.getConnection(DruidDataSource.java:1469)
	at com.alibaba.druid.pool.DruidDataSource.getConnection(DruidDataSource.java:1459)
	at com.alibaba.druid.pool.DruidDataSource.getConnection(DruidDataSource.java:83)
	at org.hibernate.engine.jdbc.connections.internal.DatasourceConnectionProviderImpl.getConnection(DatasourceConnectionProviderImpl.java:122)
	at org.hibernate.internal.NonContextualJdbcConnectionAccess.obtainConnection(NonContextualJdbcConnectionAccess.java:38)
	at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.acquireConnectionIfNeeded(LogicalConnectionManagedImpl.java:104)
	at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.getPhysicalConnection(LogicalConnectionManagedImpl.java:134)
	at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.getConnectionForTransactionManagement(LogicalConnectionManagedImpl.java:250)
	at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.begin(LogicalConnectionManagedImpl.java:258)
	at org.hibernate.resource.transaction.backend.jdbc.internal.JdbcResourceLocalTransactionCoordinatorImpl$TransactionDriverControlImpl.begin(JdbcResourceLocalTransactionCoordinatorImpl.java:246)
	at org.hibernate.engine.transaction.internal.TransactionImpl.begin(TransactionImpl.java:83)
	at org.springframework.orm.jpa.vendor.HibernateJpaDialect.beginTransaction(HibernateJpaDialect.java:184)
	at org.springframework.orm.jpa.JpaTransactionManager.doBegin(JpaTransactionManager.java:402)
	at org.springframework.transaction.support.AbstractPlatformTransactionManager.getTransaction(AbstractPlatformTransactionManager.java:376)
	at org.springframework.transaction.interceptor.TransactionAspectSupport.createTransactionIfNecessary(TransactionAspectSupport.java:572)
	at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:360)
	at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:99)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
	at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:747)
	at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:95)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
	at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:747)
	at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:689)
	at com.treach.platform.modules.service.impl.SysLogService$$EnhancerBySpringCGLIB$$36a85251.insert(<generated>)
	at com.treach.platform.log.factory.LogTaskFactory$2.run(LogTaskFactory.java:56)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(ScheduledThreadPoolExecutor.java:180)
	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:750)

   Locked ownable synchronizers:
	- <0x00000007741f0d68> (a java.util.concurrent.ThreadPoolExecutor$Worker)

是的，連接池連接一直被占用鎖住了，為什么會被鎖住呢？，也設(shè)置了連接等待超時時間啊，然后我懷疑是配置沒有生效，寫了個代碼看看

public static void main(String[] args) throws SQLException {
        ConfigurableApplicationContext run = SpringApplication.run(NdCyApplication.class, args);
        DruidDataSource bean = run.getBean(DruidDataSource.class);

        int maxActive = bean.getMaxActive();
        long maxWait = bean.getMaxWait();
        log.info("數(shù)據(jù)庫線程池與數(shù)據(jù)庫最大鏈接數(shù)" + String.valueOf(maxActive));
        log.info("數(shù)據(jù)庫線程池等待鏈接數(shù)超時時間"+String.valueOf(maxWait));
    }

結(jié)果：

數(shù)據(jù)庫線程池與數(shù)據(jù)庫最大鏈接數(shù)8
數(shù)據(jù)庫線程池等待鏈接數(shù)超時時間-1

這個和配置的不一樣啊，真的沒有生效，然后我又去查為什么沒有生效，原來配置類里面有個DataSoure

@Bean     //聲明其為Bean實例
@Primary  //在同樣的DataSource中，首先使用被標注的DataSource
@ConfigurationProperties(prefix = "spring.datasource")
public DruidDataSource dataSource(){
        DruidDataSource datasource = new DruidDataSource();
        List<Filter> filters = new ArrayList<>();
        filters.add(wallFilter);
        filters.add(new StatFilter());
        datasource.setProxyFilters(filters);
        return datasource;
}

我們applcation.yaml的配置被覆蓋了，druid默認等待鏈接數(shù)超時時間-1，難怪長時間占用連接沒有超時。

4 解決

把等待連接超時時間等設(shè)置上

@Bean     //聲明其為Bean實例
@Primary  //在同樣的DataSource中，首先使用被標注的DataSource
@ConfigurationProperties(prefix = "spring.datasource")
public DruidDataSource dataSource(){
        DruidDataSource datasource = new DruidDataSource();
        datasource.setInitialSize(20);
        datasource.setMaxActive(80);
        datasource.setMaxWait(5000);
        List<Filter> filters = new ArrayList<>();
        filters.add(wallFilter);
        filters.add(new StatFilter());
        datasource.setProxyFilters(filters);
        return datasource;
}

成功

5 不懂的點

為什么會出現(xiàn)不回收線程的情況 按理來說現(xiàn)在沒有SQL在執(zhí)行，連接數(shù)不是會被回收嗎 回到線程池 等待的線程就有連接了 就能不卡死了 為什么呢？文章來源地址http://www.zghlxwxcb.cn/news/detail-637536.html

到了這里，關(guān)于記錄一次解決數(shù)據(jù)庫連接池連接泄露BUG的文章就介紹完了。如果您還想了解更多內(nèi)容，請在右上角搜索TOY模板網(wǎng)以前的文章或繼續(xù)瀏覽下面的相關(guān)文章，希望大家以后多多支持TOY模板網(wǎng)！