如何调试/记录Tomcat JDBC连接池的连接？

Question

我正在使用Tomcat JDBC连接池以及Spring启动,JDBC模板和SQL Server.当应用程序等待数据库连接时,我需要知道连接池内部的内容.如....

• 没有活动连接
• 没有空闲连接
• 没有被阻止的连接,其他信息阻止此连接的原因
• 没有可用的连接
• 和......

有没有办法通过调试或使用log4j等日志框架来获取这些信息？

任何想法将不胜感激.

Answer 1

经过大量的研究,我能够找到3种方法来记录和监控数据库连接池.

https://tomcat.apache.org/tomcat-8.0-doc/jdbc-pool.html

1. 使用Spring Boot 属性进行监视.

2. 使用JMX(Java Management Extensions)进行监控(如@nitin建议的那样)

3. 使用Spring Aspects进行监控.

第一种方式:使用Spring Boot属性进行监控.

我发现下面的Spring引导属性对于记录和监视数据库连接池非常有用.

这些属性(以及更多属性)没有记录.有关详细信息,请参阅下面的github问题. https://github.com/spring-projects/spring-boot/issues/1829

#Maximum no.of active connections
spring.datasource.max-active=10

#Log the stack trace of abandoned connection
spring.datasource.log-abandoned=true

#Remove abandoned connection,So, new connection will be created and made available to threads which are waiting for DB connection
spring.datasource.remove-abandoned=true

#If any connection is not used for 10 seconds, consider that connection as "abandoned"
spring.datasource.remove-abandoned-timeout=10 

#Number of ms to wait before throwing an exception if no connection is available.
spring.datasource.max-wait=1000

此列表包含更多仅与数据源相关的属性.(取自上面的链接)

spring.datasource.abandon-when-percentage-full
spring.datasource.access-to-underlying-connection-allowed
spring.datasource.alternate-username-allowed
spring.datasource.auto-commit
spring.datasource.catalog
spring.datasource.commit-on-return
spring.datasource.connection-customizer
spring.datasource.connection-customizer-class-name
spring.datasource.connection-init-sql
spring.datasource.connection-init-sqls
spring.datasource.connection-properties
spring.datasource.connection-test-query
spring.datasource.connection-timeout
spring.datasource.data-source
spring.datasource.data-source-class-name
spring.datasource.data-source-j-n-d-i
spring.datasource.data-source-properties
spring.datasource.db-properties
spring.datasource.default-auto-commit
spring.datasource.default-catalog
spring.datasource.default-read-only
spring.datasource.default-transaction-isolation
spring.datasource.driver-class-loader
spring.datasource.fair-queue
spring.datasource.idle-timeout
spring.datasource.ignore-exception-on-pre-load
spring.datasource.init-s-q-l
spring.datasource.initialization-fail-fast
spring.datasource.isolate-internal-queries
spring.datasource.jdbc-interceptors
spring.datasource.jdbc-url
spring.datasource.jdbc4-connection-test
spring.datasource.leak-detection-threshold
spring.datasource.log-abandoned
spring.datasource.log-validation-errors
spring.datasource.log-writer
spring.datasource.login-timeout
spring.datasource.max-age
spring.datasource.max-lifetime
spring.datasource.max-open-prepared-statements
spring.datasource.maximum-pool-size
spring.datasource.metrics-tracker-class-name
spring.datasource.minimum-idle
spring.datasource.num-tests-per-eviction-run
spring.datasource.pool-name
spring.datasource.pool-prepared-statements
spring.datasource.pool-properties
spring.datasource.propagate-interrupt-state
spring.datasource.read-only
spring.datasource.record-metrics
spring.datasource.register-mbeans
spring.datasource.remove-abandoned
spring.datasource.remove-abandoned-timeout
spring.datasource.rollback-on-return
spring.datasource.suspect-timeout
spring.datasource.test-on-connect
spring.datasource.thread-factory
spring.datasource.transaction-isolation
spring.datasource.use-disposable-connection-facade
spring.datasource.use-equals
spring.datasource.use-lock
spring.datasource.validation-interval
spring.datasource.validation-query-timeout
spring.datasource.validator
spring.datasource.validator-class-name
spring.datasource.xa
spring.datasource.xa.data-source-class-name
spring.datasource.xa.properties

第二种方式:使用JMX进行监控(Java Management Extensions)

Tomcat JDBC池提供了一个MBean,即ConnectionPoolMBean.

https://tomcat.apache.org/tomcat-7.0-doc/api/org/apache/tomcat/jdbc/pool/jmx/ConnectionPoolMBean.html

Spring Boot自动注册JMX MBean.因此,无需将此MBean注册/导出到MBean服务器.只需打开JDK附带的JConsole,打开,在Windows->命令提示符 - > jconsole,就是这样.有关详情,请参阅下面的屏幕截

每当连接被放弃,连接失败,查询花费很长时间等时,此MBean也会通知.请参阅下面的屏幕截图.

第三种方式:使用Spring方面进行监控(仅适用于开发/ QA环境).

我使用此方面来记录TomcatJdbc连接池.

我创建了一个Spring Aspect,它将拦截每个数据库调用.这肯定会影响性能.

因此,在开发/ QA环境中使用此方面,在不需要时注释掉此方法(例如:在生产部署期间).

@Before("execution(* com.test.app.db.dao.*.*(..))")
    public void logBeforeConnection(JoinPoint jp) throws Throwable {
        String methodName = "";
        methodName += jp.getTarget().getClass().getName();
        methodName += ":";
        methodName += jp.getSignature().getName();
        logger.info("before method call : " + methodName +  " : number of connections in use by the application (active) : "+ tomcatJdbcPoolDataSource.getNumActive());
        logger.info("before method call : " + methodName +  " : the number of established but idle connections : "+ tomcatJdbcPoolDataSource.getNumIdle());
        logger.info("before method call : " + methodName +  " : number of threads waiting for a connection : "+ tomcatJdbcPoolDataSource.getWaitCount());
    }


@After("execution(* com.test.app.db.dao.*.*(..)) ")
public void logAfterConnection(JoinPoint jp) throws Throwable {
    String methodName = "";
    methodName += jp.getTarget().getClass().getName();
    methodName += ":";
    methodName += jp.getSignature().getName();
    logger.info("after method call : " + methodName +  " : number of connections in use by the application (active) : "+ tomcatJdbcPoolDataSource.getNumActive());
    logger.info("after method call : " + methodName +  " : the number of established but idle connections : "+ tomcatJdbcPoolDataSource.getNumIdle());
    logger.info("after method call : " + methodName +  " : number of threads waiting for a connection : "+ tomcatJdbcPoolDataSource.getWaitCount());
    //tomcatJdbcPoolDataSource.checkAbandoned();
}

现在,您可以轻松识别在应用程序中创建连接泄漏的特定数据库调用.

Answer 2

感谢@Sundararaj Govindasamy 的精彩回答。基于它，我在我的 Spring Boot 应用程序中创建了一个组件来调试我的数据库池信息。

import org.apache.tomcat.jdbc.pool.DataSource;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.After;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

@Aspect
@Component
public class DataSourceAspectLogger {

    protected final Logger logger = LoggerFactory.getLogger(this.getClass());

    @Autowired
    private DataSource ds;

    @Before("execution(* br.com.foo.core.repository.*.*(..))")
    public void logBeforeConnection(JoinPoint jp) throws Throwable {
        logDataSourceInfos("Before", jp);
    }

    @After("execution(* br.com.foo.core.repository.*.*(..)) ")
    public void logAfterConnection(JoinPoint jp) throws Throwable {
        logDataSourceInfos("After", jp);
    }

    public void logDataSourceInfos(final String time, final JoinPoint jp) {
        final String method = String.format("%s:%s", jp.getTarget().getClass().getName(), jp.getSignature().getName());
        logger.info(String.format("%s %s: number of connections in use by the application (active): %d.", time, method, ds.getNumActive()));
        logger.info(String.format("%s %s: the number of established but idle connections: %d.", time, method, ds.getNumIdle()));
        logger.info(String.format("%s %s: number of threads waiting for a connection: %d.", time, method, ds.getWaitCount()));
    }
}