HikariCP不清理/在互联网重新连接后使用第一个Oracle数据库会话

Question

我在使用桌面JavaFX应用程序时，与Oracle数据库的HikariCP连接有问题。

堆栈：

Java 8 / JavaFX 8
HikariCP 3.4.2
Oracle Database 11g Release 2
DB driver: ojdbc8 19.3.0.0

当尝试进行db查询时WiFi互联网连接丢失时，Hikari声明：

11:09:50.551 DEBUG [HikariPool-1 connection closer] com.zaxxer.hikari.pool.PoolBase: HikariPool-1 - 
    Closing connection oracle.jdbc.driver.T4CConnection@175d7635: (connection is dead)
    11:10:15.513 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.pool.HikariPool: HikariPool-1 - Timeout failure stats (total=0, active=0, idle=0, waiting=0)
    java.sql.SQLTransientConnectionException: HikariPool-1 - Connection is not available, request timed out after 30002ms.
11:10:19.606 DEBUG [HikariPool-1 housekeeper] com.zaxxer.hikari.pool.HikariPool: HikariPool-1 - Pool stats (total=0, active=0, idle=0, waiting=0)
11:10:32.569 DEBUG [HikariPool-1 connection adder] com.zaxxer.hikari.pool.HikariPool: HikariPool-1 - Cannot acquire connection from data source

在WiFi重新连接后，它不使用相同的连接，Oracle数据库上的会话是活的（没有关闭互联网丢失的原因），但创建新的连接：

11:10:48.320 DEBUG [HikariPool-1 connection adder] com.zaxxer.hikari.pool.HikariPool: HikariPool-1 - Added connection oracle.jdbc.driver.T4CConnection@20c1491b
11:10:49.608 DEBUG [HikariPool-1 housekeeper] com.zaxxer.hikari.pool.HikariPool: HikariPool-1 - Pool stats (total=1, active=0, idle=1, waiting=0)

所以Hikari创建了新的连接，在Oracle中，我看到了两个相同应用程序的会话。关闭JavaFX应用程序后，第一个会话不会清除。第二个在出口清理。我能做些什么来清洁第一个疗程？这是Hikari问题还是db问题？

这是Hikari配置，主要是默认配置：

11:09:17.754 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: HikariPool-1 - configuration:
11:09:17.759 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: allowPoolSuspension.............false
11:09:17.759 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: autoCommit......................true
11:09:17.760 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: catalog.........................none
11:09:17.760 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: connectionInitSql...............none
11:09:17.760 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: connectionTestQuery.............none
11:09:17.760 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: connectionTimeout...............30000
11:09:17.760 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: dataSource......................none
11:09:17.761 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: dataSourceClassName.............none
11:09:17.761 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: dataSourceJNDI..................none
11:09:17.761 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: dataSourceProperties............{password=<masked>, prepStmtCacheSqlLimit=2048, cachePrepStmts=true, prepStmtCacheSize=250}
11:09:17.762 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: driverClassName.................none
11:09:17.762 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: healthCheckProperties...........{}
11:09:17.762 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: healthCheckRegistry.............none
11:09:17.762 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: idleTimeout.....................600000
11:09:17.762 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: initializationFailTimeout.......1
11:09:17.763 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: isolateInternalQueries..........false
11:09:17.763 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: jdbcUrl.........................jdbc:oracle:thin:@xxx
11:09:17.763 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: leakDetectionThreshold..........20000
11:09:17.763 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: maxLifetime.....................1800000
11:09:17.763 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: maximumPoolSize.................1
11:09:17.763 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: metricRegistry..................none
11:09:17.764 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: metricsTrackerFactory...........none
11:09:17.764 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: minimumIdle.....................1
11:09:17.764 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: password........................<masked>
11:09:17.764 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: poolName........................"HikariPool-1"
11:09:17.764 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: readOnly........................false
11:09:17.764 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: registerMbeans..................false
11:09:17.764 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: scheduledExecutor...............none
11:09:17.765 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: schema..........................none
11:09:17.765 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: threadFactory...................internal
11:09:17.765 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: transactionIsolation............default
11:09:17.765 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: username........................"xxx"
11:09:17.765 DEBUG [JavaFX Application Thread] com.zaxxer.hikari.HikariConfig: validationTimeout...............5000

Hikari中的每个连接都是使用try with resources块创建的，例如：

 String getValueFromDatabase(String sql) {
        String str = "";
        try (final Connection con = DataSource.getConnection();
             final PreparedStatement stm = createStatement(con, sql);
             final ResultSet rs = stm.executeQuery()) {
            final ResultSetMetaData md = rs.getMetaData();
            while (rs.next()) {
                str = Optional.ofNullable(rs.getString(1)).orElse("");
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return str;
    }

我这样做也是为了检查互联网是否仍然可用（WiFi可能会丢失），并在连接失败时显示弹出消息（例如DataSource.getConnection（）.isClosed（）？）。

Answer 1

原始会话已被孤立。它将在数据库中保持可见，但不会消耗资源，直到它的配置文件显式终止或超时。本质上，它是在等待原始客户机向其发送另一个网络数据包，以便通知客户机会话已结束，然后退出。第二个会话干净地退出，因为应用程序发出了一个显式的注销命令。DBA需要配置用户配置文件以限制空闲时间并清理会话。请看这里：

https://oracle-base.com/articles/misc/clearing-down-old-database-sessions