HikariCP 不是 cleaning/using 互联网重新连接后的第一个 Oracle 数据库会话

Question

我在使用桌面 JavaFX 应用程序时遇到 HikariCP 与 Oracle 数据库的连接问题。

堆栈：

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

当尝试进行数据库查询时 WiFi 互联网连接丢失时，Hikari 指出：

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

并且在 WiFi 重新连接后，它不再使用相同的连接，Oracle 数据库上的会话仍然存在（未关闭，因为互联网丢失），但创建了新连接：

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 创建了新连接，在 Oracle 中我看到了同一个应用程序的 2 个会话。关闭 JavaFX 应用程序后第一个会话不会清除。第二个在出口处被清理。我可以做些什么来清理第一个会话？这是 Hikari 问题还是数据库问题？

这是Hikari配置，主要是默认：

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

并且 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，直到它被其配置文件明确杀死或超时。本质上它是在等待原来的客户端再发送一个网络包给它，这样它就可以通知客户端会话已经死了，然后退出。第二个会话干净地退出，因为您的应用程序发出了明确的注销命令。 DBA 需要配置用户的配置文件以限制空闲时间并清理会话。看这里：

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

HikariCP 不是 cleaning/using 互联网重新连接后的第一个 Oracle 数据库会话

HikariCP not cleaning/using first Oracle db session after internet reconnect

java

oracle

jdbc

hikaricp