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配置单元JDBC-getConnection失败时连接泄漏

connection-leaks database-connection hive jdbc java

0

yelliver · 技术社区 · 6 年前

https://www.cloudera.com/downloads/connectors/hive/jdbc/2-6-2.html

有时,当调用getConnection()失败时(并不总是,取决于服务器的稳定性),它会显示以下异常:

MyDAO - Cannot create connection from DataSource@21f421b8 
at com.cloudera.hiveserver2.hivecommon.api.HS2Client.closeSession(Unknown Source)
at com.cloudera.hiveserver2.hivecommon.core.HiveJDBCCommonConnection.establishConnection(Unknown Source)
at com.cloudera.hiveserver2.jdbc.core.LoginTimeoutConnection.connect(Unknown Source)
at com.cloudera.hiveserver2.jdbc.common.BaseConnectionFactory.doConnect(Unknown Source)
at com.cloudera.hiveserver2.jdbc.common.AbstractDataSource.getSimbaConnection(Unknown Source)
at com.cloudera.hiveserver2.jdbc.common.AbstractDataSource.getConnection(Unknown Source)

当我用netstat命令检查时:

netstat -an --tcp --program

问题是:

为什么当我调用getConnection()时,会调用closeSession()?
是因为closeSession()失败,无法释放tcp连接吗?是否认为是连接泄漏?

0 回复 | 直到 6 年前

1

0

yelliver 6 年前

我反编译了驱动程序,检查H2SClient类:

public void closeSession() throws ErrorException {
    if (this.m_hasOpenSession) {
        try {
            TCloseSessionReq var1 = new TCloseSessionReq();
            var1.setSessionHandle(this.m_openSessionResp.getSessionHandle());
            this.m_client.CloseSession(var1);
            if (null != this.m_client && null != this.m_client.getInputProtocol() && null != this.m_client.getInputProtocol().getTransport()) {
                this.m_client.getInputProtocol().getTransport().close(); //line 8
            }

            this.m_hasOpenSession = false;
        } catch (Exception var3) {
            ErrorException var2 = HiveJDBCCommonDriver.s_HiveMessages.createGeneralException(HiveJDBCMessageKey.CONN_SESSION_ERR.name(), "Close Session Error");
            var2.initCause(var3);
            throw var2;
        }
    }

}

在catch块或finally块中也应调用该关闭:

public void closeSession() throws ErrorException {
    if (this.m_hasOpenSession) {
        try {
            TCloseSessionReq var1 = new TCloseSessionReq();
            var1.setSessionHandle(this.m_openSessionResp.getSessionHandle());
            this.m_client.CloseSession(var1);

            var2.initCause(var3);
            throw var2;
        } finally {
            if (null != this.m_client && null != this.m_client.getInputProtocol() && null != this.m_client.getInputProtocol().getTransport()) {
                this.m_client.getInputProtocol().getTransport().close(); //line 8
            }   
        }
    }
}