Datax rdbms task was blocking when query was killed

Datax rdbms task was blocking when query was killed

CommonRdbmsReader.
void startRead(){
........

while (rs.next()) {

rsNextUsedTime += (System.nanoTime() - lastTime);

this.transportOneRecord(recordSender, rs,
metaData, columnNumber, mandatoryEncoding, taskPluginCollector);

lastTime = System.nanoTime();

}
allResultPerfRecord.end(rsNextUsedTime);

//目前大盘是依赖这个打印，而之前这个Finish read record是包含了sql查询和result next的全部时间
LOG.info("Finished read record...");
//LOG.info("Finished read record by Sql: [{}\n] [{}\n] {}.",
//querySql, (bindVarsArr.isEmpty()?"":bindVarsArr.getJSONArray(idx)),basicMsg);

if(bindVarsArr.isEmpty())
{
LOG.info("Finished read record 1 ");
break;
}
else
{
//关闭游标
DBUtil.closeDBResources(rs, null, null);
idx++;
}
}
while(true);
}catch (Exception e) {
LOG.info("Finished read record with exception :{}" ,e);
throw RdbmsException.asQueryException(this.dataBaseType, e, querySql, table, username);
} finally {
LOG.info("Finished read record close connection 1...");
// 正在进行抽数时候，mysql 的query 被异常中断了，这里的 close connection 会导致阻塞
DBUtil.closeDBResources(null, conn);
LOG.info("Finished read record close connection 2...");
}
}

Start at CommonRdbmsReader.startRead and trace the finally block through DBUtil.closeDBResources(null, conn). Investigate the behavior when a MySQL query is interrupted or killed, focusing on why connection cleanup blocks. Done means the RDBMS task does not remain blocked during cleanup after an interrupted query.

Written by the indexing model from the issue text.