[Bug] [connection] If it runs for a long time, there is a problem that the connection pool leaks and causes inaccessibility.

[Andy1i]

Search before asking

• [X] I had searched in the issues and found no similar issues.

Operating system information

Linux

Python version information

=3.11

DB-GPT version

main

Related scenes

• [ ] Chat Data
• [ ] Chat Excel
• [ ] Chat DB
• [ ] Chat Knowledge
• [ ] Model Management
• [ ] Dashboard
• [ ] Plugins

Installation Information

• [ ] Installation From Source

• [X] Docker Installation

• [ ] Docker Compose Installation

• [ ] Cluster Installation

• [ ] AutoDL Image

• [ ] Other

Device information

cpu: 16c 32g

Models information

default

What happened

1. 使用 get_raw_session 时， 大部分使用没有主动释放session, 导致连接池长时间占用
2. RDBMSConnector 类使用 self.session 或者 self._db_sessions 时，未进行主动释放， 导致连接被长时间占用

What you expected to happen

使用上述两个方法时， 是否需要主动释放session， 或者使用上下文 with来关联session， 避免造成session资源的浪费或泄露

How to reproduce

1. 将系统连接池变小
   • LOCAL_DB_POOL_SIZE=2
   • LOCAL_DB_POOL_OVERFLOW=0
     2. 将数据库连接时连接池变小进行测试

   • 

Additional context

No response

Are you willing to submit PR?

• [ ] Yes I am willing to submit a PR!