Oracle connection number settings

Detailed explanation of Oracle connection number setting

Oracle database is one of the most widely used relational database management systems in the world. Its high availability, scalability and excellent performance have always been favored by everyone. . In the operation and maintenance of Oracle database, setting the number of connections is a very important matter, which is related to the stability and response speed of the database. This article will discuss in detail the issues related to Oracle connection number setting.

1. What is the number of Oracle connections?

In Oracle database, connection refers to the communication interface established by the client program and the database server through the network protocol. It is the key to realizing data interaction between the client and the server. Each connection can be regarded as An independent conversation process. The number of Oracle connections refers to the maximum number of connections allowed at a certain point in time. That is, when a large number of client programs are connected to the database, the number of Oracle connections will play a very important role.

2. Why should we limit the number of Oracle connections?

As the application scale of the database and the number of users continue to grow, connection number management has become a very important issue. If all clients are allowed to connect to the database at the same time without restrictions, it will cause the network to be overloaded. , database response slows down and other issues. At the same time, too many connections may lead to excessive consumption of database resources, causing serious problems such as database downtime. Therefore, limiting the number of Oracle connections is an issue that must be considered in database operation and maintenance.

3. How to set the number of Oracle connections?

For setting the number of Oracle connections, you can usually consider the following aspects:

1. Modify the parameters of the Oracle server

You can modify the parameters of the Oracle server Parameters to set the upper limit of the number of connections, this is the simplest and most direct method. By modifying the following two parameters in the Oracle server parameter file, you can control the maximum number of connections to the server:

processes: refers to the maximum number of processes allowed when the Oracle database is started, which is set in the init.ora file , which can be modified using the ALTER SYSTEM statement and ranges from 1 to 20,000 processes.

sessions: refers to the number of concurrently connected sessions in the Oracle database, including running and waiting sessions. It can also be modified through the ALTER SYSTEM statement, and session_max can also be used instead in the parameter file.

2. Modify the client parameters

This method limits the number of connections to the entire system by limiting the number of client connections. The Oracle client provides a parameter called SQLNET.INBOUND_CONNECT_TIMEOUT, which can control the response time after receiving a request from the client. By setting this parameter, you can limit the number of client connections and avoid timeout errors when clients connect.

3. Strengthen database management

In order to better enable the connection number strategy, we need to master the connection request situation of the database, promptly discover the situation of too many connections, and conduct Handle accordingly. Oracle provides a variety of system-level views and commands that can be used to monitor and manage the number of database connections.

4. Issues that should be paid attention to when setting the number of connections

In the process of setting the number of connections, you need to pay attention to the following issues:

1. Reasonably evaluate the number of connections settings Impact: In different application scenarios, the limit on the maximum number of connections will have different impacts on the system. Therefore, when setting the maximum number of connections, the impact on the system needs to be fully evaluated and estimated.
2. Set according to actual needs: In different database application scenarios, the setting of the maximum number of connections should also be different. For example, for lightweight website applications, the upper limit of the number of connections may only need to be set to a few hundred connections to meet the needs.
3. Usually needs to be adjusted according to the hardware conditions of the server: If we find that the currently limited maximum number of processes or sessions cannot meet business needs, a common method is to increase the physical memory of the server, which can also improve the database connection performance.
4. Timely diagnosis of exceptions: If you find that the database cannot work normally after configuring the connection limit, you should take certain diagnostic measures in time to locate the problem, find out the problem and make corresponding repair measures.

5. Conclusion

In Oracle database operation and maintenance, the connection limit is a very important and basic issue. By appropriately setting the connection number parameters, you can not only protect the security and stability of the database, but also improve the performance of the system. This is one of the skills that every DBA must master. However, in the process of setting the number of connections, we need to reasonably evaluate and estimate the impact of the number of connections on the system, and make corresponding adjustments based on actual needs and the hardware parameters of the server. If an abnormality is found, the problem must be diagnosed and dealt with in a timely manner. I believe that as long as we take this issue seriously, we can make the management of Oracle database more efficient, simple and excellent.

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