Number of IIS concurrent connections and database connection pool

One, database connection pool

1. Error:

The timeout period has expired. The timeout period has expired, but the connection has not been obtained from the pool. This can happen because all pooled connections are in use and the maximum pool size is reached.

2, problem analysis:

The problem is that the connection to the database does not appear to be closed, and the system is automatically reclaimed for a time.

3. Related knowledge:

The number of database connections, which is a database, that can accept at most one client connection at a time.
In the absence of a database connection pool, a client, each access, creates a database connection, executes the SQL, obtains the results, and then closes and releases the database connection. The problem is that creating a database connection is a resource-intensive operation that takes a lot of time. The database connection pool is then generated.
The database connection pool pre-opens a certain number of database connections and maintains the connection. When the client executes the SQL statement, it obtains a connection from the database connection pool, executes the SQL, obtains the result, and then returns the database connection to the database connection pool.
If a session, perform 10 independent operations. If you do not use a database connection pool, you need to create a database connection 10 times and close 10 times. Using a database connection pool, directly using the database connection pool is already open and ready to use.

4. Solution

A, in the code, the closed database connection shut down and release resources
b, expand the shared pool, the configuration file inside, the database connection plus
Max Pool size=512;server=local;uid=;p wd=;d atabase=2004;


Ii. number of IIS concurrent connections

1. Error:

HTTP 403.9-No access: too many users connected

2. Related knowledge:

IIS concurrent connections refers to the first request to the server xxx.html, and then will also request the Web page CSS, JS, pictures, etc., each request counted an IIS concurrency number. Simply put, a file is downloaded by a user, then from the beginning of the download to the end of the download, this period will continue to occupy 1 IIS connections.

Number of IIS concurrent connections and database connection pool