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Designing for Performance: What s Your Strategy in .NET Generator Data Matrix in .NET Designing for Performance: What s Your Strategy

Designing for Performance: What s Your Strategy using barcode encoding for .net framework control to generate, create datamatrix image in .net framework applications. Oracle Reports Get database version 2d Data Matrix barcode for .NET information. Establish the optimal database protocol packet size to be used for communication.

Set session settings. In addition, the database management system establishes resources on behalf of the connection, which involves performance-expensive disk I/O and memory allocation. You might be thinking that you can eliminate network round trips if you place your applications on the same machine as the database system.

This is, in most cases, not realistic because of the complexity of real-world enterprises many, many applications accessing many database systems with applications running on several application servers. In addition, the server on which the database system runs must be well tuned for the database system, not for many different applications. Even if one machine would fit the bill, would you really want a single point of failure Using Connection Pooling A connection pool is a cache of physical database connections that one or more applications can reuse.

Connection pooling can provide significant performance gains because reusing a connection reduces the overhead associated with establishing a physical connection. The caveat here is that your database server must have enough memory to manage all the connections in the pool. In this book, we discuss client-side connection pooling (connection pooling provided by database drivers and application servers), not database-side connection pooling (connection pooling provided by database management systems).

Some database management systems provide connection pooling, and those implementations work in conjunction with client-side connection pooling. Although specific characteristics of database-side connection pooling vary, the overall goal is to eliminate the overhead on the database server of establishing and removing connections. Unlike client-side connection pooling, database-side connection pooling does not optimize network round trips to the application.

As we stated previously, connecting to a database is performance-expensive because of the resource allocation in the database driver (network round trips between the driver and the database), and the resource allocation on the database server. Client-side connection pooling helps solve the issue of expensive resource allocation for both the database driver and database server. Database-side connection pooling only helps solve the issue on the database server.

. Your Applications How Connection Pooling Works In a pooled environmen t, once the initial physical connection is established, it will likely not be closed for the life of the environment. That is, when an application disconnects, the physical connection is not closed; instead, it is placed in the pool for reuse. Therefore, re-establishing the connection becomes one of the fastest operations instead of one of the slowest.

Here is a basic overview of how connection pooling works (as shown in Figure 2-1): 1. When the application or application server is started, the connection pool is typically populated with connections. 2.

An application makes a connection request. 3. Either the driver or the Connection Pool Manager (depending on your architecture) assigns one of the pooled connections to the application instead of requesting that a new connection be established.

This means that no network round trips occur between the driver and the database server for connection requests because a connection is available in the pool. The result: Your connection request is fast. 4.

The application is connected to the database. 5. When the connection is closed, it is placed back into the pool.

. Application Server 1. Application server started; connection pool is populated. Application Server Application 2. Application makes a connection request. 3.

A pooled connection is given to the application. 4. Application is connected to the database.

. Application Server Application 5. When the connection is closed, it is placed back into the pool. Figure 2-1. Connection pooling Designing for Performance: What s Your Strategy Guidelines for Connection Pooling Here are some general Data Matrix for .NET guidelines for using connection pooling. For details about different connection pooling models, see 8, Connection Pooling and Statement Pooling.

A perfect scenario for using connection pooling is when your applications reside on an application server, which implies multiple users using the applications. Consider using connection pooling if your application has multiple users and your database server has enough memory to manage the maximum number of connections that will be in the pool at any given time. In most connection pooling models, it is easy to calculate the maximum number of connections that will be in a pool because the connection pool implementation allows you to configure the maximum.

If the implementation you are using does not support configuring the maximum number of connections in a pool, you must calculate how many connections will be in the pool during peak times to determine if your database server can handle the load. Determine whether the number of database licenses you have accommodates a connection pool. If you have limited licenses, answer the following questions to determine if you have enough licenses to support a connection pool: a.

Will other applications use database licenses If yes, take this into account when calculating how many licenses you need for your connection pool. b. Are you using a database that uses a streaming protocol, such as Sybase, Microsoft SQL Server, or MySQL If yes, you may be using more database connections than you think.

In streaming protocol databases, only one request can be processed at a time over a single connection; the other requests on the same connection must wait for the preceding request to complete before a subsequent request can be processed. Therefore, some database driver implementations duplicate connections (establish another connection) when multiple requests are sent over a single connection so that all requests can be processed in a timely manner. When you develop your application to use connection pooling, open connections just before the application needs them.

Opening them earlier than.
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