> # Planning Connection Models

> The type of connection model you choose for your SequeLink configuration partly depends on your SequeLink Server platform, the scalability requirements, and whether you are using the distributed transaction functionality of a DBMS. SequeLink provides the following types of connection models:

> - The ThreadPool connection model starts SequeLink with a preallocated minimum number of threads that can be increased when needed to a specified maximum number of threads. These threads can be shared by multiple SequeLink Clients connected to the SequeLink Server. This connection model provides optimum scalability-many client connections can be serviced with the same system resources on the server. It is the default connection model for all platforms. (ServiceConnectionModel=ThreadPool)

> See "Connection Model Default Behavior" for information about the SequeLink service attributes that define the size of the thread-pool engine and that govern how the thread-pool engine works.

> - The Process/Connection connection model creates a separate operating system process for each SequeLink Client connection request. This connection model is not valid on z/OS. (ServiceConnectionModel=Process/Connection)
> - The Thread/Connection connection model provides a dedicated thread for each SequeLink Client connection to a SequeLink Server. Use the Thread/Connection connection model for client applications that are database-intensive, such as bulk load or bulk transfer applications. (ServiceConnectionModel=Thread/Connection)