Kbase 20756: Possible Cause for Indefinite ODBC Connections-MDAC Pooling
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
10/16/2008 |
|
Status: Unverified
FACT(s) (Environment):
Active Server Pages
SYMPTOM(s):
Problem using Active Server Pages (ASP) served either by IIS or other ODBC applications.
Connections are sometimes staying in place even though the calling application closes all the connections.
IIS
ODBC
CAUSE:
Microsoft MDAC pooling is one possible cause for this behavior.
FIX:
Both ODBC and OLE Database support the pooling of database connections. Pooling enables an application to use a connection from a pool of connections that do not need to be reestablished. When connections are placed in a pool, an application can reuse that connection without
performing the complete connection process.
For either ODBC or OLE Database, pooling creates and maintains a group of connections to a database or other data storage device and hands them out to consumers that request a connection to that data store.
Because applications open connections to a given data store and subsequently release them, a pool of open connections is built with complete authentication information and connection properties. If available, connection requests to the same data store (with the same user authentication and connection properties) are satisfied from the pool rather than by making the connection on demand.
Connections are held open for a period of time after a consumer application has released them. They are released by the pooling mechanism when they time out.
Pooling is available in two forms for applications that use the Microsoft Data Access Components:
- ODBC offers connection pooling through the ODBC Data Source
Administrator.
- OLE Database core components provide resource pooling as well as
additional services such as shaping and the client-side cursor.
Please refer to Progress Solutions 20757 and 20758 for more information on ODBC connection pooling