The
clients don??™t interact directly with the database server. Some examples of calling services
provided by a TP monitor on a remote machine seem similar in many ways to
the stored procedure architecture described in the previous section, which is why
stored procedure-based systems are sometimes referred to as ???TP-Lite.???
Application servers provide additional valuable services, such as:
Funneling
Like Oracle??™s shared servers, application servers leverage a pool of shared services
across a larger user population. Instead of each user connecting directly to
the database, the client calls a service running under the TP monitor or application
server??™s control. The application servers invoke one of its services; the
service interacts with the database.
Connection pooling
The application server maintains a pool of shared, persistent database connections
used to interact with the database on behalf of clients in handling their
requests. This technique avoids the overhead of individual sessions for each
client.
Load-balancing
Client requests are balanced across the multiple shared servers executing on one
or more physical machines.
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