Databases Reference
In-Depth Information
The following steps show how establishing a connection and using shared server pro‐
cesses differ from using a dedicated server process:
1. The client contacts the Listener over the network.
2. The Listener detects an incoming request and, based on the Oracle Net configura‐
tion, determines that it is for a multithreaded server. Instead of handing the client
off to a dedicated server, the Listener hands the client off to a dispatcher for the
network protocol the client is using.
3. The Listener introduces the client and the dispatcher by letting each know the
other's network address.
4. Once the client and the dispatcher know where to find each other, they communi‐
cate directly. The Listener is no longer required. The client sends each work request
directly to the dispatcher.
5. The dispatcher places the client's request in the request queue in the SGA.
6. The next available shared server process reads the request from the request queue
and does the work.
7. The shared server places the results for the client's request in the response queue
for the dispatcher that originally submitted the request.
8. The dispatcher reads the results from its queue.
9. The dispatcher sends the results to the client.
Figure 3-4
illustrates the steps for using the shared servers. Network traffic appears as
dotted lines.
Figure 3-4. Connecting with the Oracle Net Listener (shared servers)
