NonStop Server Guide for BEA WebLogic Server 9.2

Introduction
HP NonStop Server Guide for BEA WebLogic Server 9.2—529891-002
1-4
Native Socket Multiplexer
.
Another aspect of the Java socket multiplexer implementation that impacts the overall
performance of the WebLogic Server application is the kernel execute queue. The
kernel execute queue is configured with threads that perform server internal functions
and application request processing. When the pure Java socket multiplexer is used,
the number of socket readers is expressed as a percentage of the kernel default
execute queue. As a result, the number of threads that can service other requests is
reduced.
To overcome this, a native socket multiplexer facility has been included in the
WebLogic Server product. This native socket multiplexer eliminates the need to poll the
sockets by providing a set of dedicated poller threads. These threads call the native
code implemented in C and C++ to use the host operating system-specific facility to
wait for I/O events on the sockets.
As shown in Figure 1-2, a single thread N1, waits for I/O events on all the active
sockets S1 through S6. When an I/O event is triggered in any of the sockets, the
operating system notifies the thread about the event. The thread wakes up to service
the I/O event on the socket. This greatly reduces the unnecessary overhead in polling
the sockets and reduces the processor resource utilization by the WebLogic Server.
Figure 1-1. Socket Reader Polling
SP1 SP6SP2 SP3
SP4
SP5
SR1 SR2 SR3
VST003.vsd