Overview of Oracle Application Server
Oracle Tips by Burleson Consulting
Being complex, an Oracle Application Server
environment has a huge amount of tuning opportunities. For
example, the Oracle database back-end has more than 250 initialization
parameters, each Oracle Application Server component has many
interrelated parameter and configuration settings, and each server has
dozens of tuning options. Tuning any one of the Oracle Application
Server components is challenging by itself, but when we consider the
complex interactions between Oracle Application Server components, there
can be an overwhelming amount of tuning activity.
We must start by noting that every Oracle
Application Server system has a bottleneck. Even a well-tuned
Oracle Application Server system will have some resource that comprises
the majority of the response time. The best approach is to
identify the component that is the bottleneck and then drill-down and
identify the component resource that is responsible for the latency.
The bottleneck may be hardware related (CPU, RAM, Disk I/O, or Network
shortages), or software related (locks, latches or contention).
There are two approaches to Oracle Application
Server tuning, the reactive and proactive approach. In the
reactive approach, we receive a response time complaint from the
end-user community and we use tools such as OEM to ascertain the cause
of the performance problem. In the proactive tuning approach we
collect detailed statistics from all Oracle Application Server
components, analyze the data, and develop predictive models that can
predict those conditions that will impede performance.
Let?s start by examining the tuning ?knobs?.
By altering a knob, we adjust the configuration and resources for the
Oracle Application Server farm and change the processing
characteristics. Common knobs or Oracle Application Server include
three areas, server tuning, parameter tuning and RAM cache tuning:
Hardware configuration ?
Adding RAM of CPU resources to existing servers will improve the
throughput on the server
Hardware load balancing ? The
addition of new servers to the Oracle Application Server farm and
relocating Oracle Application Server components onto the servers allows
for scalability during times of peak usage. Spare servers can be
configured with both Web Cache and App Server, and the appropriate
components can be started as-needed.
Server parameter tuning ?
Adjusting the parameters on your server can have a huge impact on the
performance of the Oracle Application Server components running on that
Oracle Application Server
parameters - Adjusting the Oracle Application Server configuration
parameters for each Oracle Application Server component has influence
performance and throughput.
Database parameters ? Because
most Oracle Application Server systems are disk I/O intensive, adjusting
the Oracle database parameters for the Infrastructure database (iasdb)
and the back-end database can heavily influence performance.
RAM cache tuning
Data buffer tuning ? Adding
RAM to the database db_cache_size on the Oracle Infrastructure and
back-end database can greatly reduce disk I/O and improve throughput.
Web cache tuning ? Adding RAM
to the Oracle Application Server web cache can improve the delivery
rates of HTML and XML though the Oracle HTTP Server (OHS).
As we mentioned, proactive
tuning is the best approach for the tuning of Oracle Application Server
because we can analyze historical database and observe trends and
identify performance thresholds. In order to do proactive
monitoring we must develop data collection mechanisms for the servers
and each Oracle Application Server component.