r12 d49656 gc10-apps dba 08

Copyright © 2007, Oracle. All rights reserved.

Advanced Configuration Options

Copyright © 2007, Oracle. All rights reserved.1 - 2

Objectives

At the end of this module, you should be ableto do the following:• Describe use of a shared application tier file system in

Oracle Applications• Explain the benefits of using a staged APPL_TOP• Identify the main load balancing options and their key

features• List the major factors in efficient network design for Oracle

Applications


Module Overview

This module discusses the following topics:• Shared Application Tier File System• Load Balancing Options• Network Features


Shared Application Tier File System - Introduction

A shared application tier file system is a single Application tier file system that can be accessed simultaneously from more than one machine:• The application tier file system disk is attached to a mount

point of the same name on all machines


Shared Application Tier File System – Not In Use

Without a shared application tier file system, each application tier node has its own file system, which must be managed independently:


Shared Application Tier File System – In Use

With a shared application tier file system, all application tier nodes share a single file system, which simplifies maintenance:


Shared Application Tier File System – Features

A shared application tier file system can be used for all nodes in an application tier:• In Release 12, all application tier file systems contain the

same installed files• An application tier can be shared immediately

– It is not necessary to start from scratch• Specific sharing technologies are not certified

– The shared file system must simply be accessible from all nodes

• The Release 12 Rapid Install can install a shared application tier file system


Shared Application Tier File System – Benefits

Using a shared application tier file system has several benefits:• Machines can easily be added to an existing system in order

to: – Maximize system availability– Cater for additional usage requirements

• Disk space requirements are greatly reduced.• Administrative tasks need only be carried out

once, on any node


Shared Application Tier File System - Availability

Using a shared application tier file system offers several advantages in the area of high availability: • An Applications patch only needs to be applied once,

minimizing downtime• It is easier to add nodes, to cater for more users and provide

greater resilience


Load Balancing – Introduction

The various Applications technology layers can be distributed across a larger or smaller number of machines, according to:• Physical topology• Required performance• Desired expenditure

Other possible factors include:• Growth in user base• Fluctuations in demand• Resilience in the event of hardware problems


Load Balancing – Strategic Effect

Load balancing involves the entire infrastructure of an Oracle Applications installation:• Performance can often be improved using existing hardware• A change in one area can potentially have effects elsewhere


Load Balancing – Areas

Principal load balancing areas include:• Domain Name Server• HTTP Server• Concurrent Processing Layer• Database Layer


Load Balancing – Session Persistence

The two main categories of load balancer are:• Session Persistent Load Balancers, which always direct

HTTP requests from a client to the same server– Client connections are session-persistent– This is also referred to as stickiness

• Non-Session Persistent Load Balancers, which do not necessarily direct HTTP client requests to the same server

– Client connections are not session-persistent


Load Balancing – SSL Accelerators

Another type of load balancer uses Secure Sockets Layer (SSL) Accelerators, which:• Reduces the SSL traffic and workload of the Web server• Converts SSL HTTPS client browser requests to non-SSL

HTTP requests• Directs subsequent request to the HTTP server

A reverse of this process is used to send the response back to the browser

SSLAccelerator

HTTPS

HTTPS HTTP

HTTP

Web Server


Load Balancing – Specific Options

Several different types of load balancing can beemployed with Oracle Applications:• They range from the relatively simple to the more

sophisticated• The load balancing solution should integrate with the existing

infrastructure of a site


Load Balancing – DNS Layer

DNS Layer LoadBalancing distributesrequests based ondynamic assignmentsof IP addresses to afully qualified domainname:


Load Balancing – HTTP Layer

HTTP Layer LoadBalancing requires ahardware load balancerthat accepts HTTPcommunication andforwards it to a group(farm) of server nodes:


Load Balancing – Concurrent Processing Layer

Parallel Concurrent Processing (PCP) enables you to:• Run concurrent processes on multiple nodes to improve

concurrent processing throughput• Continue running concurrent processes on the remaining

nodes when one or more nodes fail• Administer concurrent managers running on multiple nodes

from any node in the clusterPCP is enabled by default, so is always available for use


Load Balancing – Database Layer

Oracle Real Application Clusters (Oracle RAC) harnesses the processing power of multiple computers:• All active instances can concurrently execute transactions

against a shared database• Oracle RAC coordinates each instance's access to the

shared data, to provide data consistency and integrity• All E-Business Suite modules can be successfully deployed

against an Oracle RAC-enabled database


Network Features – Introduction

When deploying a global IT infrastructure, the choice of network topology can be critical. There are a number of significant strategic factors:• Basic structure• Latency• Satellite Links• Wireless LANs

Each of these will be discussed briefly on the following slides


Network Features – Strategies

A large organization will typically use a hub and spoke network topology:• High-capacity links serve regional hubs, with medium-

capacity connections to local offices• The routes and hops need to be as short and efficient as

practicable

High-capacity linkMedium-capacity link

Regional hubLocal office

Example Network Topology


Network Features – Latency

Latency is the time for a packet to travel from its source to its destination, and can be significant:• Oracle Applications works well with average latencies up to

300ms– Performance is generally acceptable with latencies up to

500ms• Where latency is marginal, forms may be slower to load (for

example, on startup)– In such circumstances, HTML-based applications may give

better performance than Forms-based applications


Network Features – Satellite Links

Satellite links can be used as a network link for Oracle Applications:• They are considered to be just another network type• They may be the only choice for users in remote locations• They should only be employed where use of terrestrial

services is not feasible• The network stack may need to be tuned

The goal is to achieve reliable operation, while maintaining an acceptable response time


Network Features – Wireless LANs

As well as security aspects, deployment of wireless technology must take into account technical considerations, including:• Overall stability of the connection• Momentary loss of service may occur as a result of:

– Not having the latest firmware revision– Interference from devices using a similar wavelength, such as

cordless phones• Use of Forms Listener Servlet (the default in Release 12),

with its capability to attempt reconnection


Network Features – Wireless LANs

Wireless LANs are simply considered as another network topology, so are not explicitly supported (or unsupported) with Oracle Applications• A problem should if possible be reproduced using a non-

wireless link• If it cannot be reproduced, the wireless link will need to be

checked


Module Summary

In this module, you should have learned howto do the following:• Describe the advantages of using a shared application tier

file system• Identify the main load balancing options and their key

features• List the major factors in efficient network design for Oracle

Applications


Module Discussion

• Summarize the features offered by a shared application tier file system

• List three possible benefits of load balancing• Describe the effect of latency on a network, and how it

affects Oracle Applications• Why does use of the Forms Listener Servlet often help with

network operation?

r12 d49656 gc10-apps dba 08

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