April 15, 2008 – Persistent Storage Solutions

Introduction

Oracle Application server 10g is a middle ware software by Oracle. Purpose of Application server is to handle the business intelligent and logic. Below is the difference between a two-tier architecture and multi-tier architecture.

In case of a two-tier architecture we business logic and presentation is both handled by client. Hence we call it thick client. Where as in case of multi tier architecture we have only presentation layer in client side and business logic is handled by Application server. Hence such clients are called as think client. Below is the three tier architecture show.

Advantages of 3-tier architecure

1) In case of change in business logic the change needs to be done only in Application server (mid tier) as its centralized. Where as in case of two tier architecture ever client needs to be changed. So management is easy.

2) It reduces the network traffic, because in case of 2 tier architecture the protocol used is TCP/IP which is a stateful connection (continuous). So even if data is been send or not connection will always be there. This increases network traffic and reduces bandwidth. Where as in 3 tier architecture we have TCP/IP connection only between mid tier and database and is set when client request for some data. As soon as data is provided the connection is closed. The connection between client and mid tier is http which is a stateless connection.

3) Performance is another factor which make 3 tier architecture a better solution over 2 tier architecture. Since all business logic gets executed at client side, performance on client reduces. This is in addition to database performance issue. In case of 3 tier architecture performance is not an issue and is handled well in Application server.

Lets start with Application server 10g

Application Server 10g Components

Below is a very simple line sketch of application server 10g component architecture. This shows what are the components that are present in AS (Application Server) and why those are required.

All the above components shown above comes with AS 10g R2 installation. All these components are categorized as given below.

All the components shown in green color + OHS for mid tier (on left) + Web cache is installed as mid tier components. So mid tier includes

Web Cache
OHS (Oracle HTTP Server)
OC4J
FORMS
REPORTS
DISCOVERER
PORTAL
WIRELESS

While installing this middle tier, the installation of these components are divided into 3 main components.

J2EE and Web Cache (This will install Web Cache, OHS and OC4J)
Portal and Wireless (This will install all components of J2EE and Web Cache + Portal and Wireless components)
Business Intelligence and Forms (This will install all components)

If we are installing just option 1 (J2EE and Web Cache) then infrastructure tier is not required. However we can still install infrastructure tier but in this case it wont be used by these 3 components of mid tier.

If we are installing either option 2 or 3, we have to install infrastructure tier before installing these mid tier components. This is because these middle tier component such as portal and wireless will create there own repository in infrastructure’s meta data repository. So its important that we first install infrastructure tier before installing mid tier, in case we want to go for option 2 or 3 for mid tier.

The other components shown in blue + OHS on right side are installed as infrastructure tier. So infrastructure tier includes following components

OHS (Oracle HTTP Server)
Meta Data Repository
SSO (Single Sign on)
OID (Oracle Internet Directory)
DAS (Delegate Administrative Services)
OCA (Oracle Certification Authority)

Out of the above components of infrastructure tier SSO, OID, DAS and OCA are together called as IDM (Identity Management). So infrastructure tier contains mainly meta data repository and identity management.

Having this brief knowledge above AS 10g R2 components, lets start with installation.

Installing Oracle Application server 10g R2

Before starting the installation, we should complete the pre-installation checks. This includes following steps.

Pre-Installation Task

1) Check the required packages are installed in OS or not.

glibc-2.3.4-2.9
glibc-common-2.3.4-2.9
binutils-2.15.92.0.2-13
compat-libstdc++-296-2.96-132.7.2
gcc-3.4.3-22.1
gcc-c++-3.4.3-22.1
libstdc++-3.4.3-22.1
libstdc++-devel-3.4.3-22.1
openmotif21-2.1.30-11.RHEL4.4
pdksh-5.2.14-30
setarch-1.6-1
make-3.80-5
gnome-libs-1.4.1.2.90-44.1
sysstat-5.0.5-1
compat-db-4.1.25-9
control-center-2.8.0-12
xscreensaver-4.18-5.rhel4.2

you can check the status of package using rpm -q command. as a root user.

2) Add following in /etc/sysctl.conf

kernel.shmall = 2097152
kernel.shmmax = 2147483648
kernel.shmmni = 4096
# semaphores: semmsl, semmns, semopm, semmni
kernel.sem = 256 32000 100 142
fs.file-max = 131072
net.ipv4.ip_local_port_range = 10000 65000
kernel.msgmni = 2878
kernel.msgmax = 8192
kernel.msgmnb = 65535

3) Make entry of hostname and domain name in /etc/sysctl.conf
kernel.hostname=advait
kernel.domainname=oracle.com

4) Make following changes in /etc/security/limits.conf
*        soft   nproc         2047
*        hard   nproc         16384
*        soft   nofile        2048
*        hard   nofile        65536

5) Add the following line to the /etc/pam.d/login file
session required /lib/security/pam_limits.so

6) Make the following entry in /etc/profile
if [ $USER = “oracle” ]; then
if [ $SHELL = “/bin/ksh” ]; then
ulimit -p 16384
ulimit -n 65536
else
ulimit -u 16384 -n 65536
fi
fi

7) Create a group and user.
Primary Group – oinstall
/usr/sbin/groupadd oinstall
Secondary Group
/usr/sbin/groupadd dba
/usr/sbin/useradd -g oinstall -G dba -md /home/oracle oracle
Give the password
[root@dhcp-hydcampusp1-10-176-107-101 home]# passwd oracle
Changing password for user oracle.
New UNIX password:
BAD PASSWORD: it is based on a dictionary word
Retype new UNIX password:
passwd: all authentication tokens updated successfully.

8) Make changes in /etc/hosts as root user and make following entry.

(IP Address) (hostname.domain.name) (hostname)

Example

10.176.106.101 advait.oracle.com advait

Installing Infrastructure Tier

The installation of AS10g should be done in specific order only as explained before. This is because of the dependencies between the components. Here we are going to install Portal and Wireless option of mid tier, this needs database repository for storing the information of these components. So we will first install infrastructure tier and then install Mid tier. Please follow the below screen shots.

run the runInstaller executable present in your Disk1 directory of software dump.

Screen 1 : Welcome – This is the welcome screen. Click on Next.

Screen 2: Specify Inventory location – In this case you can take the default inventory location and then it will ask to run orainstRoot.sh script as root user. Once you run this script as root user on that host, click on continue.

Click on Next

Screen 3: Specify File Locations – Specify the location of Oracle Home for Infra tier and click next.

Screen 4: Select the product to Install – In this case select “Oracle Infrastructure 10g”. If you choose “Oracle Application Server 10g”, then it will install infra tier first and then automatically start installing mid tier.

Screen 5: Select Installation type – As I said before infra tier consists of mainly IDM (Identity Management) and metadata repository. IDM consists of OID, SSO, DAS and OCA. Meta data repository is a 10g oracle database. We will choose both to install here.

Screen 6: runInstaller will perform the basic check on operating system. If for any of the check it generates warning, you can verify the same using the check box and then click on next.

Screen 7: Pre-Installation Requirement – You should have root privileges as you need to run root.sh after installation. Select the checkbox and click on next.

Screen 8: Select Configuration Option – You can select individual components which we are going to install.

Screen 9: Port Configuration Option – For Port Configuration, select Automatic port selection to keep installation simple. Else you can specify the ports in staticports.ini file and upload the same.

Screen 10: Namespace in Internet Directory – Select the default name space only. If your /etc/hosts name file is correct then the default port will be populated correctly. Else it may get populated as localhosts also. In that case check the entry in /etc/hosts.

Screen 11: OCA Distinguish Name – You can specify only the mandatory fields. This is required for creating digital certificate for SSL configuration.

Screen 12: OCA Key length – This is the key length to be used for encryption. You can select the default 2048 and click on next.

Screen 13: OCA Administrator Password – This is the password for Oracle Certificate Authority admin. Select any password, confirm the same and click on next.

Screen 14: Database Configuration Options – Here we provide the name of the database. You can accept the default orcl or give any new name.

Screen 15: Database Schema Password – Select any password for database schema, confirm the same and click on next.

Screen 16: Instance Name and ias_admin Password – Here we are creating a new instance. Note that this is different then database instance. So for infrastructure tier you can give any name (example infra) and also password you want to use for enterprise manager.

Screen 17: Installation Summary – At the end it will show installation summary. Click on Install.

It will show the installation progress. Remember that it is just copying the files and will do some setup. The actual component configuration will come next.

Installer has now started with component configuration. It will configure each component one by one.

When it comes to Meta Data Repository, it will create a new database using DBCA.

At the end of installation it will show the URLs and ports. The above URL is the URL for EM of Infra. Remember we will have 2 EM (Enterprise Manager), one for infra and one for mid-tier.

With the completion of infra tier, we can now start with installation of mid tier. But note that during installation of mid tier your infrastructure tier should be up and running.

Installing Mid Tier components

run the same runInstaller executable present in your Disk1 directory of software dump which you used during infra tier installation.

Screen 1 : Welcome – This is the welcome screen. Click on Next.

Screen 2: Specify File Locations – Specify the location of Oracle Home for mid tier and click next.

Screen 3: Select Product to install – If you remember for infra tier installation we selected second option, i.e. “Oracle Application Server Infrastructure 10g”. Here we have to install mid-tier, which will be present inside “Oracle Application Server 10g” option. So select “Oracle Application Server 10g” option.

Screen 4: Select Installation Type – Here you can select the required installation type depending on the components you want to install. For this installation we will go for Portal and Wireless.

Screen 5: runInstaller will perform the basic check on operating system. If for any of the check it generates warning, you can verify the same using the check box and then click on next.

Screen 6: Pre-Installation Requirement – You should have root privileges as you need to run root.sh after installation. Select the checkbox and click on next.

Screen 7: Select Configuration Option – You can select individual components which we are going to install.

Screen 8: Port Configuration Option – For Port Configuration, select Automatic port selection to keep installation simple. Else you can specify the ports in staticports.ini file and upload the same.

Screen 9: Register with OID – Here you need to provide the hostname and port number of OID which you have already installed as a part of infra tier. By default the port number is 389. You can also check the port numbers of infra tier by going to ORACLE_HOME/install directory and checking file portlist.ini. Here ORACLE_HOME refers to infra ORACLE_HOME.

Screen 10: OID Login – Here OID superuser login should be given. by default its always orcladmin. You have to give the password for this user. This password will be set for orcladmin. You can give any password.

Screen 11: Select AS10g Meta Data Repository – This will show the name of database that we created as meta data repository as a part of infra installation.

Screen 12: Specify Instance Name – Here you will specify the name of the instance that needs to be created for mid tier and also the admin password for logging into EM (Enterprise Manager).