Modify Kernel Parameters Oracle Application Server Tips by Burleson Consulting

The next step is to modify the kernel parameters.  Oracle Application Server 10g is highly multithreaded and in Linux all threads are spawned as processes.  As a result, the kernel must be configured to handle a large number of processes.  If you are only going to install the J2EE and Web Cache the default kernel parameters will work, otherwise you will need to make the modifications below.  Since the kernel will need to maintain the configuration after rebooting they need to be implemented in the /etc/sysctl.conf file.  Open the sysctl.conf file in your favorite editor and add the following lines.

#Oracle 9ias params
kernel.sem = 256 32000 100 142
kernel.shmmax = 4294967295
kernel.shmmni = 4096
kernel.shmall = 2097152
kernel.msgmax = 8192
kernel.msgmni = 2878
kernel.msgmnb = 65535
net.ipv4.ip_local_port_range = 1024 65000
fs.file-max = 131072

The above configuration is the minimum except for:

Shmmax  = 2147483648
Shmmni  = 142

If your current parameters are greater than those specified, use the current setting.  Save the file and reboot the server to use the new settings.  You can verify that the new parameters are being used after rebooting by listing then with the below command:

[root@appsvr root]# /sbin/sysctl ?a

The next step is to increase the shell limits.  Edit the /etc/security/limits.conf file adding the following lines at the end.

*               soft    nofile          2048
*               hard    nofile          16384
*               soft    nproc           2047
*               hard    nproc           16384

Each line follows the format:

*<Tab><Tab>soft<Tab>nofile<Tab><Tab>2048

Save the file.  Next edit the /etc/pam.d/limits.conf file adding the following line at the bottom if it does not exist.

session    required     /lib/security/pam_limits.so

Next, verify that the port 1521 is not being used.

[root@appsvr root]# netstat -an | grep 1521

Verify that the port is not being used, as it is required for the Metadata Repository database.  This port can be shared with another Oracle database but if it is being used by any other application you must change the port the other application uses.

Create the Oracle User and Groups

Like Oracle databases, the oracle operating system user usually installs the application server.  The easiest way to create the oracle user and the install groups is from the command line as the root user.  First create the install group to own all the product files.

[root@appsvr root]# groupadd oinstall

If you are installing the infrastructure instance you will need the database groups to manage the metadata repository database.

[root@appsvr root]# groupadd dba
[root@appsvr root]# groupadd oper

Next create the oracle user and assign the oinstall as the primary group.

[root@appsvr root]# useradd ?g oinstall oracle

If you are installing the infrastructure, the oracle user needs to be assigned to the dba and oper groups also.

[root@appsvr root]# useradd ?g oinstall ?G dba,oper oracle

Now set the oracle users password.

[root@appsvr root]# passwd oracle

You will be asked for a password and then asked to verify the password.  Before you change to the oracle user, you need to set some environmental variables.  As root edit the /etc/profile file adding the following code to increase the file number limit and process number limit for the oracle user.

if [ $USER = "oracle" ]; then
   if [ $SHELL = ?/bin/ksh? ]; then
      ulimit -n 16384
      ulimit ?p 16384
   else
      ulimit ?u 16384 ?n 16384
   fi
fi

Place the code before the export statement.  At the end of the file before the ?unset i? statement define the TMP directory.  You can also define a TMPDIR directory but if you don?t the installer will just use the TMP directory.

TMP=/tmp; export TMP
TMPDIR=/tmp; export TMPDIR

Log out and log in as the oracle user.  You can verify that the limits are set correctly with the below command.

[root@appsvr root]# su ? oracle
[oracle@appsvr oracle]$ ulimit ?aH
core file size (blocks)     unlimited
data seg size (kbytes)      unlimited
file size (blocks)          unlimited
max locked memory (kbytes)  unlimited
max memory size (kbytes)    unlimited
open files                  16384
pipe size (512 bytes)       8
stack size (kbytes)         unlimited
cpu time (seconds)          unlimited
max user processes          16384
virtual memory (kbytes)     unlimited

Note:  You must be the oracle user when you execute the command because the limits are set only for the oracle user.

Downloading the Software

You can get the Oracle Application Server 10g software from otn.oracle.com.  Download the four files to the stage directory (whichever you choose as long as it is owned by the oracle user).  The four files are archived using a utility called cpio and then compressed using gzip.  To extract the files, first unzip all four files using the gunzip utility.

[oracle@appsvr oracle]$ gunzip ias904_linux_disk1.cpio.gz

Next use the cpio utility to extract the files from the archive.  The cpio utility will create the files in the subdirectories from which they were archived so after using cpio on the four files you will be left with four subdirectories, Disk1 through Disk4.

cpio ?idmv < ias904_linux_disk1.cpio

Notice that you pipe the file into the cpio utility.

In the example below, I extracted the files in the /home/oracle/ias directory.

[oracle@appsvr ias]$ ls ?l
drwxr-xr-x    7 oracle   oinstall     4096 Dec 15 18:21 Disk1
drwxr-xr-x    3 oracle   oinstall     4096 Dec 15 11:59 Disk2
drwxr-xr-x    3 oracle   oinstall     4096 Dec 15 12:00 Disk3
drwxr-xr-x    3 oracle   oinstall     4096 Dec 15 12:01 Disk4

You will find the installer in the Disk1 subdirectory.

Optional But Recommended Configuration

The next two changes are optional but recommended and were required in previous releases of Oracle?s application server.  The /etc/hosts file is used to resolve host names to IP addresses to included the local loopback.  The installer should use the hosts file in its installed format however it is recommended that you place it in the following format.

127.0.0.1       localhost.proxitec      localhost
192.168.1.49    appsvr.proxitec.com     appsvr

If you are not using a static IP address, you must add the local loopback address for the hostname so that the different application server components can resolve the host IP.

127.0.0.1       localhost.proxitec      localhost
127.0.0.1       appsvr.proxitec.com     appsvr

Finally it is recommended that you remove the Linux LDAP service and free the port for Oracle?s LDAP implementation called Oracle Internet Directory.  If you do not execute this step, the installer will assign a free port to OID without a problem.  By executing this step, the installer can configure OID to use the standard LDAP ports.  Unless you have applications using the Linux LDAP that you do not want to integrate in to OID, you should execute this step.  You need to edit the /etc/services file removing all line containing the port numbers 386 and 636.  You should remove four lines, two for each port.  Save the file and reboot the server.

 

This is an excerpt from "Oracle 10g Application Server Administration Handbook" by Don Burleson and John Garmany.