Configuring the Operating System

4 Configuring the Operating System

This chapter describes how to configure operating systems supported by Oracle Communications ASAP.

About Configuring the Operating System

ASAP can be installed on Oracle Linux. This section describes procedure relating to configuring operating system and other required applications for use with the ASAP server software.

Before proceeding, the appropriate version of the UNIX operating system must be installed on any machines that will be running ASAP server software, and the machines must be configured to be part of your network. See ASAP Compatibility Matrix for a list of supported operating systems.

Note:

In order to install and configure the UNIX environment for ASAP as described in this section, you must be familiar with the UNIX operating system. You should know how to configure users and groups, understand shells, and be able to manipulate file and directory permissions. You also need to understand a number of other UNIX system administration concepts.

Configuring a UNIX ASAP Group and User

To support installation and running of ASAP, each ASAP environment that you create must have at least one dedicated UNIX ASAP group and one dedicated ASAP user account within that group. You may choose to have additional ASAP users in the ASAP group, depending on your specific implementation.

Prior to installing ASAP, you must create a UNIX ASAP group and an ASAP user. The ASAP group must be the primary group of the ASAP user.

Creating the UNIX ASAP Group

This group is required to coordinate access to files that are needed to develop and test ASAP. All UNIX users of ASAP must belong to this group.

Note:

Oracle recommends that you use UNIX groups to coordinate the read/write access required for ASAP. You can use any other name for the group that is appropriate for the project, as long as the ASAP and environment users belong to that group.

Create a group for ASAP with the following members:

ASAP user account
root

Creating the UNIX ASAP User Account

Each ASAP environment must have a dedicated UNIX user account. For development purposes, you may have multiple ASAP environments. In this case, you must define multiple users. In a production environment, you generally have only one environment and therefore only one group and user.

Oracle recommends for configuration if you set the home directory of the ASAP user to be the same directory where you plan to install the ASAP software. Take this into account when you set up the home directory.

Create the ASAP user and password, and make the user's primary group the newly created ASAP group. Additional ASAP user accounts may be needed depending on your implementation.

Note:

You must use this ASAP user account to create the directory where ASAP will be installed. The installer uses the ASAP user account to access the UNIX system and must have write privileges on the destination install directory.

Checking /tmp and /var/tmp Directory Status

You must ensure that the directories /tmp and /var/tmp have their permissions set so that they are writable by all ASAP users. To do this:

Check the permissions on the /tmp directory:
```
cd /
ls -l | grep tmp
```
Check that the permissions string has the appropriate settings for the ASAP group. Use chmod to update the permissions if needed. For example:
```
chmod a+rwx tmp
```
Check the permissions on the /var/tmp directory.
```
cd /var
ls -l | grep tmp
```

Configuring the Kernel

There are certain UNIX kernel configuration parameters that require tuning so that both the database and ASAP function correctly. The most important aspect of UNIX kernel configuration is to provide an environment in which the database server can handle hundreds of concurrent connections.

The following are the principal areas that require tuning:

Shared memory

Oracle Database requires the ability to share large amounts of memory. Typically, the potential shared memory size should be 100 MB or greater.
Open files per process

The RDBMS server is expected to manage a large number of concurrent connections. These connections constitute open file descriptors to the RDBMS Server. The maximum number of file descriptors dictates the maximum number of concurrent connections that can be managed by the RDBMS Server. To support multiple ASAP environments, the UNIX kernel should be configured to support an appropriately large number of open files per process.

Note:

Consult with your operating system administrator to determine a value.

In addition, some operating systems use the concept of soft and hard file limits. Ensure that both limits are set appropriately.

To update the UNIX kernel configuration:

Using the information below and in "Configuring the Kernel" update the UNIX kernel parameters.
Reboot the machine after you have made the changes.

For more information, see the ASAP System Administrator's Guide.

Note:

When ASAP is deployed on the same platform as the Oracle Database or WebLogic Server instance, use the highest kernel value recommended in either ASAP, Oracle Database, or WebLogic Server documentation.

Setting Linux Kernel Parameters

Oracle recommends that the kernel parameters shown in Table 4-1 are set to values greater than or equal to the value shown.

The procedure following the table describes how to verify and set the values manually.

Note:

The kernel parameter and shell limit values shown in the following section are recommended values, and should be modified after installing Oracle 19c Client for Linux and before installing ASAP.

Table 4-1 lists and describes the recommended kernel parameter settings for supported Linux systems.

Table 4-1 Kernel Parameter Configuration

Parameter	Recommended Value	File and Description
`semmsl` `semmns` `semopm` `semmni`	250 3200 32 128	/proc/sys/kernel/sem This file contains the four numbers that define the limits of the System V IPC semaphores. These fields are: `semmsl`: The maximum number of semaphores per semaphore set. `semmns`: The system-wide limit on the number of semaphores in all semaphore sets. `semopm`: The maximum number of operations that may be specified in a semop(2) call. `semmni`: The system-wide limit on the maximum number of semaphore identifiers.
`shmall`	268435456	/proc/sys/kernel/shmall This file contains the system-wide limits on the total number of pages of System V IPC shared memory.
`shmmax`	4294967295	/proc/sys/kernel/shmmax This file can be used to query and set the run-time limit on the maximum System V IPC shared memory segment size that can be created. Oracle recommends 4 GB for optimum system performance.
`msgmax`	65536	/proc/sys/kernel/msgmax The `msgmax` tunable specifies the maximum allowable size of any single message in a System V IPC message queue, in bytes. msgmax must be no larger than msgmnb (the size of the queue).
`msgmnb`	65536	/proc/sys/kernel/msgmnb The `msgmnb` tunable specifies the maximum allowable total combined size of all messages queued in a single System V IPC message queue at one time, in bytes. The default is 16384.
`msgmni`	2878	/proc/sys/kernel/msgmni The `msgmni` tunable specifies the maximum number of system-wide System IPC message queue identifiers (one per queue). The default is 16.
`threads_max`	131072	/proc/sys/kernel/threads-max Gets and sets the limit on the maximum number of running threads system-wide.
`file-max`	327679	/proc/sys/fs/file-max This file defines a system-wide limit on the number of open files for all processes.
`queues_max`	256	/proc/sys/fs/mqueue The `queues_max` is a read/write file for setting and getting the maximum number of message queues allowed on the system.
`msgsize_max`	8192	/proc/sys/fs/mqueue The `msgsize_max` is a read/write file for setting and getting the maximum message size value. This message queue attribute is used when creating any message.
`msg_max`	32767	/proc/sys/fs/mqueue The `msg_max` is a read/write file for setting and getting the maximum number of messages in queue value.

Table 4-2 provides the commands to display the current values of the kernel parameters. Make a note of these values and identify any values that you must change.

Table 4-2 Commands to Display Kernel Parameters

Parameter	Command
`semms1`, `semmns`, `semopm`, and `semmni`	`# /sbin/sysctl -a \| grep sem` Displays the value of the semaphore parameters in the order listed.
`shmall`, `shmmax`, and `shmmni`	`# /sbin/sysctl -a \| grep shm` Displays the details of the shared memory segment sizes.
`msgmnb`, `msgmni`, and `msgmax`	`# /sbin/sysctl -a \| grep msgm` Displays the details of the System V IPC message queue parameters.
`threads-max`	`# /sbin/sysctl -a \| grep threads-max` Displays the maximum number of threads possible system-wide.
`file-max`	`# /sbin/sysctl -a \| grep file-max` Displays the maximum number of open files throughout the system.
`queues_max`	# /sbin/sysctl -a \| grep queues_max Displays the maximum number of message queues allowed on the system.
`msgsize_max`	`# /sbin/sysctl -a \| grep msgsize_max` Displays the maximum message size value.
`msg_max`	`# /sbin/sysctl -a \| grep msg_max` Displays the maximum number of messages in a queue value.

If the value of any kernel parameter is different from the recommended value, perform the following:

Using any text editor, create or edit the /etc/sysctl.conf file, and add or edit lines similar to the following:

Note:

Include lines for kernel parameters values that you want to change. For the semaphore (kernel.sem) parameter, you must specify all values. However, if any of the current values are larger than the recommended values, then specify the larger value.
```
kernel.sem = 250 32000 32 128
kernel.shmall = 268435456
kernel.shmmax = 4294967295
kernel.msgmax = 65536
kernel.msgmnb = 65536
kernel.msgmni = 2878
kernel.threads-max = 131072 
fs.file-max = 327679
fs.mqueue.queues_max = 256
fs.mqueue.msgsize_max = 256
fs.mqueue.msg_max = 32767
```
By specifying the values in the /etc/sysctl.conf file, these values persist when you restart the system.
Enter the following command to change the current values of the kernel parameters:
```
# /sbin/sysctl -p
```
Review the output from the command to verify that the values are correct. If the values are incorrect, edit the /etc/sysctl.conf file, then enter this command again.
Enter the command /sbin/sysctl -a to confirm the values are set correctly.
After updating the values of the kernel parameters in the /etc/sysctl.conf file, either restart the computer, or run the command sysctl -p to make the changes in the /etc/sysctl.conf file available in the active kernel memory.

Required Linux Packages for ASAP on Linux 8

You must install the following Linux 64-bit packages before you install database client, WebLogic server, and ASAP. The ASAP installer fails to start if there are any missing packages.

The required Linux packages are:

bc
binutils
elfutils-libelf
fontconfig
glibc
glibc-devel
csh
ksh
libaio
libasan
liblsan
libX11
libXau
libXi
libXrender
libXtst
libgcc
libibverbs
libnsl
librdmacm
libstdc++
libxcb
libvirt-libs
make
policycoreutils
policycoreutils-python-utils
smartmontools
sysstat