Oracle Linux / Linux for Oracle Database / Why?

Today's blog post will be about Oracle Linux, a Linux distribution packaged and freely distributed by Oracle, available partially under the GNU General Public License since late 2006.

We deal with this operating system everyday, as most of the critical databases are running on it.
We work with it while managing Oracle databases on commodity systems, but not only that...
We are also getting touch with Oracle Linux as it is embedded in Oracle's leading Engineered Systems, such as Oracle Database Appliance, Exadata, ZDLRA, BDA and so on.

Besides, nowadays, we see it more often. Especially, in environments where 19C database upgrade projects are done. That is , Oracle Linux becomes the first choice for the Oracle customers, who are planning to upgrade their Oracle databases to 19C version. Remember, Linux 7 is a prereq for those customers. So while upgrading their Linux Operating systems, some customers also make a decision to change their Linux distribution and to continue their way with Oracle Linux.

According to the industry analyst firm IDC, Oracle Linux's market growth is significant:  
 “Oracle Linux has been consistently one of the fastest growing enterprise Linux distributions in the past few years. Much of this growth comes from customers moving to Oracle Linux in order to take advantage of ‘Oracle on Oracle’ i.e., Oracle’s OS optimization for its own solution stacks, running on-premises and in the cloud” - Ashish Nadkarni, IDC 

Today, I want to shed a light on the reasons behind this decision actually.
These reasons that I will summarize below, are also the causes that make Oracle itself use Oracle Linux in its own systems and leading engineered systems.

Oracle's own database, middleware, and application software engineering projects is running on Oracle Linux.. Each day, Oracle Linux receives more than hunderds of hours of database and applications tests. So in a way, if we are using Oracle products then we are safer on Oracle Linux.

Having Oracle databases or applications running on Oracle Linux means an end to end Oracle stack. This provides administration and support efficiency. (single vendor support, no need for cross-platform skill sets etc..)

Oracle Engineering is putting lots of efforts including stress tests, performance tests and system verification on Oracle Linux in order to certify the Oracle Applications with it. Again we are safer.

In Oracle Linux, we have the opportunity to use Oracle's own kernek UEK , which is optimized for the best performance. Yes! This UEK kernel has performance enhancements.. It has optimized system calls and C library interfaces. UEK delivers these enhancements and optimizations to the process scheduler, memory management, file systems, and the networking stack.
This means you have an advantage in performance (in applications performance and in query processing times), as well as in transaction capacity and scalability.

When both application stack (including the database layer) and OS stack is from the same vendor, there is an opportunity to have a big integration between these layers.. When you add the industry collobrations to this, you get a significant advantage. Oracle Linux distinguishes itself from the other OS platforms with these abilities (ofcourse in addition to the UEK )

Oracle Linux engineers are  focused on Linux development. They improve their abilities by dealing with this operating system in a very big installed base. They have things developed and those things are now parts of the Linux kernel. Such as RDS, which was developed by Oracle in order to have low-latency connectionless protocol , which improves database performance in Linux. Oracle Engineers also tuned the infiniband stack. At the same time, the collobration between Intel and Oracle made it possible to accelerate columnar compression/decompression+encyrption operation and improve the Numa scalability.
This means, Oracle Linux is a distribution, which is developed in a tightly integrated environment and it is developed with the Oracle Products in the primary focus. This is an advantage if we are using Oracle Products , especially the Oracle database.

So far so good. As we are specifying the reasons that makes customers to choose Oracle Linux, we also must list the features of Oracle Linux. Because these features are also important factors for customers making this decision.

Resource management, ability to perform instance caging by binding instances to specific Cpus.
Ability to pin the processes to the same processor and  same memory nodes on Numa architecture.. (this numa binding increases performance, as the relevant the cpus used by the relevant processes access local memory - rather than non-local memory..)

Ability to use a smart flash cache, by expanding the database buffer cache to a second-level flash drive based cache. (flash access is much more faster than disk access). This is directly related with the database customers. In order to expand the buffer cache, what we need to do is ->just attach the flash drive and make our database use it by setting the relevant database parameters and restarting the database;
SQL>  alter system set db_flash_cache_file='/dev/sdb' scope=spfile;
System altered.
SQL> alter system set db_flash_cache_size=1G scope=spfile;
System altered

By using the ksplice, we can have Zero downtime updates for the kernel and key user space libraries with no reboots or interruption. This simplfies the maintanence and increases the continuity+availability for our mission critical database applications.

With the MCE(Machine Check Exception) daemon running on Oracle Linux, we can trigger events based on the certain error thresholds in Cpu or memory. This daemon can also take actions based on the thresholds. So, we have a tool that presents information like hardware errors , parity and cache errors to OS..

With the integrity check mechanism (following T10 PI -- Protection Information), we have an opportunity to perform integrity checks from the application to OS, through the switch and host bus adapter, and to the disk storage device itself.
Oracle has an open source interface to be used for this task.
Read the following whitepaper for getting more info on this ->
http://www.oracle.com/us/technologies/linux/prevent-silent-data-corruption-1852761.pdf

Oracle Real Application Clusters, which provides redundancy in the event of a hardware or software failure, is free of charge for Oracle Linux Basic and Premier Support customers. This is definitely a good reason..

Oracle Linux has built-in security mechanisms like ip filtering for firewall capabilities, strong encryption, and military-grade SELinux mechanisms. In addition to this OS level security mechanisms, Oracle Linux is tested and recommended for hosting Oracle Database Security options. (TDE, Data Redaction, Audit Vault and Database Firewall)

Virtualization, Cloud Readiness and Managebility are 3 other important reasons for using Oracle Linux. We have OVM, KVM and ready-to-use, easy-to-deploy VM templates for having fully configured oracle software environments and OS images in virtual machines. Today, even EBS or CRM application can be directly provisioned using these templates. In the cloud side, we get Oracle Linux support at no additional cost directly when we subscribe to OCI. With this support, we can use ksplice, 24/7 Linux support services , MOS Linux knowledge base and Oracle Enterprise Manager (for linux management). By the use of enterprise manager for linux management, we reduce infrastructure management cost + TCO.

Oracle's enterprise engineered systems are running Oracle Linux. This is one of the most important reasons for choosing Oracle Linux actually.

Engineered systems running Oracle Linux:

• Exadata
• ODA
• Exalytics
• BDA
• Private Cloud Appliance
• ZDLRA

Finally, we have validate configurations, which can be used as references for having easier, faster, and lower-cost deployments of Oracle Linux and Oracle VM solutions..
These validated configuration are published in oracle technetwork;
https://www.oracle.com/technetwork/topics/linux/validated-configurations-085828.html

Oracle Linux is free to download. All errata is freely available from Oracle Linux Yum server.

Oracle supplies preinstall packages (like preinstall rpms) for Oracle Database, even for EBS. Morever, Oracle Linux provides packages for developers, scripting languages and database connectors via Yum.

Well.. I tried to list the reasons that makes Oracle Linux to be choosen and these reasons make the Oracle Database run best on Oracle Linux actually..

There may be more reasons to list, and things to discuss of course , but it is obvious that you can deploy your Oracle databases or Oracle Application to Oracle Linux with peace of mind. 

So let's download a copy of Oracle Linux and get started :)
See you on my next blog post, which will be a short and clean one -- about Oracle Linux licensing  :)
I almost forgot, here is my tech review Oracle Linux. (I did it on 2017 actually, so it is an old one, but still.. have a look..)

https://www.itcentralstation.com/product_reviews/oracle-linux-review-42176-by-it_user600741