What Linux distributions are used for banking auth hosts on prod?

Question

linux

UPD: given the widespread concern about the unreality of the tasks I set, I will correct the question:
What Linux distributions are used for banking authorization hosts on the production?
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Good day to all.
I have been working in the field of banking processing support for about 5 years, and it became necessary to adjust the career vector towards the implementation and development of banking processing solutions.
In general, if closer to the point, then I need to more or less master the following (based on requests and vacancies that interest me) (in descending order of priority):
- Oracle SQL;
- PL/SQL;
- Administration of Oracle;
- Unix/Linux;
- Windows Server;
- Java;
- J2EE;
- JavaScript;
- bash scripts;
- C++;
- WITH#;
I'm pretty much a noob in all of these areas, tk. although I am a programmer by education, I forgot everything in 5 years without practice (but I quickly delve into it).
For a practical study of all of the above, I decided to do something from a field familiar to me - banking processing.
To be more precise, I plan to take 3 laptops, and in a highly simplified form, 2 of them will be servers of independent banking processing centers (hereinafter PC1 and PC2), and one will be a payment system server (hereinafter MPS), well, and establish a network exchange between them ( online authorization + file clearing (later)).
Based on what I know, I have developed the following global plan of action:
1) Setting up Windows Server 2012 (for PC1) and Linux (For PC2 and MPS);
Expected skills: Linux + Windows Server.
2) Setting up and filling in the Oracle database on each of the servers;
Expected skills: Administration of Oracle + Oracle SQL + PL/SQL.
3) Setting up network interaction between the database;
Expected skills: (?).
4) Setting up application servers;
Expected skills: Java + J2EE.
5) Creation and configuration of Web interfaces;
Expected skills: JavaScript.
Basically, the questions are:
1) Which assembly of Linux is better to choose so that it is as close as possible to what real banking PCs use on the production (you also need to take into account my noobness in this area, because I have been sitting under Windows all my life and have only used Ubuntu for a couple of months, for educational purposes 5 years ago)?
So far I've been advised by Red Hat and Cent OS (I'm leaning more towards the former).
2) What would you adjust in my "Global Plan"?

Answer 1

I participated in the creation of processing, passed PCI DSS successfully, from my experience I can say that you were correctly advised by RedHat and Centos, since according to the standards there should be a subscription to updates (you will have to separately raise the server for updates and monitor) and support from the supplier, otherwise, the auditor can wrap up at the first stage and have to rebuild the architecture, plus usually all this is running on virtual machines, so add virtualization plus idp and ids (WSO2, CAS, Shibboleth) to your list. Well, yes, I agree, the list does not look real, especially Oracle administration, and it’s not clear why C ++ is here, it’s better to have high-level languages ​​\u200b\u200band good knowledge of the basics of programming (OOP, for example, and so on), and we don’t forget design algorithms.
PS:
instead of centos, you can use debian, or maybe you even need it, it all depends on the "religion" of the network administrator
for JAVA, SPRING is better, for example, at CERN, it is used
to the full in databases, you can use POSTGRES, and for studying, especially pay attention to transactions and about XA (distributed transactions) read

Answer 2

Add encryption and signature generation techniques and work under load (It is desirable that your laptops send requests for processing about once a second).