What are some of the advantages and disadvantages of using cobol on a mainframe?

It is important to keep in mind that COBOL's problem space is business applications. You don't write a regex engine in COBOL. You don't implement the Quicksort algorithm in COBOL. You probably could, but that's not its problem space so just don't. If you're a government or a credit card company or an insurance company or a financial institution doing OLTP and you need serious speed, reliability, recoverability, and securability then COBOL and CICS and DB2 or IMS on a mainframe are your happy place.

COBOL is known for its simplicity, using English words and phrases for ease of understanding. It was designed with business applications in mind, excelling in file handling and data processing. Its universality allows it to function across various platforms, offering robust debugging and testing tools. COBOL is also recognized for its reliability and security. On the modern front, COBOL has embraced object-oriented programming since 2002, facilitating contemporary coding methodologies. It can integrate with current languages like Java and SQL for hybrid system solutions. Modern COBOL IDEs provide syntax highlighting, error checking, and debugging tools to support codebase maintenance.

Mainframes are known for their high availability and reliability. COBOL applications on mainframes have a proven track record of stability and robustness. Mainframes offer significant processing power, allowing COBOL programs to efficiently handle large volumes of data and complex calculations. z/OS is a highly secure platforms, providing built-in security features and safeguards to protect sensitive data, making them suitable for handling critical and confidential information.Mainframes can easily scale up to handle increasing workloads, accommodating the growth of COBOL applications without significant performance degradation.

In fact . Mainframe & Cobol give more stable compared to AWS / AZure. Infact Mainframe systems highly secure & data integrity.

Mainframes, such as IBM z16, are some of the world's most reliable platforms with 99.999999% reliability, which is up by one nine from the previous generation of systems. This doesn't happen by accident. It takes a lot of innovation and engineering to add an additional nine to the end of that string. In practice, mainframes have reduced the downtime of from three seconds per year, down to less than half a second per year. This is why companies use theses systems to run their most mission critical workloads, because they can rely on these systems to be able to handle the demand.

While reliability, IO and security are among the top selling points for mainframes they're also more environmentally friendly than decentralized platforms. In an age where every industry must do their part to save the planet, mainframes are the greatest asset to the modern datacenter.

As per IBM, "The level of reliability and redundancy introduced in mainframes is in the range of 99.999% (the five 9's)". Availability is the degree to which a system is ready when needed to process data, is key in providing around the clock services.

Think colossal power & rock-solid reliability? Think mainframes! They may not fit in your pocket, but these data-crunching beasts handle massive transactions (think millions/day, banks & airlines!) with blazing speed, ironclad security, and always-on availability. Unfazed by surges, they scale seamlessly and upgrade smoothly, ensuring critical apps never hiccups. Despite the whispers, mainframes remain relevant, offering unmatched performance for businesses needing ultimate stability.

Mainframes are renowned for their exceptional processing power and scalability, capable of handling vast data volumes and executing billions of transactions swiftly, making them suitable for large organizations. They are designed for high reliability, with the latest IBM z16 mainframe offering 99.9999999% uptime, ensuring continuous availability for critical applications. Mainframes also provide robust security features, making them ideal for applications requiring high data security levels. They possess large memory and data processors, enabling them to manage massive databases and files. Furthermore, mainframes can handle multiple programs and support numerous users simultaneously providing concurrent multi-user access.

While it is true that there is a widespread belief that Cobol experts are on the way to extinction, learning Cobol is not difficult, I have formed groups of 12-15 Cobol developers within a month, month and a half. The complexity of Cobol is not in the language itself, but in the complexity of the applications to which the language is dedicated, and in another order of measurement in the mainframe context necessary for a Cobol developer to be efficient.

The biggest one — IT WORKS! And is easy to learn. Also — it will be here tomorrow (see APL, ADA and other “modern” languages)

Investment protection. Applications written since the beginning of S/360 and the operating at that time, MFT, continue to run today without modification on the latest hardware platform, I/O technology and version of z/OZ operating system. The mainframe infrastructure is continual enhanced to provide value transparently to the applications (e.g. parallel OEMI, ESCON, FICON, etc...).

COBOL has significantly better support in modern mainframe development than other mainframe languages from the same era, there's better support for COBOL in modern VS Code extensions than PL/I.

The language itself is not hard to learn. It is very mature and performant. Over the decades most applications written in it have become a complex ball of mud but I assume this is a problem you'll face in every language. Re-writing such an application is risky and expensive. Continuing with COBOL is the most economical thing companies can do. But the development processes need to be modernized. Young talents are fine with learning COBOL (which is a matter of a few weeks). But they'll run away if you torture them with development processes and tools from the digital stone age. The main problems I see is if departments don't move to git and VSCode/IDz and IBM doesn't include and support standard tools like git in the operating system.

COBOL does best what it is intended for- deal with millions of records in a few seconds. Contrary to popular beliefs, COBOL as a language is not complex at all. The complexity of a Cobol program lies in the business logic integrated within the code. Most good Cobol programmers are also efficient business analysts, and possess a good business knowledge of the industry they are working in. COBOL is a beautiful concoction of technology and business, exactly what it was developed for. In contrary, I have hardly met distributed systems programmers having a significant business knowledge.

From my experience working with COBOL in a mainframe environment, Maintenance Complexity is a concern. COBOL programs on mainframes are often decades old and can be complex, making maintenance challenging. The lack of modularity and the sheer size of legacy codebases can lead to high maintenance costs.

There is a PERCEPTION that COBOL and mainframes are outdated technologies, making it harder to attract younger developers and the risk of dwindling support or resources in the long term as newer languages gain prominence.

COBOL compiles to native code and has neither introspection nor reflection. Therefore, tricky code that retrieves the attributes of an identifier or determines the presence of a paragraph with a particular name at runtime is impossible. Introspection and reflection are controversial in languages that support them, within COBOL's problem space they are most often unnecessary. Dynamic SQL can be accomplished but only with significantly more difficulty than static SQL. Some might see this as a feature. Contrary to the supplied text, COBOL does not require knowledge of the mainframe architecture and in fact abstracts it.

You can't compare Cobol with other modern languages. Still, we used Cobol for batch jobs. Daily and monthly, some jobs run on the mainframe for calculating interest, back pay, automatic money transfer, and so on.

Online Resources: Courses, books, tutorials - dive deep into COBOL syntax, logic, & the mainframe world. Hands-on Practice: IBM Z Open Editor & Open Mainframe Project let you experiment on virtual machines or cloud systems. Community Support: Forums, blogs, and enthusiast groups offer tips, advice, and a network of COBOL champions.

To learn COBOL and mainframe programming, consider engaging with online courses and tutorials available on platforms like Interskill, Udemy, Coursera. Additionally, explore mainframe training resources provided by IBM and other organizations, including IBM's Developer website and the Open Mainframe Project. Hands-on practice is crucial; look for courses that include interactive labs and projects simulating mainframe environments for practical experience in writing and testing COBOL code. Joining online communities, forums, and Slack channels can also be beneficial for connecting with experienced programmers, sharing knowledge, and resolving queries.

I always recommend the book "Beginning COBOL for programmers", it's generally easy to follow along with and it covers most of the information you'll need. The IBM course "Learning COBOL programming with VSCode" is a great place to start when it comes to getting your hands dirty.

To learn Mainframe, consider the below steps: Online Courses and Tutorials: Enroll in online courses on platforms like Coursera, Udemy, or IBM's own training resources that cover mainframe basics, COBOL, JCL, and other relevant languages and tools. Certification Programs: Consider pursuing IBM's professional certifications, such as the IBM Certified System Administrator - z/OS. Books and Documentation: Read comprehensive guides and manuals like "Introduction to the New Mainframe: z/OS Basics" available through IBM's documentation. Hands-On Practice: Utilize mainframe simulators or seek access to actual mainframe systems through academic partnerships, internships, or employers offering mainframe environments for learning and practice.

To secure a job in COBOL and mainframe programming, actively search on portals like Indeed, LinkedIn, using Mainframe specific keywords like "COBOL" and "mainframe developer" to filter opportunities. Enhance your resume and online profiles by showcasing your COBOL and mainframe skills, certifications, and projects. Engage in networking by joining relevant online communities and professional networks on platforms like LinkedIn, which can lead to unadvertised job openings. Consider remote job opportunities, as the demand for remote COBOL and mainframe developers is growing. Lastly, commit to continuous learning to stay ahead of latest COBOL and mainframe technology trends, making you a more competitive candidate in this specialized field.

Best place to start is LinkedIn. For new developers, I would recommend that you start following the industry leaders and their companies, and keep an eye out for job openings posted by mainframe-using companies and consultancies. Every now and then there are offers for beginners and training scholarships in Cobol/Mainframe that surely offer opportunities to get started in this world. Follow the big banks, insurance companies, utilities, consulting companies, LinkedIn alerts by keywords (Mainframe, Cobol, JCL, DB2, CICS, etc). In the meantime, nourish yourself with the free online courses that IBM, BMC, and other companies provide on their websites. In a short time you will have entered a profession that, if you want it, will be for life.

Mr. Kumar. Does DB need freelance and remote working Cobol developers then Im ready for a quick start. I have worked for Commerzbank, FI, IBM and other in Germany. I also speak German. Feel free to contact me here on LinkedIn.

To get a job in Mainframe, use portal like Naukri, Indeed and LinkedIn. Connect with the people on Linkedin who are currently working into Mainframe. Focus on growing your network.

LinkedIn and Indeed are in my opinion is the top place to be found by the recruiters. Make sure your skills in the LinkedIn matches to the Mainframe skillsets that can help you land your next Mainframe job. Also reaching out to your colleagues and having them endorse your Mainframe skills can go a long way, better if you could get them to write a recommendation for the work that have done with them.

COBOL has been the foundational language for many business applications, and the fact that is has stood the test of time should be evidence enough that is it not going away any time soon. Tools like watsonx Code Assistant for IBM Z can help organization lower cost with less risk. This tool can automate code refactoring and aide with COBOL to Java conversion. What ever language a development organization chooses to write their mainframe applications in, using tools like WCA to accelerate code development and increase production are going to be an essential part of your development team’s tool kit.

COBOL for mainframe development provides reliability in mature programming environments crucial for legacy systems. Its English-like syntax enhances readability for intricate operations. Robust support for business applications aligns seamlessly with mainframe strengths. Challenges persist. COBOL's verbosity may slow development, and its syntax can seem outdated. Finding skilled COBOL programmers is increasingly difficult, impacting maintenance. Integrating COBOL with contemporary technologies poses challenges. In conclusion, COBOL is robust for mainframe applications, balancing strengths with challenges. Organizations must assess factors like development efficiency, talent availability, and long-term sustainability.