IBM introduces z15 mainframe

Re:IBM introduces z15 mainframe by jeremyjh on Sunday September 15, 2019 @08:37AM (#20976952)

I'd guess they are only used to run legacy mainframe software. The accounting systems (loan accounting, deposits, etc) of large banks for example are all based on very old COBOL code bases and have lots of assumptions about their OS platform built into them. These code bases are not only very stable and well-tested but they are deeply integrated into hundreds of other systems in the bank. Porting them from Z/OS or replacing them is probably out of the question, but there more are modern tools for integrating them into a services-oriented architecture for example.

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Re:IBM introduces z15 mainframe by coleca on Sunday September 15, 2019 @10:00AM (#20977228)

Surprisingly there are reasons why running financial type systems in COBOL makes a lot of sense. Evidently COBOL really excels at foxed point decimal operations more so than other “modern” languages like Python and Java. Porting then off the mainframe isn’t a trivial exercise it seems.

https://medium.com/@bellmar/is-cobol-holding-you-hostage-wit...

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Re:IBM introduces z15 mainframe by jeremyjh on Sunday September 15, 2019 @10:58AM (#20977467)

Java has had a fixed point type - BigDecimal - for a couple of decades now. Yes, there are people who don’t know what they are doing using floats for currency.

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Re:IBM introduces z15 mainframe by Retric on Sunday September 15, 2019 @11:38AM (#20977697)

It’s far more than just having a single data type.

COBOL was in effect designed for business use so fixed point arithmetic has a lot of support in the language, libraries, and tooling.

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Re:IBM introduces z15 mainframe by rbanffy on Sunday September 15, 2019 @04:50PM (#20979423)

One useful way of thinking of COBOL is as a DSL targeted at business operations.

Once you do that, it becomes clear Java is not exactly a competitor.

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Re:IBM introduces z15 mainframe by coldtea on Sunday September 15, 2019 @11:55AM (#20977780)

>Java has had a fixed point type - BigDecimal - for a couple of decades now.

Which is neither here nor there. COBOL has end to end support for financial/commercial calculations, and a whole lot more.

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Re:IBM introduces z15 mainframe by jeremyjh on Sunday September 15, 2019 @12:53PM (#20978139)

If you clicked the link from the person I was responding to, and read that article, you would know why my comment is relevant.

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Re:IBM introduces z15 mainframe by coldtea on Sunday September 15, 2019 @01:00PM (#20978171)

I've read that article a couple of weeks before. It still doesn't posit a simplistic "Java has bigdecimal, just ditch COBOL" as the solution. From the article:

"When you are a major financial institution processing millions of transactions per second requiring decimal precision, it could actually be cheaper to train engineers in COBOL than pay extra in resources and performance to migrate to a more popular language. After all, popularity shifts over time."

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Re:IBM introduces z15 mainframe by jeremyjh on Sunday September 15, 2019 @01:10PM (#20978226)

The entire premise of that article was based on the example of "engineers" trying to port COBOL code to Java and using floats for maths of financial transactions. Yes, they can't say "just use BigDecimal" and still have enough content to be ranked well by Google, but that in fact is the solution to that particular problem.

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Re:IBM introduces z15 mainframe by mamcx on Sunday September 15, 2019 @12:01PM (#20977806)

That is like to say in Java you can have nullable types.

But because is not in-built any advantage of use it get lost in the noise.

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Re:IBM introduces z15 mainframe by neverartful on Sunday September 15, 2019 @11:27AM (#20977633)

This is true. The mainframe has hardware support for fixed point instructions (I don't know the details). IIRC, the POWER line (p and i) also have hardware support.

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Re:IBM introduces z15 mainframe by AnimalMuppet on Sunday September 15, 2019 @09:45PM (#20980517)

> COBOL really excels at foxed point decimal operations

That's one of the best typos I've ever seen.

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