4 ms·

Cobol programmers are starting to get few nowadays, and finding people that actually want to be trained in it is not that easy. Plus you dont just need programm

by fork1 9y ago

Cobol programmers are starting to get few nowadays, and finding people that actually want to be trained in it is not that easy. Plus you dont just need programmers, but z/OS engineers, DB2 DBAs, MQ specialists, etc. And that's before you even start talking about the nice cheque you're writing for IBM every month. It does add up.

pjmlp 9y ago
It is still cheaper than porting to the language du jour, like changing plane engines in mid-flight, while ensuring that the new system meets 100% of the existing requirements.
- fork1 9y ago
  There are alternatives, but i'm biased. See my other comment. One of the biggest hurdle we have is that the clients dont usually have many tests in place. Testing and validating a full batch night for example (ie 6 hours of intense batch work) is quite complicated.
  - pjmlp 9y ago
    I see, it is a valid alternative. What do you think about the .NET and JVM Cobol compilers? They seem to be a way to move that code into new systems with no rewrites as well.
    - fork1 9y ago
      Well, i know of at least one client that still has the binaries but not the sources of the cobol. But for the generic case, the mainframe is quite an integrated system, and big clients tend to use a lot of the features at the same time. Even if you can produce an executable or a library, but you ll still need a transaction manager (CICS/IMS-TM), a database (DB2/IMS), MQ, RACF, Datasets, GDG, REXX/JCL, etc. You need the whole ecosystem. And all the binaries will expect a DB2, or a MQ listening on the other side, with near-perfect emulation (return codes, db behaviour such as EBCDIC sorting, etc). Just compiling wont help you much unless you have a very basic use of mostly JCL and batches.
yourapostasy 9y ago
Most if not all such managers (I always look for explanations in these cases that are not ascribed to an abstract business entity, but to individual people) have no stomach for porting. A typical manager's tenure over an organization that might have the scope to perform the port is shorter than the porting project itself. No manager wants to have such a large, expensive, risky project on their accomplishments list as "started, but not finished", especially if a successor gets to claim all the credit later if it does finish successfully: that successor then becomes direct competition on the corporate ladder climb. Also, I've yet to see such businesses opt for the safest porting approach. Build a transaction replication system, then a component of the ported system. Inbound transactions are replicated and dispatched to the legacy and the component of the ported system simultaneously. Build scaffolding to monitor key transaction metrics. Compare output and performance results. Let that "bake" for a year or two. Rinse and repeat with the next component (many such ported components can be developed in parallel, etc.), and so on, until the ported system reaches feature parity with the legacy system, then let the completed version "burn in" for 2-3 of the longest periodic process lifecycles. For example, if the the longest periodic process the application supports is once every 7 years, then you burn in for up to 21 years, comparing during the entire duration. By the time you "throw the switch" to the ported system, you have a very high certainty that it will work just as well if not better than the legacy system. Extremely low-risk, but extremely expensive, and considered extremely impractical. And with how business-critical some of these systems are, pretty much any risk mitigation short of this will get nixed by senior management. This doesn't even begin to get into other factors, like changing regulatory and business environment as you are porting (so you're porting and modifying for new requirements simultaneously), such a project can easily be targeted for the cutting block for just the cost savings to make someone in Finance look good, internal political issues, developer churn over such a long period, developers on the legacy system withholding key implementation or even business requirements information, that information simply not being available, binary-only parts of legacy, etc.
- fork1 9y ago
  As i've made clear in my other posts in this thread, i dont believe in rewrites. I've seen lots of very painful ones though, and never quite finished, nor iso-functional. However, there are other ways to unplug the mainframe. I would disagree with the assessment that management is too dysfunctional, it depends. But if they all were like you described, i would be out of work. And it just happens that we turned off a mainframe just 2 weeks ago.

by fork1 9y ago

pjmlp 9y ago

It is still cheaper than porting to the language du jour, like changing plane engines in mid-flight, while ensuring that the new system meets 100% of the existing requirements.

fork1 9y ago
There are alternatives, but i'm biased. See my other comment. One of the biggest hurdle we have is that the clients dont usually have many tests in place. Testing and validating a full batch night for example (ie 6 hours of intense batch work) is quite complicated.
- pjmlp 9y ago
  I see, it is a valid alternative. What do you think about the .NET and JVM Cobol compilers? They seem to be a way to move that code into new systems with no rewrites as well.
  - fork1 9y ago
    Well, i know of at least one client that still has the binaries but not the sources of the cobol. But for the generic case, the mainframe is quite an integrated system, and big clients tend to use a lot of the features at the same time. Even if you can produce an executable or a library, but you ll still need a transaction manager (CICS/IMS-TM), a database (DB2/IMS), MQ, RACF, Datasets, GDG, REXX/JCL, etc. You need the whole ecosystem. And all the binaries will expect a DB2, or a MQ listening on the other side, with near-perfect emulation (return codes, db behaviour such as EBCDIC sorting, etc). Just compiling wont help you much unless you have a very basic use of mostly JCL and batches.

yourapostasy 9y ago

Most if not all such managers (I always look for explanations in these cases that are not ascribed to an abstract business entity, but to individual people) have no stomach for porting. A typical manager's tenure over an organization that might have the scope to perform the port is shorter than the porting project itself. No manager wants to have such a large, expensive, risky project on their accomplishments list as "started, but not finished", especially if a successor gets to claim all the credit later if it does finish successfully: that successor then becomes direct competition on the corporate ladder climb. Also, I've yet to see such businesses opt for the safest porting approach. Build a transaction replication system, then a component of the ported system. Inbound transactions are replicated and dispatched to the legacy and the component of the ported system simultaneously. Build scaffolding to monitor key transaction metrics. Compare output and performance results. Let that "bake" for a year or two. Rinse and repeat with the next component (many such ported components can be developed in parallel, etc.), and so on, until the ported system reaches feature parity with the legacy system, then let the completed version "burn in" for 2-3 of the longest periodic process lifecycles. For example, if the the longest periodic process the application supports is once every 7 years, then you burn in for up to 21 years, comparing during the entire duration. By the time you "throw the switch" to the ported system, you have a very high certainty that it will work just as well if not better than the legacy system. Extremely low-risk, but extremely expensive, and considered extremely impractical. And with how business-critical some of these systems are, pretty much any risk mitigation short of this will get nixed by senior management. This doesn't even begin to get into other factors, like changing regulatory and business environment as you are porting (so you're porting and modifying for new requirements simultaneously), such a project can easily be targeted for the cutting block for just the cost savings to make someone in Finance look good, internal political issues, developer churn over such a long period, developers on the legacy system withholding key implementation or even business requirements information, that information simply not being available, binary-only parts of legacy, etc.

fork1 9y ago
As i've made clear in my other posts in this thread, i dont believe in rewrites. I've seen lots of very painful ones though, and never quite finished, nor iso-functional. However, there are other ways to unplug the mainframe. I would disagree with the assessment that management is too dysfunctional, it depends. But if they all were like you described, i would be out of work. And it just happens that we turned off a mainframe just 2 weeks ago.