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> OOP isn't good or bad, Exceptions aren't good or bad, Scrum isn't good or bad. It makes me mad. It's all true though. Do whatever you want, all that matters

> OOP isn't good or bad, Exceptions aren't good or bad, Scrum isn't good or bad. It makes me mad. It's all true though. Do whatever you want, all that matters is that you do it well - you just can't simplify a good software engineer down to techniques like these. I recommend reading this piece from a guy who studied software development methodology for over 20 years: http://alistair.cockburn.us/Characterizing+people+as+non-linear,+first-order+components+in+software+development/v/slim http://alistair.cockburn.us/Characterizing+people+as+non-lin...

jstimpfle 9y ago
No. There are very objective reasons why e.g. exceptions do not work for projects of advanced complexity. In short, they add additional, hard to see code paths and a redundant method of result handling (with its own noisy syntax, and new semantics) that brings grand-scheme structural complexity (now EVERY component must be exception-safe, every added feature's behaviour with respect to exceptions must be validated) that affects the whole project. Once you realize it starts to be a problem you cannot fix it anymore because it affects the whole project. This is why bigger projects use less and less features. Using only few features might slow development a little in the small, and you might even make more errors in the small while developping. But you can FIX them. I realize this is not hard science, and I have no motivation to do any on it, like collecting and bending statistics. But as long as all people have to say "XY is not good or bad", "things will get better", "XY has just a very steep learning curve", "you just didn't dance the right dance" and all evidence seems to suggest otherwise, then you've just lost the argument. End of story.
- barrkel 9y ago
  Exceptions work excellently for business-level server software; typically they make the server transaction all or nothing, with transactional semantics. The stateless nature of HTTP, and transactions provided by the database, usually add up to make this easy. Business logic throws an exception, everything unwinds, the transaction rolls back, no state was modified, and the server returns an error code to the client: all good. When you need partial updates to state in the case of an error, then you're in trouble. When you have multiple transactions to coordinate, but no distributed transaction coordinator, you're in trouble (but you are anyway whether you use exceptions or not). The more state you need to preserve in an error case, the worse exceptions are for your use case. Ideally, exceptions are never caught except at the topmost loop: server request dispatcher, UI event handler, or command line driver. When execution must continue with recovery, exceptions are an inferior tool.
  - jstimpfle 9y ago
    A http request handler is not what I mean by server software. I mean a real server - a long-running process with complex state. Yes, exceptions work for simple programs and short scripts (where you don't handle them at all), or as a plug-in mechanism where there is a catch-all handler at the boundary. I kind-of value exceptions as well for writing python scripts.
    - barrkel 9y ago
      To a first approximation, most servers with distinct codebases are HTTP app servers ("request handlers"). And not just simple programs and short scripts; very complex programs, as long as they keep state in a transactional store, and a request has approximately the same lifetime as the transaction.
      - jstimpfle 9y ago
        Sure, if you want to think of the thing that is formed by all combined requests from all clients over the lifetime of the database, as a program - then that might (or might not) be a complex program. But the unit in which exceptions are confined with this architecture is the simple, dirty request handler script. Which likely doesn't even try to handle any errors, and may actually be a bad, faulty program - the edge cases just don't matter that much for businesses. Maybe an e-mail will be sent out twice in a few circumstances, etc: nobody cares. Transaction management is implemented in the database server, and very likely that doesn't employ exceptions. And more complexity is implemented by the OS (the "process server" if you will) - if your program dies it specifies how to handle the condition, etc. Another part of complexity is dealt with by the language runtime, for example garbage collection - no exceptions to be seen there.
        brianpgordon 9y ago
        > Sure, if you want to think of the thing that is formed by all combined requests from all clients over the lifetime of the database, as a program The thing that serves responses to requests is a program. And it's not just a "simple, dirty request handler script," it's often enormously complex. Entire companies exist with their product exposed via HTTP APIs. The reason you don't see exceptions in databases, operating systems, etc is because they're often written in C++, which has notoriously wonky semantics around exceptions, or C, which doesn't have exceptions at all.
spookthesunset 9y ago
The thing is, what is the alternative to a scrum process? I see so many shops with zero defined process constantly re-invent project management wheels that were solved a long time ago. Start from a known place like scrum and then adapt it to your team and organization. We standardize around protocols, frameworks, programming languages, etc because adding constraints and processes make a problem much easier to solve. If not scrum, what? Where do you start?
- user5994461 9y ago
  Kanban, gantt, unified process, extreme programming, trello, rfc. There are plenty of methodologies and tools that can replace or complement Scrum.
  - SAI_Peregrinus 9y ago
    Or even the engineering design process. Every ABET accredited engineering program teaches it, and while there are minor variations in the specifics it's always broadly the same. It's worked well in the engineering disciplines for decades & produces reliable products. There's no reason it can't work well for software, only an unfortunate case of "not invented here syndrome".
gregdoesit 9y ago
A fascinating read, thank you for sharing. These gems of knowledge are what I love HN for. >This paper outlines the work I reviewed that made it clear to me that ‘people’ really are a first-order, and not incidental, project success driver, the characteristics I currently use as predictors. My personal experience is similar - methodologies can make things incrementally better for a team, but cannot do anything with the ‘people’ factor.
baq 9y ago
this is a fantastic piece you've linked, i'm impressed how well it holds up after 20 years, and it admits on multiple occasions that it's been all known 30 years before it's been written. amazing.

jstimpfle 9y ago

No. There are very objective reasons why e.g. exceptions do not work for projects of advanced complexity. In short, they add additional, hard to see code paths and a redundant method of result handling (with its own noisy syntax, and new semantics) that brings grand-scheme structural complexity (now EVERY component must be exception-safe, every added feature's behaviour with respect to exceptions must be validated) that affects the whole project. Once you realize it starts to be a problem you cannot fix it anymore because it affects the whole project. This is why bigger projects use less and less features. Using only few features might slow development a little in the small, and you might even make more errors in the small while developping. But you can FIX them. I realize this is not hard science, and I have no motivation to do any on it, like collecting and bending statistics. But as long as all people have to say "XY is not good or bad", "things will get better", "XY has just a very steep learning curve", "you just didn't dance the right dance" and all evidence seems to suggest otherwise, then you've just lost the argument. End of story.

barrkel 9y ago
Exceptions work excellently for business-level server software; typically they make the server transaction all or nothing, with transactional semantics. The stateless nature of HTTP, and transactions provided by the database, usually add up to make this easy. Business logic throws an exception, everything unwinds, the transaction rolls back, no state was modified, and the server returns an error code to the client: all good. When you need partial updates to state in the case of an error, then you're in trouble. When you have multiple transactions to coordinate, but no distributed transaction coordinator, you're in trouble (but you are anyway whether you use exceptions or not). The more state you need to preserve in an error case, the worse exceptions are for your use case. Ideally, exceptions are never caught except at the topmost loop: server request dispatcher, UI event handler, or command line driver. When execution must continue with recovery, exceptions are an inferior tool.
- jstimpfle 9y ago
  A http request handler is not what I mean by server software. I mean a real server - a long-running process with complex state. Yes, exceptions work for simple programs and short scripts (where you don't handle them at all), or as a plug-in mechanism where there is a catch-all handler at the boundary. I kind-of value exceptions as well for writing python scripts.
  - barrkel 9y ago
    To a first approximation, most servers with distinct codebases are HTTP app servers ("request handlers"). And not just simple programs and short scripts; very complex programs, as long as they keep state in a transactional store, and a request has approximately the same lifetime as the transaction.
    - jstimpfle 9y ago
      Sure, if you want to think of the thing that is formed by all combined requests from all clients over the lifetime of the database, as a program - then that might (or might not) be a complex program. But the unit in which exceptions are confined with this architecture is the simple, dirty request handler script. Which likely doesn't even try to handle any errors, and may actually be a bad, faulty program - the edge cases just don't matter that much for businesses. Maybe an e-mail will be sent out twice in a few circumstances, etc: nobody cares. Transaction management is implemented in the database server, and very likely that doesn't employ exceptions. And more complexity is implemented by the OS (the "process server" if you will) - if your program dies it specifies how to handle the condition, etc. Another part of complexity is dealt with by the language runtime, for example garbage collection - no exceptions to be seen there.
      - brianpgordon 9y ago
        > Sure, if you want to think of the thing that is formed by all combined requests from all clients over the lifetime of the database, as a program The thing that serves responses to requests is a program. And it's not just a "simple, dirty request handler script," it's often enormously complex. Entire companies exist with their product exposed via HTTP APIs. The reason you don't see exceptions in databases, operating systems, etc is because they're often written in C++, which has notoriously wonky semantics around exceptions, or C, which doesn't have exceptions at all.

spookthesunset 9y ago

The thing is, what is the alternative to a scrum process? I see so many shops with zero defined process constantly re-invent project management wheels that were solved a long time ago. Start from a known place like scrum and then adapt it to your team and organization. We standardize around protocols, frameworks, programming languages, etc because adding constraints and processes make a problem much easier to solve. If not scrum, what? Where do you start?

user5994461 9y ago
Kanban, gantt, unified process, extreme programming, trello, rfc. There are plenty of methodologies and tools that can replace or complement Scrum.
- SAI_Peregrinus 9y ago
  Or even the engineering design process. Every ABET accredited engineering program teaches it, and while there are minor variations in the specifics it's always broadly the same. It's worked well in the engineering disciplines for decades & produces reliable products. There's no reason it can't work well for software, only an unfortunate case of "not invented here syndrome".

gregdoesit 9y ago

A fascinating read, thank you for sharing. These gems of knowledge are what I love HN for. >This paper outlines the work I reviewed that made it clear to me that ‘people’ really are a first-order, and not incidental, project success driver, the characteristics I currently use as predictors. My personal experience is similar - methodologies can make things incrementally better for a team, but cannot do anything with the ‘people’ factor.

baq 9y ago

this is a fantastic piece you've linked, i'm impressed how well it holds up after 20 years, and it admits on multiple occasions that it's been all known 30 years before it's been written. amazing.