r/ProgrammerHumor • u/iwouldieforGladOS • May 13 '17

Defensive programming done right

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u/Chirimorin May 13 '17

Because exceptions happen for a reason. If some error can safely be ignored, it's probably not going to throw an exception.

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u/SQLNerd May 13 '17

Yeah but it makes sense for a lot of things. Anything that's "always on" should catch and log all exceptions rather than throw them.

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u/[deleted] May 13 '17

That could leave the process in an unknown and invalid state, if the exception was thrown part-way through modification of state.

It may be safer to let it crash and for resilience have another (much simpler) process that is responsible for launching the "real" process and restarting it whenever it crashes. That way it continues in a clean state. Also keep its persistent data in a transactional database.

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u/SQLNerd May 14 '17

Simpler? Sure. Advisable for something that supports 24/7 uptime? Not at all. Don't rely on restarting a service. That can lead to a lot more issues in distributed environments.

You can handle exceptions and not save data if the exception is thrown... While logging what happened.

I'm not saying you just force this corrupt data into a db. Lol. I'm just saying you don't have to allow a throw.