> When I claim it's a feature, but describe the pain it is to use, I get told nearly nobody uses it. When I claim that nobody uses it, I get told that lots of people use it.
Heh it is funny. I might have an idea why. It is hard to use regularly to perform day to day releases. Simply because building correct apups and so on take a lot of time. Most systems are already decomposed into separate nodes and cand handle single node maintenance, so that is what we do at least. Take a node down, upgrade, bring it back up. Care has to to taken to have mixed version in a cluster but that is easier than proper 100% clean hot upgrade.
But having said that, I have used hotpatching by hand probably 5-6 times in the last couple of months. Once on a 12 node live cluster. That was to fix an one-off bug, for that customer before having to wait for a full release, another time was to catch an function_clause error that was crashing gen_server and so on. It was is very valuable having that ability.
> till, at this point, if someone's going to claim that Erlang could go C speed or even close to it in the general case, I'm very firmly in the "show me and I'll believe it" camp.
It doesn't matter if it goes C speed, it has the fault tolerance, expressive language, it is battle tested, it has good runtime inspection and monitoring capability, if someone came one day and said you lose all those but you gain C speed, I wouldn't make that trade.
Heh it is funny. I might have an idea why. It is hard to use regularly to perform day to day releases. Simply because building correct apups and so on take a lot of time. Most systems are already decomposed into separate nodes and cand handle single node maintenance, so that is what we do at least. Take a node down, upgrade, bring it back up. Care has to to taken to have mixed version in a cluster but that is easier than proper 100% clean hot upgrade.
But having said that, I have used hotpatching by hand probably 5-6 times in the last couple of months. Once on a 12 node live cluster. That was to fix an one-off bug, for that customer before having to wait for a full release, another time was to catch an function_clause error that was crashing gen_server and so on. It was is very valuable having that ability.
> till, at this point, if someone's going to claim that Erlang could go C speed or even close to it in the general case, I'm very firmly in the "show me and I'll believe it" camp.
It doesn't matter if it goes C speed, it has the fault tolerance, expressive language, it is battle tested, it has good runtime inspection and monitoring capability, if someone came one day and said you lose all those but you gain C speed, I wouldn't make that trade.