On 18 March 2016 at 20:58, Benjamin Mahler <bmah...@apache.org> wrote: > Interesting, why does it take down the slaves?
This was a good while back, but when swap gets low our slaves kernel OOM killer tended to mess things up. > Because a lot of organizations run with swap disabled (e.g. for more > deterministic performance), we originally did not set the swap limit at all. > When we introduced the '--cgroups_limit_swap' flag we had to make it default > to false initially in case any users were depending on the original behavior > of no swap limit. Now that it's been available for some time, we can > consider moving the default to true. This is actually reflected in the TODO > alongside the flag: > > https://github.com/apache/mesos/blob/0.28.0/src/slave/flags.cpp#L331-L336 > > Want to send a patch? We'd need to communicate this change to the default > behavior in the CHANGELOG and specify how users can keep the original > behaviour. I'll see if I can get time - just about to finish a consulting gig and was going to take a break, so it might be an option. Thanks for the explanation, I *knew* there'd be a reason :) > Also, there's more we would need to do in the long term for use cases that > desire swapping. The only support today is (1) no memory limits (2) memory > limit and no swap limit (3) both memory and swap limits. You can imagine > scenarios where users may want to control how much they're allowed to swap, > or maybe we want to swap for non-latency sensitive containers. However, it's > more complicated (the user and operator have to co-operate more, there are > more ways to run things, etc), and so the general advice is to disable swap > to keep things simple and deterministic. > > On Fri, Mar 18, 2016 at 11:34 AM, Dick Davies <d...@hellooperator.net> > wrote: >> >> Great! >> >> I'm not really sure why mesos even allows RSS limiting without VMEM, >> it takes down slaves like the Black Death >> if you accidentally deploy a 'leaker'. I'm sure there's a use case I'm >> not seeing :) >> >> On 18 March 2016 at 16:27, Shiyao Ma <i...@introo.me> wrote: >> > Thanks. The limit_swap works. > >
