Re:Saving Data: Reducing the Size of App Updates by 65%
by chousuke on Wednesday December 07, 2016 @01:28PM
(#13124852)
If you use systemd you can assign services to slices which can be assigned cgroup resource reservations / limits. I don't think any distro does too much with this out of the box yet (IIRC by default all services run under a single "system" slice, and user sessions under a user slice), but it should be possible to run an "emergency environment" slice in which the processes are always guaranteed some small amount of resources necessary to recover.
Re:Saving Data: Reducing the Size of App Updates by 65%
by JdeBP on Thursday December 08, 2016 @10:04AM
(#13130680)
The LinkedIn people report that it's not that simple.
* https://engineering.linkedin.com/blog/2016/08/don_t-let-linu...
Speaking of: is there a good way to ask an OS to "reserve memory and CPU-time" for emergency interactive maintenance (e.g. spawning a console on a thrashing box), in a similar way to how ext2/3/4 "reserves space" for the root user for emergency maintenance?
The only real way I can think of to do this (that doesn't involve already knowing what processes could thrash and cgroup'ing them) is to run a hypervisor and treat the dom0 as the emergency console. That still doesn't let you get inside the thrashing instance to fix it, though.