On Sat, Jan 4, 2020 at 4:48 AM drago01 <drago01@xxxxxxxxx> wrote: > > > > On Saturday, January 4, 2020, Neal Gompa <ngompa13@xxxxxxxxx> wrote: >> >> On Sat, Jan 4, 2020 at 2:33 AM Vitaly Zaitsev via devel >> <devel@xxxxxxxxxxxxxxxxxxxxxxx> wrote: >> > >> > On 03.01.2020 22:27, Neal Gompa wrote: >> > > and servers... >> > >> > Admins will be very happy when such user-space killer will kill for >> > example PgSQL database server and cause DB corruption or loss of banking >> > transactions. >> > >> >> This is already happening anyway. The idea is that earlyoom will just >> do it slightly earlier so we have a responsive system when the >> failures happen. Unlike a lot of the other options, earlyoom is just >> doing what the kernel does, just slightly earlier so that the system >> doesn't become unresponsive. >> >> >> >> That is *hugely* valuable for sysadmins >> to be able to recover the systems without power cycling. As a sysadmin >> myself, I *hate* power cycling servers because it takes forever and >> its a lot bigger loss of productivity (and potentially money! > > > Except that slightly earlier is way to early on systems which have lots of memory (see mails from before). It might be. And it might need to be tweaked. Perhaps 6% for SIGTERM and 3% for SIGKILL. Or even 5% and 2.5%. For sure using a percentage of RAM and swap is too simplistic. But it's easy for users to understand. Something more sophisticated, based on kernel pressure stall information would likely be better, and folks are working on that. > > And if a server runs into a oom situation your software is either broken (leaking) or you didn't allocate enough resources for your use case. > > So the fix is not oom killing nor power cycling but to either allocate more memory of it is a VM or buy more if it is a hardware server (or fix the memory leak in your software). That's not a fix either, it's a work around that papers over the problem. Same as earlyoom, except RAM costs money, and may not be an option due to hardware limitations. A modern operating system needs to know better than to allow unprivileged processes to take down the whole system. > And btw we should really update the minimum memory requirements in our documentation, the current ones have nothing to do with reality (if you want a pleasant user experience). Can you be more specific? On getfedora.org it reads: Fedora requires a minimum of 20GB disk, 2GB RAM, to install and run successfully. Double those amounts is recommended. -- Chris Murphy _______________________________________________ devel mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@xxxxxxxxxxxxxxxxxxxxxxx
