4 ms·

Your assumptions are wrong. Glibc is faster (and better) than musl. Systemd is faster (and better) than SYSV init scripts. Moreover, for example, I can update

by lisivka 11y ago

Your assumptions are wrong. Glibc is faster (and better) than musl. Systemd is faster (and better) than SYSV init scripts. Moreover, for example, I can update my running containers based on Fedora 23 without restarting container, by issuing "dnf update", which will download updated package from local server, which is much faster that to build container, publish it to hub, download it back, restart container (even when only static files are changed).

_Marak_ 11y ago
So the overhead of using Docker is still to great. Thanks for the information.
- cyphar 11y ago
  Docker has very little overhead (apart from all of the setup required to start a container). In principle it has no overhead, but Linux memory accounting has implicit memory overhead (this is a kernel issue, not a Docker issue).
sandGorgon 11y ago
whoa - you have a container with working systemd ? I thought that was an unfixed bug - https://github.com/docker/docker/pull/5773 https://github.com/docker/docker/pull/5773 and https://github.com/docker/docker/issues/3629 https://github.com/docker/docker/issues/3629
- lisivka 11y ago
  Yep. It have some quirks (hard to shutdown properly), but it works. [vlisivka@apollo5 docker-centos7-systemd-unpriv]$ ./enter.sh [root@e3c3dd7539ad /]# ps ax PID TTY STAT TIME COMMAND 1 ? Ss 0:00 /usr/lib/systemd/systemd 71 ? Ss 0:00 /usr/lib/systemd/systemd-journald 74 ? Ss 0:00 bash 92 ? R+ 0:00 ps ax https://github.com/vlisivka/docker-centos7-systemd-unpriv https://github.com/vlisivka/docker-centos7-systemd-unpriv
  - sandGorgon 11y ago
    Hmm.. It's not worth it for me right now. I am using supervisord which works brilliantly
bluejekyll 11y ago
> Glibc is faster (and better) Faster is objective, and in most cases correct. Glibc has a lot mor optimization over the years. Better is subjective and completely depends on your use case: http://www.etalabs.net/compare_libcs.html http://www.etalabs.net/compare_libcs.html Similar point to systemd, it is kind of misleading to say that it's faster, it is parallel and event driven, which definitely makes it's end to end time shorter on parallel hardware. And again better is subjective, it's so much more complex that it might not always be the right choice. Also, why use systemd inside a container at all? There's just one process in there usually.

by lisivka 11y ago

_Marak_ 11y ago

So the overhead of using Docker is still to great. Thanks for the information.

cyphar 11y ago
Docker has very little overhead (apart from all of the setup required to start a container). In principle it has no overhead, but Linux memory accounting has implicit memory overhead (this is a kernel issue, not a Docker issue).

sandGorgon 11y ago

whoa - you have a container with working systemd ? I thought that was an unfixed bug - https://github.com/docker/docker/pull/5773 https://github.com/docker/docker/pull/5773 and https://github.com/docker/docker/issues/3629 https://github.com/docker/docker/issues/3629

lisivka 11y ago
Yep. It have some quirks (hard to shutdown properly), but it works. [vlisivka@apollo5 docker-centos7-systemd-unpriv]$ ./enter.sh [root@e3c3dd7539ad /]# ps ax PID TTY STAT TIME COMMAND 1 ? Ss 0:00 /usr/lib/systemd/systemd 71 ? Ss 0:00 /usr/lib/systemd/systemd-journald 74 ? Ss 0:00 bash 92 ? R+ 0:00 ps ax https://github.com/vlisivka/docker-centos7-systemd-unpriv https://github.com/vlisivka/docker-centos7-systemd-unpriv
- sandGorgon 11y ago
  Hmm.. It's not worth it for me right now. I am using supervisord which works brilliantly

bluejekyll 11y ago

> Glibc is faster (and better) Faster is objective, and in most cases correct. Glibc has a lot mor optimization over the years. Better is subjective and completely depends on your use case: http://www.etalabs.net/compare_libcs.html http://www.etalabs.net/compare_libcs.html Similar point to systemd, it is kind of misleading to say that it's faster, it is parallel and event driven, which definitely makes it's end to end time shorter on parallel hardware. And again better is subjective, it's so much more complex that it might not always be the right choice. Also, why use systemd inside a container at all? There's just one process in there usually.