** Patch added: "lp1846787-systemd-xenial.debdiff" https://bugs.launchpad.net/ubuntu/+source/dbus/+bug/1846787/+attachment/5295137/+files/lp1846787-systemd-xenial.debdiff
-- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to systemd in Ubuntu. https://bugs.launchpad.net/bugs/1846787 Title: systemd-logind leaves leftover sessions and scope files Status in dbus package in Ubuntu: Fix Released Status in systemd package in Ubuntu: Fix Released Status in dbus source package in Xenial: In Progress Status in systemd source package in Xenial: In Progress Bug description: [Impact] Scope file leakage can cause SSH delays and reduce performance in systemd [Description] The current systemd-logind version present in Xenial can leave abandoned SSH sessions and scope files in cases where the host sees a lot of concurrent SSH connections. These leftover sessions can slow down systemd performance greatly, and can have an impact on sshd handling a great number of concurrent connections. To fix this issue, patches are needed in both dbus and systemd. These improve the performance of the communication between dbus and systemd, so that they can handle a better volume of events (e.g. SSH logins). All of those patches are already present from Bionic onwards, so we only need those fixes for Xenial. == Systemd == Upstream patches: - core: use an AF_UNIX/SOCK_DGRAM socket for cgroup agent notification (d8fdc62037b5) $ git describe --contains d8fdc62037b5 v230~71^2~2 $ rmadison systemd systemd | 229-4ubuntu4 | xenial | source, ... systemd | 229-4ubuntu21.21 | xenial-security | source, ... systemd | 229-4ubuntu21.22 | xenial-updates | source, ... <-------- systemd | 237-3ubuntu10 | bionic | source, ... systemd | 237-3ubuntu10.29 | bionic-security | source, ... systemd | 237-3ubuntu10.29 | bionic-updates | source, ... systemd | 237-3ubuntu10.31 | bionic-proposed | source, ... == DBus == Upstream patches: - Only read one message at a time if there are fds pending (892f084eeda0) - bus: Fix timeout restarts (529600397bca) - DBusMainLoop: ensure all required timeouts are restarted (446b0d9ac75a) $ git describe --contains 892f084eeda0 529600397bca 446b0d9ac75a dbus-1.11.10~44 dbus-1.11.10~45 dbus-1.11.16~2 $ rmadison dbus dbus | 1.10.6-1ubuntu3 | xenial | source, ... dbus | 1.10.6-1ubuntu3.4 | xenial-security | source, ... dbus | 1.10.6-1ubuntu3.4 | xenial-updates | source, ... <-------- dbus | 1.12.2-1ubuntu1 | bionic | source, ... dbus | 1.12.2-1ubuntu1.1 | bionic-security | source, ... dbus | 1.12.2-1ubuntu1.1 | bionic-updates | source, ... [Test Case] 1) Simulate a lot of concurrent SSH connections with e.g. a for loop: multipass@xenial-logind:~$ for i in {1..1000}; do sleep 0.1; ssh localhost sleep 1 & done 2) Check for leaked sessions in /run/systemd/system/: multipass@xenial-logind:~$ ls -ld /run/systemd/system/session-*.scope* drwxr-xr-x 2 root root 160 Oct 4 15:34 /run/systemd/system/session-103.scope.d drwxr-xr-x 2 root root 160 Oct 4 15:34 /run/systemd/system/session-104.scope.d drwxr-xr-x 2 root root 160 Oct 4 15:34 /run/systemd/system/session-105.scope.d drwxr-xr-x 2 root root 160 Oct 4 15:34 /run/systemd/system/session-106.scope.d drwxr-xr-x 2 root root 160 Oct 4 15:34 /run/systemd/system/session-110.scope.d drwxr-xr-x 2 root root 160 Oct 4 15:34 /run/systemd/system/session-111.scope.d drwxr-xr-x 2 root root 160 Oct 4 15:34 /run/systemd/system/session-112.scope.d drwxr-xr-x 2 root root 160 Oct 4 15:34 /run/systemd/system/session-113.scope.d drwxr-xr-x 2 root root 160 Oct 4 15:34 /run/systemd/system/session-114.scope.d drwxr-xr-x 2 root root 160 Oct 4 15:34 /run/systemd/system/session-115.scope.d drwxr-xr-x 2 root root 160 Oct 4 15:34 /run/systemd/system/session-116.scope.d drwxr-xr-x 2 root root 160 Oct 4 15:34 /run/systemd/system/session-117.scope.d drwxr-xr-x 2 root root 160 Oct 4 15:34 /run/systemd/system/session-118.scope.d drwxr-xr-x 2 root root 160 Oct 4 15:34 /run/systemd/system/session-119.scope.d drwxr-xr-x 2 root root 160 Oct 4 15:34 /run/systemd/system/session-120.scope.d drwxr-xr-x 2 root root 160 Oct 4 15:34 /run/systemd/system/session-121.scope.d drwxr-xr-x 2 root root 160 Oct 4 15:34 /run/systemd/system/session-122.scope.d drwxr-xr-x 2 root root 160 Oct 4 15:34 /run/systemd/system/session-123.scope.d drwxr-xr-x 2 root root 160 Oct 4 15:34 /run/systemd/system/session-126.scope.d drwxr-xr-x 2 root root 160 Oct 4 15:34 /run/systemd/system/session-131.scope.d drwxr-xr-x 2 root root 160 Oct 4 15:34 /run/systemd/system/session-134.scope.d ... [Regression Potential] The regression potential is low, as these patches have seen extensive testing both upstream and in more recent releases of Ubuntu. Nonetheless, these new packages will be rigorously tested through autopkgtest to avoid any possible Xenial-specific regressions. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/dbus/+bug/1846787/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
