From 6a7428898f7fa7a0d46e1de60ca57e7ec6ce14c9 Mon Sep 17 00:00:00 2001 From: Sai Sindhur Malleni Date: Tue, 19 Sep 2017 15:12:35 -0400 Subject: Bump fs.inotify.max_user_instances for scale Since each dnsmasq process consumes one inotify socket, the default value of fs.inotify.max_user_instances which is 128 lets us scale to only around a 116 neutron subnets (a few other sockets are used by other processes on the system). Since, we need to provide better defaults, this patch proposes to bump this value to 1024 by default, while giving the user a way to cahnge it. Based on https://unix.stackexchange.com/a/13757 each inotify watch takes 1KB of memory and we have fs.inotify.max_user_watches set to 8192 by default. This means that even in the worst case we won't be using more than 8MB of memory. Bumping the fs.inotify.max_user_instances value to 1024 is safe because there is fs.inotify.max_user_watches which caps the total number of files that can be watched by all the inotify instances a user has. Related Bugs: https://bugzilla.redhat.com/show_bug.cgi?id=1474515 https://bugzilla.redhat.com/show_bug.cgi?id=1491505 Change-Id: I39664312bf6cf06f1e1ca2e86ffd86fb9a4582ad Closes-Bug: 1718266 (cherry picked from commit d2d0c3ff00de9b62382193d942239d543aa9499f) --- puppet/services/kernel.yaml | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'puppet') diff --git a/puppet/services/kernel.yaml b/puppet/services/kernel.yaml index 011ec037..1c2da401 100644 --- a/puppet/services/kernel.yaml +++ b/puppet/services/kernel.yaml @@ -60,6 +60,11 @@ parameters: ARP cache. The garbage collector will always run if there are more than this number of entries in the cache. type: number + InotifyIntancesMax: + default: 1024 + description: Configures sysctl fs.inotify.max_user_instances key + type: number + outputs: role_data: @@ -129,5 +134,9 @@ outputs: value: {get_param: NeighbourGcThreshold2} net.ipv4.neigh.default.gc_thresh3: value: {get_param: NeighbourGcThreshold3} + # set inotify value for neutron/dnsmasq scale + fs.inotify.max_user_instances: + value: {get_param: InotifyIntancesMax} + step_config: | include ::tripleo::profile::base::kernel -- cgit 1.2.3-korg