Enable graceful shutdown for services
1] Process using uwsgi:
uwsgi services doesn't support for graceful shutting down [1].
It requires some changes in unit files [2] including adding below
graceful shutdown hook and changing KillSignal:
--hook-master-start "unix_signal:15 gracefully_kill_them_all
All the steps and changes required are specified in etherpad [1].
2] Non uwsgi services needs below changes:
In [service] section:
a. Add KillMode = process
b. Add TimeoutStopSec = infinity
NOTE:
Creating unit file for services other than uwsgi is handled by the
'write_user_unit_file' function [3]. This function is common for all
the services so this patch adds the above mentioned parameters for
services using ServiceLauncher also though they don't require.
Added a new stackrc variable WORKER_TIMEOUT which is required to add
graceful shutdown support to uwsgi services. It will be set as a value
to 'worker-reload-mercy' [4] in uwsgi file of service. The default
value set to this variable is 90.
[1] https://etherpad.openstack.org/p/uwsgi-issues
[2] https://www.freedesktop.org/software/systemd/man/systemd.kill.html
[3] https://github.com/openstack-dev/devstack/blob/2967ca3dfd0d64970dfa5dfa7ac2330ee7aa90ed/functions-common#L1439-L1461
[4] http://uwsgi-docs.readthedocs.io/en/latest/Options.html#worker-reload-mercy
Co-Authored-By: Dinesh Bhor <dinesh.bhor@nttdata.com>
Change-Id: Ia95291325ce4858b47102dd49504250183f339ab
diff --git a/functions-common b/functions-common
index a5f770f..52f53ef 100644
--- a/functions-common
+++ b/functions-common
@@ -1451,6 +1451,8 @@
iniset -sudo $unitfile "Unit" "Description" "Devstack $service"
iniset -sudo $unitfile "Service" "User" "$user"
iniset -sudo $unitfile "Service" "ExecStart" "$command"
+ iniset -sudo $unitfile "Service" "KillMode" "process"
+ iniset -sudo $unitfile "Service" "TimeoutStopSec" "infinity"
if [[ -n "$group" ]]; then
iniset -sudo $unitfile "Service" "Group" "$group"
fi
@@ -1473,7 +1475,7 @@
iniset -sudo $unitfile "Service" "User" "$user"
iniset -sudo $unitfile "Service" "ExecStart" "$command"
iniset -sudo $unitfile "Service" "Type" "notify"
- iniset -sudo $unitfile "Service" "KillSignal" "SIGQUIT"
+ iniset -sudo $unitfile "Service" "KillMode" "process"
iniset -sudo $unitfile "Service" "Restart" "always"
iniset -sudo $unitfile "Service" "NotifyAccess" "all"
iniset -sudo $unitfile "Service" "RestartForceExitStatus" "100"
diff --git a/lib/apache b/lib/apache
index dfca25a..39d5b7b 100644
--- a/lib/apache
+++ b/lib/apache
@@ -260,10 +260,15 @@
# Set die-on-term & exit-on-reload so that uwsgi shuts down
iniset "$file" uwsgi die-on-term true
iniset "$file" uwsgi exit-on-reload true
+ # Set worker-reload-mercy so that worker will not exit till the time
+ # configured after graceful shutdown
+ iniset "$file" uwsgi worker-reload-mercy $WORKER_TIMEOUT
iniset "$file" uwsgi enable-threads true
iniset "$file" uwsgi plugins python
# uwsgi recommends this to prevent thundering herd on accept.
iniset "$file" uwsgi thunder-lock true
+ # Set hook to trigger graceful shutdown on SIGTERM
+ iniset "$file" uwsgi hook-master-start "unix_signal:15 gracefully_kill_them_all"
# Override the default size for headers from the 4k default.
iniset "$file" uwsgi buffer-size 65535
# Make sure the client doesn't try to re-use the connection.
@@ -316,6 +321,11 @@
iniset "$file" uwsgi plugins python
# uwsgi recommends this to prevent thundering herd on accept.
iniset "$file" uwsgi thunder-lock true
+ # Set hook to trigger graceful shutdown on SIGTERM
+ iniset "$file" uwsgi hook-master-start "unix_signal:15 gracefully_kill_them_all"
+ # Set worker-reload-mercy so that worker will not exit till the time
+ # configured after graceful shutdown
+ iniset "$file" uwsgi worker-reload-mercy $WORKER_TIMEOUT
# Override the default size for headers from the 4k default.
iniset "$file" uwsgi buffer-size 65535
# Make sure the client doesn't try to re-use the connection.
diff --git a/stackrc b/stackrc
index 3591994..e936b33 100644
--- a/stackrc
+++ b/stackrc
@@ -778,6 +778,9 @@
# Service graceful shutdown timeout
SERVICE_GRACEFUL_SHUTDOWN_TIMEOUT=${SERVICE_GRACEFUL_SHUTDOWN_TIMEOUT:-5}
+# Service graceful shutdown timeout
+WORKER_TIMEOUT=${WORKER_TIMEOUT:-90}
+
# Support alternative yum -- in future Fedora 'dnf' will become the
# only supported installer, but for now 'yum' and 'dnf' are both
# available in parallel with compatible CLIs. Allow manual switching