Parallelized service starting and stopping tasks

defaults/main.yml

@@ -53,3 +53,29 @@ devture_systemd_service_manager_up_verification_enabled: true
 #
 # We can try to measure this gap and adjust our waiting time accordingly, but we currently don't.
 devture_systemd_service_manager_up_verification_delay_seconds: 15
+
+# devture_systemd_service_manager_parallel_service_setup_enabled controls whether systemd services should start/stop asynchronously.
+# This could significantly reduce the duration for stopping/starting services depending on the number of services on the target host.
+devture_systemd_service_manager_parallel_service_setup_enabled: false
+
+# devture_systemd_service_manager_parallel_jobs specifies how many Ansible processes can run in parallel for the given task.
+#
+# Setting this value to 0 will run as many processes as possible at a time. Note that if this value is set to 0, you may
+# need to increase your host(s) SSH configuration's `MaxSessions` property to facilitate all the connections that will be made in
+# parallel. Additionally, you may need to increase the following parameters if all services cannot start before timing out:
+# - ansible.cfg connection `timeout`
+# - `devture_systemd_service_manager_up_verification_delay_seconds`
+# - `devture_systemd_service_manager_parallel_async_timeout_seconds`
+# - `devture_systemd_service_manager_parallel_job_status_retry_limit`
+devture_systemd_service_manager_parallel_jobs: 16
+
+# devture_systemd_service_manager_parallel_async_timeout_seconds specifies how long to wait before starting the job can timeout.
+devture_systemd_service_manager_parallel_async_timeout_seconds: 60
+
+# devture_systemd_service_manager_parallel_job_status_retry_limit specifies how many attempts the Ansible will check the status
+# of the running jobs before failing the task.
+devture_systemd_service_manager_parallel_job_status_retry_limit: 60
+
+# devture_systemd_service_manager_parallel_job_status_retry_delay_seconds specifies how long Ansible will wait before it checks
+# the status of the running jobs.
+devture_systemd_service_manager_parallel_job_status_retry_delay_seconds: 1

tasks/restart_specified.yml

@@ -22,20 +22,32 @@
 
     - when: devture_systemd_service_manager_services_list_to_work_with | length > 1
       block:
-        - name: Ensure systemd services are stopped
-          ansible.builtin.service:
-            name: "{{ item.name }}"
-            state: stopped
-          with_items: "{{ devture_systemd_service_manager_services_list_to_work_with | sort (attribute='priority,name', reverse=true) }}"
-          when: not ansible_check_mode
+        - when: not devture_systemd_service_manager_parallel_service_setup_enabled
+          block:
+            - name: Ensure systemd services are stopped
+              ansible.builtin.service:
+                name: "{{ item.name }}"
+                state: stopped
+              with_items: "{{ devture_systemd_service_manager_services_list_to_work_with | sort(attribute='priority,name', reverse=true) }}"
+              when: not ansible_check_mode
 
-        - name: Ensure systemd services are started
-          ansible.builtin.service:
-            name: "{{ item.name }}"
-            state: started
-            enabled: "{{ devture_systemd_service_manager_services_autostart_enabled }}"
-          with_items: "{{ devture_systemd_service_manager_services_list_to_work_with | sort (attribute='priority,name') }}"
-          when: not ansible_check_mode
+            - name: Ensure systemd services are started
+              ansible.builtin.service:
+                name: "{{ item.name }}"
+                state: started
+                enabled: "{{ devture_systemd_service_manager_services_autostart_enabled }}"
+              with_items: "{{ devture_systemd_service_manager_services_list_to_work_with | sort(attribute='priority,name') }}"
+              when: not ansible_check_mode
+
+        - when: devture_systemd_service_manager_parallel_service_setup_enabled
+          block:
+            - name: Ensure systemd services are stopped
+              ansible.builtin.include_tasks: "{{ role_path }}/tasks/stop_specified_async.yml"
+              when: not ansible_check_mode
+
+            - name: Ensure systemd services are started
+              ansible.builtin.include_tasks: "{{ role_path }}/tasks/start_specified_async.yml"
+              when: not ansible_check_mode
 
 - when: devture_systemd_service_manager_service_restart_mode == 'one-by-one'
   block:

tasks/start.yml

@@ -6,20 +6,34 @@
 
 - when: devture_systemd_service_manager_service_restart_mode == 'clean-stop-start'
   block:
-    - name: Ensure systemd services are stopped
-      ansible.builtin.service:
-        name: "{{ item.name }}"
-        state: stopped
-      with_items: "{{ devture_systemd_service_manager_services_list | sort (attribute='priority,name', reverse=true) }}"
-      when: not ansible_check_mode
+    - when: not devture_systemd_service_manager_parallel_service_setup_enabled
+      block:
+        - name: Ensure systemd services are stopped
+          ansible.builtin.service:
+            name: "{{ item.name }}"
+            state: stopped
+          with_items: "{{ devture_systemd_service_manager_services_list | sort(attribute='priority,name', reverse=true) }}"
+          when: not ansible_check_mode
 
-    - name: Ensure systemd services are started
-      ansible.builtin.service:
-        name: "{{ item.name }}"
-        state: started
-        enabled: "{{ devture_systemd_service_manager_services_autostart_enabled }}"
-      with_items: "{{ devture_systemd_service_manager_services_list | sort (attribute='priority,name') }}"
-      when: not ansible_check_mode
+        - name: Ensure systemd services are started
+          ansible.builtin.service:
+            name: "{{ item.name }}"
+            state: started
+            enabled: "{{ devture_systemd_service_manager_services_autostart_enabled }}"
+          with_items: "{{ devture_systemd_service_manager_services_list | sort(attribute='priority,name') }}"
+          when: not ansible_check_mode
+
+    - when: devture_systemd_service_manager_parallel_service_setup_enabled
+      vars:
+        devture_systemd_service_manager_services_list_to_work_with: "{{ devture_systemd_service_manager_services_list }}"
+      block:
+        - name: Ensure systemd services are stopped
+          ansible.builtin.include_tasks: "{{ role_path }}/tasks/stop_specified_async.yml"
+          when: not ansible_check_mode
+
+        - name: Ensure systemd services are started
+          ansible.builtin.include_tasks: "{{ role_path }}/tasks/start_specified_async.yml"
+          when: not ansible_check_mode
 
 - when: devture_systemd_service_manager_service_restart_mode == 'one-by-one'
   block:

tasks/start_specified_async.yml

@@ -0,0 +1,40 @@
+---
+
+# Suppress 'risky-shell-pipe' lint error due to the required fix `set -o pipefail` not being supported by all shells.
+# Additionally, echo commands generally should not fail.
+- name: Ensure systemd services are started
+  ansible.builtin.shell: >
+    echo "{{ devture_systemd_service_manager_services_list_to_work_with | sort(attribute='priority,name') | join(' ', attribute='name') }}"
+    |
+    xargs -P {{ devture_systemd_service_manager_parallel_jobs }} -d ' ' -I '{}'
+    ansible {{ inventory_hostname }} -i {{ inventory_file }} -m service {{ '' if become is undefined else '--become' }}
+    -a "
+    name={}
+    state=started
+    enabled={{ devture_systemd_service_manager_services_autostart_enabled }}
+    "
+  tags:
+    - skip_ansible_lint
+  register: "start_service_job_status"
+  delegate_to: localhost
+  become: false
+  async: "{{ devture_systemd_service_manager_parallel_async_timeout_seconds }}"
+  poll: 0
+  changed_when: false
+
+- name: Check job status for started services
+  ansible.builtin.async_status:
+    jid: "{{ start_service_job_status.ansible_job_id }}"
+  register: start_service_job_status
+  until: start_service_job_status.finished
+  retries: "{{ devture_systemd_service_manager_parallel_job_status_retry_limit }}"
+  delay: "{{ devture_systemd_service_manager_parallel_job_status_retry_delay_seconds }}"
+  delegate_to: localhost
+  become: false
+
+- name: Cleanup async job temp file
+  ansible.builtin.async_status:
+    jid: "{{ start_service_job_status.ansible_job_id }}"
+    mode: "cleanup"
+  delegate_to: localhost
+  become: false

tasks/stop_specified.yml

@@ -8,4 +8,9 @@
   ansible.builtin.service:
     name: "{{ item.name }}"
     state: stopped
-  with_items: "{{ devture_systemd_service_manager_services_list_to_work_with | sort (attribute='priority,name', reverse=true) }}"
+  with_items: "{{ devture_systemd_service_manager_services_list_to_work_with | sort(attribute='priority,name', reverse=true) }}"
+  when: not devture_systemd_service_manager_parallel_service_setup_enabled
+
+- name: Ensure systemd services are stopped
+  ansible.builtin.include_tasks: "{{ role_path }}/tasks/stop_specified_async.yml"
+  when: devture_systemd_service_manager_parallel_service_setup_enabled

tasks/stop_specified_async.yml

@@ -0,0 +1,39 @@
+---
+
+# Suppress 'risky-shell-pipe' lint error due to the required fix `set -o pipefail` not being supported by all shells.
+# Additionally, echo commands generally should not fail.
+- name: Ensure systemd services are stopped
+  ansible.builtin.shell: >
+    echo "{{ devture_systemd_service_manager_services_list_to_work_with | sort(attribute='priority,name', reverse=true) | join(' ', attribute='name') }}"
+    |
+    xargs -P {{ devture_systemd_service_manager_parallel_jobs }} -d ' ' -I '{}'
+    ansible {{ inventory_hostname }} -i {{ inventory_file }} -m service {{ '' if become is undefined else '--become' }}
+    -a "
+    name={}
+    state=stopped
+    "
+  tags:
+    - skip_ansible_lint
+  register: "stop_service_job_status"
+  delegate_to: localhost
+  become: false
+  async: "{{ devture_systemd_service_manager_parallel_async_timeout_seconds }}"
+  poll: 0
+  changed_when: false
+
+- name: Check job status for stopped services
+  ansible.builtin.async_status:
+    jid: "{{ stop_service_job_status.ansible_job_id }}"
+  register: stop_service_job_status
+  until: stop_service_job_status.finished
+  retries: "{{ devture_systemd_service_manager_parallel_job_status_retry_limit }}"
+  delay: "{{ devture_systemd_service_manager_parallel_job_status_retry_delay_seconds }}"
+  delegate_to: localhost
+  become: false
+
+- name: Cleanup async job temp file
+  ansible.builtin.async_status:
+    jid: "{{ stop_service_job_status.ansible_job_id }}"
+    mode: "cleanup"
+  delegate_to: localhost
+  become: false