Added NUMA detection and configure mongodb to work correctly using NUMA

roles/mongodb/tasks/configure-mongodb-numa.yml

@@ -0,0 +1,95 @@
+# Copyright (c) 2025, Itential, Inc
+# GNU General Public License v3.0+ (see LICENSE or https://www.gnu.org/licenses/gpl-3.0.txt)
+---
+
+- name: Detect NUMA nodes
+  ansible.builtin.shell:
+    cmd: |
+      if [ -d /sys/devices/system/node ]; then
+        ls -d /sys/devices/system/node/node[0-9]* 2>/dev/null | wc -l
+      else
+        echo 0
+      fi
+  args:
+    executable: /bin/bash
+  register: mongodb_numa_nodes
+  changed_when: false
+
+- name: Set NUMA enabled fact
+  ansible.builtin.set_fact:
+    mongodb_numa_enabled: "{{ (mongodb_numa_nodes.stdout | int) > 1 }}"
+
+- name: Enable NUMA settings if multiple NUMA nodes detected
+  when: mongodb_numa_enabled
+  block:
+    - name: Ensure numactl is installed when NUMA is enabled
+      ansible.builtin.package:
+        name: numactl
+        state: present
+
+    - name: Discover numactl path
+      ansible.builtin.shell:
+        cmd: "command -v numactl || true"
+      args:
+        executable: /bin/bash
+      register: mongodb_numactl_path_result
+      changed_when: false
+      become: true
+
+    - name: Discover mongod path
+      ansible.builtin.shell:
+        cmd: "command -v mongod || true"
+      args:
+        executable: /bin/bash
+      register: mongodb_mongod_path_result
+      changed_when: false
+
+    - name: Set NUMA helper facts
+      ansible.builtin.set_fact:
+        mongodb_numactl_path: "{{ mongodb_numactl_path_result.stdout | default('', true) }}"
+        mongodb_mongod_path: "{{ mongodb_mongod_path_result.stdout | default('/usr/bin/mongod', true) }}"
+        mongodb_numactl_present: "{{ (mongodb_numactl_path_result.stdout | default('', true) | length) > 0 }}"
+
+    - name: Apply NUMA sysctl settings
+      ansible.posix.sysctl:
+        name: vm.zone_reclaim_mode
+        value: "{{ mongodb_vm_zone_reclaim_mode }}"
+        state: present
+        sysctl_file: "{{ mongodb_sysctl_file }}"
+        reload: true
+
+    - name: Disable kernel NUMA balancing
+      ansible.posix.sysctl:
+        name: kernel.numa_balancing
+        value: "0"
+        state: present
+        sysctl_file: "{{ mongodb_sysctl_file }}"
+        reload: true
+
+    - name: Ensure mongod systemd drop-in directory exists
+      ansible.builtin.file:
+        path: /etc/systemd/system/mongod.service.d
+        state: directory
+        mode: "0755"
+      when: mongodb_numactl_present
+
+    - name: Configure mongod to run with numactl interleave
+      ansible.builtin.copy:
+        dest: /etc/systemd/system/mongod.service.d/numa.conf
+        mode: "0644"
+        content: |
+          [Service]
+          ExecStart=
+          ExecStart={{ mongodb_numactl_path }} --interleave=all {{ mongodb_mongod_path }} --config {{ mongodb_conf_file }}
+      register: mongodb_numa_dropin
+      when: mongodb_numactl_present
+
+    - name: Reload systemd and restart mongod to apply NUMA settings
+      ansible.builtin.systemd:
+        name: mongod
+        state: restarted
+        daemon_reload: true
+      when:
+        - mongodb_numactl_present
+        - mongodb_numa_dropin is defined
+        - mongodb_numa_dropin.changed

roles/mongodb/tasks/install-mongodb.yml

@@ -68,6 +68,11 @@
     file: configure-mongodb-logrotate.yml
   tags: configure_logrotate
 
+- name: Configure NUMA for MongoDB
+  ansible.builtin.include_tasks:
+    file: configure-mongodb-numa.yml
+  tags: configure_numa
+
 # Check if firewalld is running, if it is then open the appropriate ports
 - name: Gather service facts
   ansible.builtin.service_facts: