Set vm.max_map_count kernel parameter on MongoDB servers

docs/mongodb_guide.md

@@ -138,6 +138,12 @@ These variables apply to advanced situations.
 | `mongodb_mongod_service_delay` | Integer | The time in seconds between retries when starting the mongod service. | 10 |
 | `mongodb_status_poll` | Integer | The maximum number of times to query for the replicaset status before the set converges or we fail. | 3 |
 | `mongodb_status_interval` | Integer | The number of seconds to wait between polling executions. | 10 |
+| `mongodb_sysctl_file` | String | The name of the MongoDB sysctl file | /etc/sysctl.d/98-mongodb.conf |
+| `mongodb_net_ipv4_tcp_keepalive_time` | Integer | Time (in seconds) that a TCP connection remains idle before the kernel starts sending keepalive probes to verify the connection is still alive. | 300 |
+| `mongodb_net_core_somaxconn` | Integer | Controls the backlog queue size for incoming connections. When the queue is full, new connection attempts are rejected. | 65535 |
+| `mongodb_vm_zone_reclaim_mode` | Integer | Controls whether the kernel reclaims memory from local zones before allocating from remote NUMA nodes. | 0 |
+| `mongodb_vm_swappiness` | Integer | Balances between swapping out anonymous pages (process memory) versus dropping page cache (file system buffers). | 1 |
+| `mongodb_vm_max_map_count` | Integer | Maximum number of memory map areas (virtual memory areas/VMAs) a process can create. | 262144 |
 
 ## Configuring TLS
 

roles/mongodb/defaults/main/kernel_params.yml

@@ -0,0 +1,10 @@
+# Copyright (c) 2024, Itential, Inc
+# GNU General Public License v3.0+ (see LICENSE or https://www.gnu.org/licenses/gpl-3.0.txt)
+---
+# Kernel parameters
+mongodb_sysctl_file: /etc/sysctl.d/98-mongodb.conf
+mongodb_net_ipv4_tcp_keepalive_time: 300
+mongodb_net_core_somaxconn: 65535
+mongodb_vm_zone_reclaim_mode: 0
+mongodb_vm_swappiness: 1
+mongodb_vm_max_map_count: 262144

roles/mongodb/tasks/install-adjust-kernel-params.yml → roles/mongodb/tasks/adjust-kernel-params.yml

@@ -17,34 +17,39 @@
 - name: Adjust keepalive
   ansible.posix.sysctl:
     name: net.ipv4.tcp_keepalive_time
-    value: 300
-
-- name: Disable zone reclaim mode
-  ansible.posix.sysctl:
-    name: vm.zone_reclaim_mode
-    value: 0
+    value: "{{ mongodb_net_ipv4_tcp_keepalive_time }}"
+    state: present
+    sysctl_file: "{{ mongodb_sysctl_file }}"
+    reload: true
 
 - name: Increase throughput settings
   ansible.posix.sysctl:
     name: net.core.somaxconn
-    value: 65535
+    value: "{{ mongodb_net_core_somaxconn }}"
+    state: present
+    sysctl_file: "{{ mongodb_sysctl_file }}"
+    reload: true
+
+- name: Disable zone reclaim mode
+  ansible.posix.sysctl:
+    name: vm.zone_reclaim_mode
+    value: "{{ mongodb_vm_zone_reclaim_mode }}"
+    state: present
+    sysctl_file: "{{ mongodb_sysctl_file }}"
+    reload: true
 
 - name: Set vm swappiness
   ansible.posix.sysctl:
     name: vm.swappiness
-    value: 1
+    value: "{{ mongodb_vm_swappiness }}"
+    state: present
+    sysctl_file: "{{ mongodb_sysctl_file }}"
+    reload: true
 
-# Set Soft User Limits
-- name: Set number of procs
-  community.general.pam_limits:
-    domain: mongod
-    limit_type: soft
-    limit_item: nproc
-    value: 32000
-
-- name: Set number of files
-  community.general.pam_limits:
-    domain: mongod
-    limit_type: soft
-    limit_item: nofile
-    value: 64000
+- name: Set vm max_map_count
+  ansible.posix.sysctl:
+    name: vm.max_map_count
+    value: "{{ mongodb_vm_max_map_count }}"
+    state: present
+    sysctl_file: "{{ mongodb_sysctl_file }}"
+    reload: true

roles/mongodb/tasks/install-mongodb.yml

@@ -53,7 +53,7 @@
 
 - name: Adjust Kernel parameters
   ansible.builtin.import_tasks:
-    file: install-adjust-kernel-params.yml
+    file: adjust-kernel-params.yml
 
 - name: Configure SELinux
   ansible.builtin.include_tasks: