Resource parameters are not needed in the env section. Change the order of the app and db.

Config/WordpressExample/docker-compose.example.yml

@@ -17,34 +17,6 @@
 
 services:
 
-  db:
-    container_name: wp-db
-    image: mariadb:lts
-    restart: always
-    volumes:
-      - ../../Volumes/WordPress/mariadb:/var/lib/mysql
-    healthcheck:
-      test: ["CMD", "healthcheck.sh", "--connect", "--innodb_initialized"]
-      start_period: 5s
-      interval: 5s
-      timeout: 5s
-      retries: 10
-    environment:
-      # https://mariadb.com/docs/server/server-management/automated-mariadb-deployment-and-administration/docker-and-mariadb/mariadb-server-docker-official-image-environment-variables
-      MARIADB_DATABASE: $MARIADB_DATABASE
-      MARIADB_USER: $MARIADB_USER
-      MARIADB_PASSWORD: MARIADB_PASSWORD
-      MARIADB_ROOT_PASSWORD: $MARIADB_ROOT_PASSWORD
-      MARIADB_AUTO_UPGRADE: $MARIADB_AUTO_UPGRADE
-      WP_CPU_DB: $WP_CPU_DB
-      WP_MEM_DB: $WP_MEM_DB
-    deploy:
-      mode: global
-      resources:
-        limits:
-          cpus: $WP_CPU_DB
-          memory: $WP_MEM_DB
-
   app:
     container_name: wp-app
     image: wordpress:latest
@@ -70,11 +42,35 @@ services:
       WORDPRESS_DB_USER: root
       WORDPRESS_DB_PASSWORD: $MARIADB_ROOT_PASSWORD
       WORDPRESS_DEBUG: $WORDPRESS_DEBUG
-      WP_CPU: $WP_CPU
-      WP_MEM: $WP_MEM
     deploy:
       mode: global
       resources:
         limits:
           cpus: $WP_CPU
           memory: $WP_MEM
+
+  db:
+    container_name: wp-db
+    image: mariadb:lts
+    restart: always
+    volumes:
+      - ../../Volumes/WordPress/mariadb:/var/lib/mysql
+    healthcheck:
+      test: ["CMD", "healthcheck.sh", "--connect", "--innodb_initialized"]
+      start_period: 5s
+      interval: 5s
+      timeout: 5s
+      retries: 10
+    environment:
+      # https://mariadb.com/docs/server/server-management/automated-mariadb-deployment-and-administration/docker-and-mariadb/mariadb-server-docker-official-image-environment-variables
+      MARIADB_DATABASE: $MARIADB_DATABASE
+      MARIADB_USER: $MARIADB_USER
+      MARIADB_PASSWORD: MARIADB_PASSWORD
+      MARIADB_ROOT_PASSWORD: $MARIADB_ROOT_PASSWORD
+      MARIADB_AUTO_UPGRADE: $MARIADB_AUTO_UPGRADE
+    deploy:
+      mode: global
+      resources:
+        limits:
+          cpus: $WP_CPU_DB
+          memory: $WP_MEM_DB