Docker Compose Resource Optimization
Configures resource allocation, constraints, and scaling for PHP application stacks.
Resource Allocation Overview
┌─────────────────────────────────────────────────────────────────┐
│ PHP STACK RESOURCE DISTRIBUTION (4GB Host) │
├─────────────────────────────────────────────────────────────────┤
│ PHP-FPM: ████████████████████░░░░░░░░░░ 1024MB (25%) │
│ MySQL: ████████████████████████░░░░░░ 1536MB (38%) │
│ Redis: ████████░░░░░░░░░░░░░░░░░░░░░░ 512MB (13%) │
│ Nginx: ████░░░░░░░░░░░░░░░░░░░░░░░░░░ 256MB (6%) │
│ RabbitMQ: ████████░░░░░░░░░░░░░░░░░░░░░░ 512MB (13%) │
│ System: ████░░░░░░░░░░░░░░░░░░░░░░░░░░ 256MB (6%) │
└─────────────────────────────────────────────────────────────────┘
Recommended Resource Limits
| Service |
Memory Limit |
Memory Reservation |
CPU Limit |
CPU Reservation |
| PHP-FPM |
512MB-1GB |
256MB |
1.0 |
0.25 |
| Nginx |
128MB-256MB |
64MB |
0.5 |
0.1 |
| MySQL |
1GB-2GB |
512MB |
1.5 |
0.5 |
| PostgreSQL |
1GB-2GB |
512MB |
1.5 |
0.5 |
| Redis |
256MB-512MB |
128MB |
0.5 |
0.1 |
| RabbitMQ |
512MB-1GB |
256MB |
1.0 |
0.25 |
Service Configurations
PHP-FPM
php-fpm:
deploy:
resources:
limits: { cpus: "1.0", memory: 1024M }
reservations: { cpus: "0.25", memory: 256M }
replicas: 2
tmpfs: ["/tmp:size=64M"]
healthcheck:
test: ["CMD", "php-fpm-healthcheck"]
interval: 30s
timeout: 5s
start_period: 10s
MySQL
mysql:
deploy:
resources:
limits: { cpus: "1.5", memory: 2048M }
reservations: { cpus: "0.5", memory: 512M }
shm_size: "256m"
command: >
--innodb-buffer-pool-size=1G --innodb-log-file-size=256M
--max-connections=200 --tmp-table-size=64M
ulimits:
nofile: { soft: 65536, hard: 65536 }
Redis
redis:
deploy:
resources:
limits: { cpus: "0.5", memory: 512M }
reservations: { cpus: "0.1", memory: 128M }
command: redis-server --maxmemory 384mb --maxmemory-policy allkeys-lru --save "" --appendonly no
tmpfs: ["/data:size=384M"]
RabbitMQ
rabbitmq:
deploy:
resources:
limits: { cpus: "1.0", memory: 1024M }
reservations: { cpus: "0.25", memory: 256M }
environment:
RABBITMQ_VM_MEMORY_HIGH_WATERMARK: 0.6
RABBITMQ_DISK_FREE_LIMIT: 128MB
Logging Configuration
logging:
driver: json-file
options:
max-size: "10m"
max-file: "3"
| Service |
max-size |
max-file |
Total Disk |
| PHP-FPM |
10m |
3 |
30MB |
| Nginx |
20m |
5 |
100MB |
| MySQL |
10m |
3 |
30MB |
| Redis |
5m |
2 |
10MB |
tmpfs for Ephemeral Data
tmpfs:
- /tmp:size=64M,mode=1777
- /app/var/cache:size=128M
- /app/var/log:size=32M
Benefits: faster I/O, no disk writes, auto-cleaned on restart.
shm_size for Databases
postgres:
shm_size: "256m" # shared_buffers, WAL buffers, lock tables
mysql:
shm_size: "256m" # InnoDB buffer pool, temp tables
ulimits Configuration
| ulimit |
Default |
Recommended |
Purpose |
| nofile |
1024 |
65536 |
Max open files/sockets |
| nproc |
1024 |
4096 |
Max processes |
| memlock |
64KB |
unlimited |
Memory locking (Redis) |
Scaling with Replicas
php-fpm:
deploy:
replicas: 3
endpoint_mode: dnsrr
resources:
limits: { cpus: "0.5", memory: 512M }
# Total: 1.5 CPU, 1536M memory across 3 replicas
# Nginx resolves php-fpm to all replicas via DNS round-robin
Before/After Comparison
| Metric |
No Limits |
With Limits |
Improvement |
| OOM kills |
Frequent |
Rare |
Predictable |
| Noisy neighbor |
Common |
Prevented |
Isolated |
| Memory waste |
30-50% |
< 10% |
-80% waste |
| Log disk usage |
Unbounded |
< 200MB |
Controlled |
| Recovery time |
Minutes |
Seconds |
Faster restarts |
Generation Instructions
- Inventory services: List all containers in the stack
- Assess host resources: Total CPU and memory available
- Allocate proportionally: Database > App > Cache > Proxy
- Set limits and reservations: Limits cap usage, reservations guarantee minimum
- Configure logging: Prevent unbounded disk growth
- Add health checks: Enable automatic recovery
- Test under load: Verify no OOM kills or throttling
dykyi-roman