perf: improve worker and storage throughput

docker/.env.production.example

@@ -21,10 +21,11 @@ ADMIN_EMAIL=admin@example.com
 ADMIN_USERNAME=admin
 ADMIN_PASSWORD=replace-with-a-strong-admin-password
 
-# A four-core host should start with two image jobs per process.
-DATABASE_MAX_CONNECTIONS=10
+# 8-core starting point: four tasks, two files per task, four CPU-bound image jobs.
+DATABASE_MAX_CONNECTIONS=16
+WORKER_TASK_CONCURRENCY=4
 WORKER_CONCURRENCY=2
-IMAGE_PROCESSING_CONCURRENCY=2
+IMAGE_PROCESSING_CONCURRENCY=4
 
 # Resource ceilings tuned for an 8-core / 16 GB application host.
 POSTGRES_MEMORY_LIMIT=2g

docker/docker-compose.prod.yml

@@ -2,7 +2,7 @@ name: imageforge
 
 x-imageforge-environment: &imageforge-environment
   DATABASE_URL: postgres://imageforge:${POSTGRES_PASSWORD:?POSTGRES_PASSWORD is required}@postgres:5432/imageforge
-  DATABASE_MAX_CONNECTIONS: ${DATABASE_MAX_CONNECTIONS:-10}
+  DATABASE_MAX_CONNECTIONS: ${DATABASE_MAX_CONNECTIONS:-16}
   REDIS_URL: redis://redis:6379
   JWT_SECRET: ${JWT_SECRET:?JWT_SECRET is required}
   JWT_EXPIRY_HOURS: ${JWT_EXPIRY_HOURS:-168}
@@ -10,6 +10,7 @@ x-imageforge-environment: &imageforge-environment
   BILLING_PROVIDER: ${BILLING_PROVIDER:-stripe}
   STORAGE_PATH: /app/uploads
   PUBLIC_BASE_URL: ${PUBLIC_BASE_URL:-http://localhost:8080}
+  WORKER_TASK_CONCURRENCY: ${WORKER_TASK_CONCURRENCY:-4}
   WORKER_CONCURRENCY: ${WORKER_CONCURRENCY:-2}
   IMAGE_PROCESSING_CONCURRENCY: ${IMAGE_PROCESSING_CONCURRENCY:-2}
   ALLOW_ANONYMOUS_UPLOAD: ${ALLOW_ANONYMOUS_UPLOAD:-true}