Running Sulu in a Multi-Server Setup

Sulu is built with horizontal scaling in mind and allows to distribute the load of your application between multiple servers. In such a setup, it is important to configure your application to use centralized solutions for session management, cache management, search indexes and media storage.

Media Storage

Media files that are uploaded in the media section of the Sulu administration interface are stored in the filesystem of the current server by default. If your application runs on multiple servers, you need to configure an external storage adapter for your media files.

# config/packages/sulu_media.yaml
    storage: s3
            key: 'your aws s3 key'
            secret: 'your aws s3 secret'
            bucket_name: 'your aws s3 bucket name'
            path_prefix: 'optional path prefix'
            region: 'eu-west-1'

HTTP Cache

Sulu utilizes the FOSHttpCacheBundle to improve response times by caching rendered pages. This cache is automatically invalidated when the content of a page is changed. To prevent different cache entries on different servers, you need to configure Varnish as a centralized caching proxy.

# config/packages/sulu_http_cache.yaml
            enabled: false
            enabled: true
            servers: [ '' ]

Application Cache

The Symfony cache improves the speed of your application by caching metadata, doctrine results and PHPCR data. If your application runs on multiple servers, you need to configure a centralized caching adapter like redis for your app cache. Additionally, if the application runs in different directories on different servers, you need to set a static prefix_seed:

# config/packages/cache.yaml
        app: cache.adapter.redis
        default_redis_provider: 'redis://'

        # Set "prefix_seed" to use same cache namespace independent of project location:
        prefix_seed: your_vendor_name/app_name

Search Index

Sulu uses the MassiveSearchBundle for its search functionality on the website and in the administration interface. By default the bundle creates an optimized search index in the filesystem of the current server. To prevent outdated search results, you need to configure Elasticsearch as a centralized search adapter.

# config/packages/massive_search.yaml
    adapter: elastic
            version: 7.13
            hosts: [ '' ]

Session Management

By default, Symfony stores active sessions in the filesystem of the current server. To prevent random logouts between requests, you need to manage your sessions in a centralized storage that is accessed by all your servers. Have a look at the Store Sessions in a Database section of the Symfony documentation to find out how to store sessions in a database like Redis or MySQL. Alternatively, you can set a centralized session.save_handler directly in your php.ini:

session.save_handler = redis
session.save_path = "tcp://"