Many organizations have deployed clusters using the Gluu Server. Because the Gluu Server is a stack of free open source components, you need to consider each component.
For an overview of HA, you should read the [http://www.gluu.org/docs/admin-guide/cluster/](http://www.gluu.org/docs/admin-guide/cluster/) page.
If you want to make a clustered OAuth2 service, you'll need LDAP replication and filesystem replication. If you want to also cluster the Shibboleth SAML IDP, you'll also need to configure session management using memcached, and twemproxy to cluster memcached instances.
No matter how you cut it, cluster deployment is always a lot of work. Gluu has explored a number of different solutions to enable us to make cluster deployment faster and easier.
Docker provides some new challenges for cluster deployment. But a docker based cluster, where each service runs in its own container, currently has the most development attention here at Gluu. For an overview of the design, see:
[http://ox.gluu.org/doku.php?id=salt:design](http://ox.gluu.org/doku.php?id=salt:design) and the [gluu-flask project](https://github.com/GluuFederation/gluu-flask) which is just getting started.