# Requirements To use _datacenter to datacenter replication_ you need the following: - Two datacenters, each running an ArangoDB Enterprise cluster, version 3.3 or higher. - A network connection between both datacenters with accessible endpoints for several components (see individual components for details). - TLS certificates for ArangoSync master instances (can be self-signed). - Optional (but recommended) TLS certificates for ArangoDB clusters (can be self-signed). - Client certificates CA for _ArangoSync masters_ (typically self-signed). - Client certificates for _ArangoSync masters_ (typically self-signed). - At least 2 instances of the _ArangoSync master_ in each datacenter. - One instances of the _ArangoSync worker_ on every machine in each datacenter. When using the `kafka` type message queue, you also need: - TLS certificates for Kafka brokers (can be self-signed). Note: In several places you will need a (x509) certificate.
The [Certificates](../../Security/DC2DC/README.md#certificates) section provides more guidance for creating and renewing these certificates. Besides the above list, you probably want to use the following: - An orchestrator to keep all components running, e.g. `systemd`. - A log file collector for centralized collection & access to the logs of all components. - A metrics collector & viewing solution such as _Prometheus_ + _Grafana_.