Ports Usage

Dgraph cluster nodes use a range of ports to communicate over gRPC and HTTP. Choose these ports carefully based on your topology and mode of deployment, as this will impact the access security rules or firewall configurations required for each port.

Types of ports

Dgraph Alpha and Dgraph Zero nodes use a variety of gRPC and HTTP ports, as follows:

• gRPC-internal-private: Used between the cluster nodes for internal communication and message exchange. Communication using these ports is TLS-encrypted.
• gRPC-external-private: Used by Dgraph Live Loader and Dgraph Bulk loader to access APIs over gRPC.
• gRPC-external-public: Used by Dgraph clients to access APIs in a session that can persist after a query.
• HTTP-external-private: Used for monitoring and administrative tasks.
• HTTP-external-public: Used by clients to access APIs over HTTP.

Default ports used by different nodes

Dgraph Node Type	gRPC-internal-private	gRPC-external-private	gRPC-external-public	HTTP-external-private	HTTP-external-public
zero	50801	50801		60802
alpha	7080		9080		8080
ratel					8000

¹: Dgraph Zero uses port 5080 for internal communication within the cluster, and to support the data import tools: Dgraph Live Loader and Dgraph Bulk Loader.

²: Dgraph Zero uses port 6080 for administrative operations. Dgraph clients cannot access this port.

Users must modify security rules or open firewall ports depending upon their underlying network to allow communication between cluster nodes, between the Dgraph instances, and between Dgraph clients. In general, you should configure the gRPC and HTTP external-public ports for open access by Dgraph clients, and configure the gRPC-internal ports for open access by the cluster nodes.

Ratel UI accesses Dgraph Alpha on the HTTP-external-public port (which defaults to localhost:8080) and can be configured to talk to a remote Dgraph cluster. This way you can run Ratel on your local machine and point to a remote cluster. But, if you are deploying Ratel along with Dgraph cluster, then you may have to expose port 8000 to the public.

Port Offset To make it easier for users to set up a cluster, Dgraph has default values for the ports used by Dgraph nodes. To support multiple nodes running on a single machine or VM, you can set a node to use different ports using an offset (using the command option --port_offset). This command increments the actual ports used by the node by the offset value provided. You can also use port offsets when starting multiple Dgraph Zero nodes in a development environment.

For example, when a user runs Dgraph Alpha with the --port_offset 2 setting, then the Alpha node binds to port 7082 (gRPC-internal-private), 8082 (HTTP-external-public) and 9082 (gRPC-external-public), respectively.

Ratel UI by default listens on port 8000. You can use the -port flag to configure it to listen on any other port.