For internal communication between CoreMedia CMCC components, gRPC has been added as an alternative to CORBA. Communication via CORBA is still available and the default. As long as you plan to stick with CORBA, no changes to your code or operations procedures are required. Should you want to switch to gRPC as your communications protocol between CMCC components, the following sections will provide information and pointer for additional details to do so.

In the course of adding gRPC as a communications protocol, however, breaking changes were introduced:

Upgrade Information

With release 2512.0 of the CoreMedia system, the Workflow Server does not yet offer gRPC services to its clients. Activating gRPC on clients (e.g., Studio Server or command line tools) won't do any harm as long as these are of release 2512.0, too. Future clients, though, will fail to connect to that Workflow Server if gRPC is active on them.

Keep this in mind when operating a mixed-release CoreMedia system setup. In such scenarios (e.g., during upgrades), it is recommended to leave clients in their default protocol mode which is CORBA.

While servers always offer both protocols for clients to connect, clients can be configured to use either gRPC or CORBA. The protocol can be chosen freely on each start of a component. Currently, CORBA is the default protocol.

Note that Content Servers and the Workflow Server also contain client parts for internal communication, e.g., for internal repository access, publication, replication, etc. Choosing a protocol on a server therefore does make a difference although services offered by the servers to their clients always cover both protocols.

Information for Developers

See Blueprint Developer Manual, sections 3.2.2 Docker Compose Setup / Docker Compose Configuration and 4.3 Build and Run the Applications / Internal Communication Protocol on how to activate gRPC in a development setup. Refer to Unified API Developer Manual, section 4.1.1 Creating a Connection for details on connection parameters for gRPC.

Information for Operations Engineers

See Operations Basics, section 4.4 Communication between the System Applications for details on how to configure and secure gRPC communication in your environment.

Replicator and Publisher require specific configuration for gRPC.

For the Publisher, refer to Deployment Manual, section 3.2.3 Properties for the Publisher.

For the Replicator, refer to Deployment Manual, section 3.2.5 Properties for Replicator Configuration.

In a Nutshell

Adjust hostnames and ports in the following variables to your setup where necessary. Mind that there is no scheme to the gRPC addresses as those are not URIs.

To enable gRPC communication for a client or the Workflow Server, set the following environment variables on the respective process (command line tool, local start via Maven, Docker container, etc):

To enable gRPC communication for the Content Management Server, set the following environment variables on the Content Management Server process:

To enable gRPC communication for a Replication Live Server, set the following environment variables on the Replication Live Server process:

To enable gRPC communication for a Master Live Server, just set

To enable gRPC communication for command line tool publishall, see new command line options in Content Server Manual, section 3.13.3.5 Publishall .

(CMS-28689)