Only one running instance per participant

For a specific sedex participant (a specific sedex ID), only one sedex-Client instance may be used (installed and running) at any time. It is not permitted to operate multiple installations of the sedex-Client for the same participant. Otherwise, problems such as lost messages, inconsistent message states or other serious malfunctions may occur.

sedex does currently not support multiple sedex-Clients per participant

The sedex-Client maintains its own internal database about the message flow of a participant.
This database must exist only once — otherwise message consistency cannot be guaranteed.

You must therefore ensure — both organizationally and technically — that at any point in time only one sedex-Client is installed and running for the same participant.

This requirement applies equally to OS-based installations as well as to container-based installations.

Particular attention is required in situations such as:

• Testing scenarios, where multiple environments might inadvertently connect with the same sedex participant ID.
• Migration activities, where an old and a new sedex-Client may overlap temporarily.
• Container orchestration platforms (Kubernetes, OpenShift, etc.), which by default may start more than one instance in parallel (e.g. during container startup, migration, rescheduling or rolling updates). See section Container Orchestration for details on how to configure container environments properly to avoid this problem.

In all these cases, running more than one sedex-Client for the same participant can lead to message loss, fragment errors, database inconsistencies or severe operational disruptions.