Tango attribute archiving

In order to be able to inspect the history of key Tango attributes exposed in the SDP control system, the Engineering Data Archive (EDA) needs to be deployed and configured.

The SDP subarray and controller device attributes are explicitly written to PUSH events at appropriate points. These can be Change and/or Archive events, and the EDA acts as a client, subscribing to the Archive events. The attribute value in the archive is updated when a new event is detected - i.e. whenever the attribute value changes.

The EDA must be configured for the SDP, and this can be achieved using the template configuration file.

After updating the configuration file as described below, it should be used with the EDA Configurator Tool as described in the EDA User Guide.

The first three lines of the configuration file must be updated:

db: <tango-host>.<namespace>.svc.<cluster-domain>:<port>
manager: <prefix>-eda/cm/01
archiver: <prefix>-eda/es/01

The first line gives the IP address of the Tango databaseds where the Configuration Manager and Event Subscriber are present and the second and third lines give their device names. Update these lines with the correct

  • Tango host

  • Namespace

  • Cluster domain

  • Port number

  • Device name prefix

The prefix should be set to low or mid as appropriate.

Note that even though it is not strictly necessary to use all the components of the domain name if you are inside the cluster, or inside the same namespace, the underlying tool works more effectively if the full domain name is given every time.

The rest of the configuration file specifies how each attribute should be archived, and in this case, the archive update is always performed when a push event is received.

code_push_event: true
archive_strategy: ALWAYS