gc - cache false

[antje-s]

8.1.4. 4. Cache False Directive/Steps

I am not sure if we may have a problem with the metadata workflow:

a) origin-metadata centre --> pub message with cache false under origin-topic
b) GCs re-publish the message under the cache topic
(Problem: the WIS2 Node centres will already download this message with download link to origin metadata even if we take cache=true, original metadata file would be on the cache)
c) GDCs update the metadata and publish it as an update under origin with cache true
d) GCs cache update metadata and publish it under cache
e) WIS2 Nodes receive cache message for updated metadata and download updated metadata from the cache

Perhaps we could use recommended and core as a workaround:

a) origin-metadata centre --> pub message with cache false under origin-topic recommended (origin/a/wis2/+/metadata/recommened/#)
b) nothing to do for GCs (but GDCs should be subscribed under origin-recommened topic
c) GDCs update the metadata and publish it under origin-topic core with cache true
d) GCs cache download metadata from GDCs and publish it under cache
e) WIS2 Nodes receive cache message for metadata and download (only updated) metadata from the cache

The centres also could restrict access to the GDCs so that the intermediate link does not work for all WIS2 Nodes. But I don't think that's a good solution, as we then plan for download errors.
Or am I missing something? That could also well be...