Feature #17349
Updated by Nico César almost 4 years ago
This specification is for the server side (client side of this will be on separate tickets,). The component railsapi (endpoint /arvados/v1/collections) and making sure that controller
Current behaviour for collections' "replicas_desired" is to accept a Number[1] or 'null'. This has to be changed the database has the correct field type and stores correctly
To complete Epic #16107 all components in Arvados should be able to send a number of storage tiers and their desired replication for each tier.
Valid values:
<pre>
replicas_desired=null (or omited from the request)
</pre>
|_. Request Values |_. defaultCollectionReplication |_. Effective Value |_. Notes |
| replicas_desired=null (or omited from the request) | 3 | {"default": 3} | current behaviour |
| replicas_desired=null (or omited from the request) | | {"default": 2} | current behaviour see [2] |
| replicas_desired=42 | 2| {"default": 42} | |
| replicas_desired={"default": 34} | 2 | {"default": 34} | |
| replicas_desired={"archival": 1} | 2 | {"default": 1, "archival": 1} | To be talked in next grooming session. |
| replicas_desired={"default": 1 "archival": 1} | 2 | {"default": 1, "archival": 1} | |
| replicas_desired={"archival": 2} | 2 | {"default": 0, "archival": 2} | To be talked in next grooming session. |
This are values that should be rejected (To be talked in next grooming session)
|_. Invalid values |_. Notes |
| replicas_desired="42" | strings should not be allowed |
| replicas_desired={"default": "34"} | strings should not be allowed |
| replicas_desired={"archival": -1} | negative numbers should not be allowed|
| replicas_desired={} | empty |
The "Effective value" has to be stored in the database and when the collection is queried, should be return as a JSON object.
To be talked in next grooming session:
* What should we do when returning current values ? should we return replicas_desired=42 or replicas_desired={"default":42} ?
* How will backward compatibility works here?
* if the current effective value is {"default": 1, "archival": 1}, how old client will react?
[1] https://doc.arvados.org/v2.1/api/methods/collections.html
[2] https://doc.arvados.org/v2.0/sdk/python/arvados/arvados.collection-pysrc.html#Collection._my_block_manager