Cold Storage: Document index initialization on coldstorage:beingRetrieved property

On a huge repository, we can see:

Invalid command produces an empty document set

, and you can see the NXQL query

SELECT * FROM Document, Relation WHERE ecm:mixinType = 'ColdStorage' AND coldstorage:beingRetrieved = 1

In the stack trace you can see the mongodb version of the query and the reason of the failure:

Query timed out on client side after socketTimeout exceeded

As a matter of fact, the Cold Storage addon scans the repository to check the documents on which a retrieve has been requested. This scan is scheduled every hour:

• https://github.com/nuxeo/nuxeo-coldstorage/blob/lts-2021/nuxeo-coldstorage/src/main/resources/OSGI-INF/coldstorage-events-contrib.xml#L6
• https://github.com/nuxeo/nuxeo-coldstorage/blob/lts-2021/nuxeo-coldstorage-package/src/main/resources/install/templates/coldstorage/nuxeo.defaults#L7

and performs a query like

SELECT * FROM Document, Relation WHERE ecm:mixinType = 'ColdStorage' AND coldstorage:beingRetrieved = 1

We added an index for 2021, https://github.com/nuxeo/nuxeo-coldstorage/blob/lts-2021/nuxeo-coldstorage/src/main/resources/OSGI-INF/coldstorage-core-types-contrib.xml as per NXP-29261 but this is not available for 10.10.

We should add recommendations in the README to manually create such an index in 10.10.