Metadata Indexing


OpenIO SDS can be configured to index all objects metadata in an external ElasticSearch.

  • All object metadata are accessible for search requests using ElasticSearch API.
  • Metadata search allow retrieving objects matching certain criteria (for example: search PNG images less than 2MB created last month).
  • Custom user metadata are also supported.


Indexing of object metadata is performed via a grid function indexing. On OpenIO SDS, all actions on objects invoke the indexing function which manage an elasticsearch index.

The oio-event-agent component, responsible for processing events is configured to invoke, via the webhook filter, the indexing function. During the invocation, the webhook filter is responsible for formatting and retrieving all the information needed to index the metadata of the object.

Here are the default SDS metadata automatically indexed:

  • account account name
  • user user name
  • path object name
  • ns namespace name
  • hash object hash
  • mime-type object mime-type
  • size object size integer
  • version object version integer
  • ctime object creation time unix timestamp
  • mtime object modification time unix timestamp
  • id object id
  • chunk-method object chunk method
  • policy object storage policy
  • deleted object deleted flag integer


  • one sds account = one elasticsearch index
  • Objects metadata also include user metadata
  • A default mapping is specified globally for the namespace, value can be overriden by account