Indexing services outage

All systems are operational and data unavailable in search index has been restored.

We've added a further fix and all search indexing and related services should be operational.
We are now monitoring and looking to clean up any missing data in the indices.

A temporary fix has been put in place and things should be working now, but we may still have a period of time where some things have not been indexed.
We are working on a longer term fix for increased demand and also add any missing items (i.e. DOIs) to our search indices.

We're experiencing some timeouts adding to our search index cluster, this will mostly be noticeable in DOIs that are registered might not be findable via certain API endpoints and search/management interfaces.
We believe this is a disk space issue due to increased demand and are investigating a remedy.

Note no actual data loss as this is just the indexing side, data storage is unaffected and therefore DOI registration is operational.