ES should be indexed without the downtime of the ZAC

[annashamray]

The possible solution is to use alises

The idea is:

1. create alias
2. app now uses alias
3. index is rebuilt into new index
4. alias now points to new index
5. then old index is deleted

[annashamray]

Adding aliases will reduce the downtime but not solve the issue when the old index would be used by the application why the ES is being reindexed. And these errors can be harder to detect than the lack of ES index now.

This user story is put on hold until the design is well-thought and developed