Reindex time series indexes and keep original creation date for retention

OpenSearch
1

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Describe the issue:

Hey everyone,

I need to reindex some time-series indexes, and I want the new indexes to keep the same creation date as the old ones. My retention is based on the actual index creation date, so when I reindex, the new index gets a new creation date and the retention doesn’t work correctly anymore.

How can I keep the retention behavior after reindexing?
Is there a way to preserve the original creation date on the new index?
Maybe there is another option to use a custom field or some other configuration to keep the retention logic, without creating a new ISM policy?

Thanks!

2

@YossiCohen The reindex operation always creates a fresh creation_date, there is no API available to change this behaviour.

What is the reason for the indexing? Could you maybe use _update_by_query instead, keeping the original creation date?

If reindexing is indeed necessary you would either have to create a new ISM policy for the new index, or manually delete them when necessary.

3

This is clearly an important and often asked for feature. It should be possible to modify the creation_date of indices, or at least to create ISM policies based on queries, e.g. min/max document age