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Comment by manigandham | Hacker News Reader

Elasticsearch has a "refresh" query flag to force immediate consistency: https://www.elastic.co/guide/en/elasticsearch/reference/curr...

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That still doesn't guarantee that a consecutive read is gonna get the last state. Welcome to the wonderful world of "eventual consistency".

How so? That's the entire point of the feature. What else is there to update?

It guarantees that all replications will report state in sync with each other on search, not that the last reported state is the actual current state of the index.

As the numerous comments here and the documentation states, the refresh flag on your insert/update will ensure that changed data in that request is consistent for queries after.

Where did you get the behavior you described? Are you sure you're not confusing this for the separate refresh command itself? That is not attached to any particular insert/update.

The "refresh=wait_for" [1] index setting does guarantee that a subsequent read will get the data. It causes all shards to refresh:

    Refresh the relevant primary and replica shards
    (not the whole index) immediately after the operation
    occurs, so that the updated document appears in search
    results immediately

There's also the "wait_for_active_shards=<n>" setting, which merely asks to wait until n shards have written the changes.

[1] https://www.elastic.co/guide/en/elasticsearch/reference/curr...

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