Java REST Client - Refresh API and Default Refresh Index

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1

Hello, everyone!

I have a question about using the Java REST Client - Refresh API or the default refresh behavior in an Elasticsearch index.

In a certain part of an application I'm maintaining, I have an implementation that calls refresh after each indexing operation using:

RefreshResponse refreshResponse = client. Indices().refresh(request, RequestOptions.DEFAULT);

Doc: (Refresh API | Java REST Client [7.17] | Elastic)

I need to make an adjustment here for performance reasons.

When reading the Elasticsearch documentation, I came across the following parameter:

refresh_interval

Doc: (Refresh an index | Elasticsearch API documentation).

As I understand it, if this parameter is not explicitly set, Elasticsearch will perform a refresh operation every second on indexes that have received any requests in the last 30 seconds.

My question is: Do the two approaches serve the same purpose? In other words, is one an explicit API call on demand and the other the default automatic mechanism? If they are equivalent, I could reconsider my indexing approach and rely on the default update behavior instead of manually calling the API each time.

Thanks in advance for any insight!

2

Hello and welcome!

Your understanding is correct: calling the refresh api will trigger a manual, synchronous refresh operation, meaning the call won't return until refreshing is complete, while the automatic refresh mechanism will refresh, by default, every 1 second.

Here's the documentation for index.refresh_interval which explains more in depth how it works, from the settings documentation:

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How often you want to refresh depends on the nature of the application, for example if you need to ingest a very large amount of data, and you need all data to be correctly indexed and made available for search before performing an operation, then performing a manual refresh at the end of the indexing is the best way to make sure that all of the records are available.