Index Finished How could I know? any mechanism available?

Elastic Stack Elasticsearch
1

suppose I have indexed some data, but client call for data, in the meantime ES does not finish the data indexes. how can i know the data is not index yet in ES?

2

Are you GETting the document, or just searching?

3

That means,From server side i have call for document write operation, but ES doesn't completed document index yet. In the meantime client side call Get() api from ES, but ES still no data exist, because index is not finished yet.

So i need to know when index finished in ES.

Thank you.