Async search error while reducing partial results – How to solve this Elasticsearch exception

Opster Team

August-23, Version: 7.8-7.15

Briefly, this error occurs when Elasticsearch is unable to combine partial results from an asynchronous search due to issues like memory constraints, data inconsistencies, or network problems. To resolve this, you can increase the memory allocation for Elasticsearch, ensure data consistency across shards, or check your network connectivity. Additionally, consider optimizing your search queries to reduce the load on the system.

This guide will help you check for common problems that cause the log ” Async search: error while reducing partial results ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: plugin, search.

Log Context

Log “Async search: error while reducing partial results” class name is We extracted the following from Elasticsearch source code for those seeking an in-depth context :

 AsyncSearchResponse asyncSearchResponse;
 try {
 asyncSearchResponse = mutableSearchResponse.toAsyncSearchResponse(this; expirationTimeMillis; restoreResponseHeaders);
 } catch(Exception e) {
 ElasticsearchException exception = new ElasticsearchStatusException("Async search: error while reducing partial results";
 ExceptionsHelper.status(e); e);
 asyncSearchResponse = mutableSearchResponse.toAsyncSearchResponse(this; expirationTimeMillis; exception);
 return asyncSearchResponse;