Io error while building empty agg – How to solve this Elasticsearch exception

Opster Team

August-23, Version: 7.13-8.9

Briefly, this error occurs when Elasticsearch encounters an Input/Output issue while building an empty aggregation. This could be due to insufficient disk space, incorrect file permissions, or a network connectivity issue. To resolve this, you can free up disk space, check and correct file permissions, or troubleshoot network connectivity. Additionally, ensure that your Elasticsearch version is up-to-date and compatible with your system configuration.

This guide will help you check for common problems that cause the log ” io error while building empty agg ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: search, aggregations.

Log Context

Log “io error while building empty agg” class name is We extracted the following from Elasticsearch source code for those seeking an in-depth context :

 public final InternalAggregation buildEmptyAggregation() {
 try {
 return adapt(delegate.buildEmptyAggregation());
 } catch (IOException e) {
 // We don't expect this to happen; but computers are funny.
 throw new AggregationExecutionException("io error while building empty agg"; e);
 }  @Override
 public final Aggregator[] subAggregators() {