DAPE.work
Login Register

Too Many Buckets Exception

Severity: High
Elasticsearch Version: 7.17.0

Problem

Elasticsearch throws too_many_buckets_exception during large aggregations

Root Cause

Aggregation exceeds the maximum buckets limit set by the index or cluster settings

How to Detect

Symptoms

  • Query logs show too_many_buckets_exception errors
  • High CPU and memory usage during large aggregation queries
  • Slow query response times

Commands

GET /_cluster/settings?include_defaults
GET /<index>/_search?size=0&track_total_hits=false
GET /<index>/_search?size=0&explain=true

Remediation Steps

  1. Increase 'search.max_buckets' setting in elasticsearch.yml or dynamically via cluster update API
  2. Optimize aggregation queries by reducing the scope or using composite aggregations
  3. Implement pagination or size limits on aggregations
  4. Review and refine index mappings to reduce unnecessary fields

Prevention

  • Set appropriate 'search.max_buckets' limits based on workload
  • Design aggregations to avoid large bucket counts
  • Monitor bucket counts regularly and alert on high values
  • Use composite aggregations for large datasets

Production Example

curl -XPUT -H 'Content-Type: application/json' "localhost:9200/_cluster/settings" -d '{"persistent": {"search.max_buckets": 100000}}'
View all Elasticsearch errors