High deleted-docs ratio
Some indices retain a large share of documents marked deleted but not yet merged away. Those tombstones still use disk and add work during searches.
For a complete list of insights, refer to AutoOps insights.
| Field | Value |
|---|---|
| Component | Elasticsearch |
| Severity | Low |
| Scope | Index |
| Domains | disk-storage, index-management |
The following is an example of what you might see when this insight is triggered. Real insights use live data and links from your deployment or cluster.
Some indices retain a high ratio of deleted documents that still occupy disk.
Highest ratio: logs-prod-000045 (500 GB, 42,000,000 total docs, 85% deleted).
AutoOps shows different recommendations depending on how their conditions match your deployment or cluster.
Force merge deleted documents
Condition: Always shown for this insight.
Run a force merge with only_expunge_deletes=true on logs-prod-000045, logs-prod-000046 to reclaim disk used by deleted documents. Use the action below.
POST logs-archive-000001/_forcemerge?only_expunge_deletes=true
Requires the manage cluster privilege. Requires Elasticsearch 8.0.0 or later. This action changes cluster or index configuration.
Reindex indices
Condition: Always shown for this insight.
Reindex indices with many deleted documents into new indices. After reindex completes, delete the old indices to reclaim disk space.
When you delete or update documents, Elasticsearch marks old versions as deleted rather than removing them immediately. Over time, a high deleted-docs ratio means much of the index size is tombstones. That wastes disk and can slow searches because more segments must be filtered.