Rejected indexing
One or more nodes are rejecting indexing requests. Clients might lose data if they do not retry successfully.
For a complete list of insights, refer to AutoOps insights.
| Field | Value |
|---|---|
| Component | Elasticsearch |
| Severity | High |
| Scope | Node |
| Domains | performance, indexing, stability |
You can customize these settings to adjust when AutoOps detects this event and presents the insight. Refer to AutoOps event settings for details.
The default customization settings are:
| Setting | Type | Default |
|---|---|---|
| Rejected indexing count threshold | Integer | 1 |
| Consecutive samples above threshold | Integer | 1 |
Raising these thresholds reduces noise but delays detection. Lowering them triggers the insight sooner but can increase alerts during minor blips.
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.
Indexing requests are being rejected on es-data-01 and es-data-02.
- Indices with high indexing activity:
logs-prod-000045
AutoOps shows different recommendations depending on how their conditions match your deployment or cluster.
Rollover indices
Condition: Shown when high-indexing activity is detected and if index has less primary shards than available data nodes.
If logs-prod-000045 are time-based, roll them over and set 1 primary shards on the new write index so you can avoid a heavy segment merge on the current indices.
Rollover indices by shard size
Condition: Shown when high-indexing activity is detected and if primary shard size > 30GB.
If logs-prod-000045 are time-based, roll them over when average shard size reaches your target.
Review index templates and mappings
Condition: Shown when high-indexing activity is detected and for indexes with highest indexing latency.
Review templates and mappings for logs-prod-000045; they strongly affect indexing performance. Fix oversized mappings, unnecessary fields, and inefficient index settings.
Review indexing slow logs
Condition: Shown when indexing rejections occur on the node.
Enable indexing slow logs with the action below on logs-prod-000045, then review the logs to find slow index operations. On Elasticsearch 8.14+, set index.indexing.slowlog.include.user to true to record which user triggered a slow operation.
PUT logs-prod-000045/_settings
{
"index.indexing.slowlog.threshold.index.warn": "10s",
"index.indexing.slowlog.threshold.index.info": "5s",
"index.indexing.slowlog.threshold.index.debug": "2s",
"index.indexing.slowlog.threshold.index.trace": "500ms",
"index.indexing.slowlog.source": "1000"
}
Requires the manage index privilege. Requires Elasticsearch 8.0.0 or later. This action changes cluster or index configuration.
Add data node
Condition: Shown when high-indexing activity is detected and if index has more primary shards as available data nodes.
Add a data node to increase capacity and reduce pressure on the existing nodes.
Review indexing slow logs
Condition: Always shown for this insight.
Check indexing slow logs on es-data-01 to find expensive indexing operations and address the root cause.
When Elasticsearch rejects indexing requests, writes fail at the client. Without successful retries, data can lag or be lost.
Rejections often follow sustained ingest pressure: a full or backed-up write thread pool, documents that do not match the index mapping, indices put into read-only mode at the flood-stage disk watermark, or circuit breakers that trip while processing bulks.
If rejections continue, ingest stays unreliable until pressure drops, mappings and disk pressure are fixed, or capacity increases.