Low concurrent rebalance
Cluster concurrent rebalance is below the recommended value. Shard moves proceed slowly when disks are uneven.
For a complete list of insights, refer to AutoOps insights.
| Field | Value |
|---|---|
| Component | Elasticsearch |
| Severity | Medium |
| Scope | Cluster |
| Domains | performance, configuration, shard-allocation |
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 |
|---|---|---|
| Minimum cluster concurrent rebalance | Integer | 2 |
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.
cluster.routing.allocation.cluster_concurrent_rebalance is 12. Recommended minimum: 2.
AutoOps shows different recommendations depending on how their conditions match your deployment or cluster.
Increase concurrent rebalance limit
Condition: Always shown for this insight.
cluster.routing.allocation.cluster_concurrent_rebalance controls how many shards rebalance at once. Raise it with the action below to finish rebalancing sooner.
PUT _cluster/settings
{
"persistent": {
"cluster.routing.allocation.cluster_concurrent_rebalance": 2
}
}
Requires the manage cluster privilege. Requires Elasticsearch 8.0.0 or later. This action changes cluster or index configuration.
This setting caps how many shards the cluster can move at once to rebalance shard distribution across nodes, while respecting allocation filters and forced awareness.
If the value is too low, the cluster cannot move shards quickly off a nearly full disk to nodes with more space. Disks might keep filling until flood stage, when indices become read-only. Some nodes might be cannot allocate shards, which can turn the cluster yellow or red and block writes to affected indices.