Elasticsearch version 8.6.1edit

Also see Breaking changes in 8.6.

Known issuesedit

  • Shard rebalancing may temporarily unbalance cluster

    From 8.6.0 onwards the default shard rebalancing algorithm will compute the final desired balance and then make shard movements to reconcile the current state of the cluster with the desired state. However the order in which the shard movements take place may be skewed towards certain nodes, causing the cluster to become temporarily unbalanced while the reconciliation is ongoing. As always, once a node reaches a disk watermark it will not accept any additional shards, but this skew may result in nodes reaching their disk watermarks more often than expected in normal operation. Once the reconciliation process completes, the cluster will be balanced again.

    To avoid this problem, upgrade to 8.8.0 or later.

  • When the ingest attachment processor is used, the interaction of Tika with log4j 2.18.0 and higher (introduced in Elasticsearch 8.4.0) results in excessive logging. This logging is so excessive that it can lead to cluster instability, to the point where the cluster is unusable and nodes must be restarted. (issue: #91964). This issue is fixed in Elasticsearch 8.7.0 (#93878)

    To resolve the issue, upgrade to 8.7.0 or higher.

Bug fixesedit

Data streams
  • Fix wildcard expansion for delete-by-query on data streams #92891
  • Fix wildcard expansion for update-by-query on data streams #92717 (issue: #90272)
  • Patch jackson-core with locally modified class #92984 This fixes an issue in jackson parsing (issue: #92480)
  • Fix ByteArrayIndexInput with nonzero offset #93205
  • Get repository metadata from the cluster state doesn’t throw an exception if a repo is missing #92914
  • Don’t announce ready until file settings are applied #92856 (issue: #92812)
Machine Learning
  • Utilise parallel allocations where the inference request contains multiple documents #92359
  • Fix _bulk api dynamic_templates and explicit op_type #92687
  • Avoid doing I/O when fetching min and max for keyword fields #92026
  • Reduce memory required for search responses when many shards are unavailable #91365 (issue: #90622)