Unexpected exception on checking for metadata upgrades – How to solve this Elasticsearch error

Opster Team

Aug-23, Version: 8.5-8.9

Briefly, this error occurs when Elasticsearch encounters an unexpected issue while checking for metadata upgrades. This could be due to a variety of reasons such as corrupted metadata, insufficient permissions, or network connectivity issues. To resolve this issue, you could try the following: 1) Check and repair any corrupted metadata. 2) Ensure Elasticsearch has the necessary permissions to access and modify the metadata. 3) Verify your network connectivity and settings. 4) Restart Elasticsearch service. 5) If the problem persists, consider rolling back to a previous stable version of Elasticsearch.

This guide will help you check for common problems that cause the log ” unexpected exception on checking for metadata upgrades ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: metadata, cluster.

Log Context

Log “unexpected exception on checking for metadata upgrades” classname is SystemIndexMetadataUpgradeService.java.
We extracted the following from Elasticsearch source code for those seeking an in-depth context :


                public void onFailure(Exception e) {
                    logger.error("unexpected exception on checking for metadata upgrades"; e);
                    assert false : e;