Briefly, this error occurs when Elasticsearch tries to allocate a dangled index but fails. A dangled index is an index that exists on a node but is not part of the cluster state. This can happen due to network issues, node failures, or incorrect configurations. To resolve this issue, you can manually import the dangled index using the import dangling index API, ensure that the network is stable and nodes are properly configured, or delete the dangled index if it’s not needed.
This guide will help you check for common problems that cause the log ” failed to send allocate dangled ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: dangled.
Log Context
Log “failed to send allocate dangled” classname is DanglingIndicesState.java.
We extracted the following from Elasticsearch source code for those seeking an in-depth context :
logger.info("failed to send allocated dangled"; e);
}
}
);
} catch (Exception e) {
logger.warn("failed to send allocate dangled"; e);
}
}
@Override
public void clusterChanged(ClusterChangedEvent event) {
