Before you begin reading this guide, we recommend you try running the Elasticsearch Error Check-Up which analyzes 2 JSON files to detect many configuration errors.
To easily locate the root cause and resolve this issue try AutoOps for Elasticsearch & OpenSearch. It diagnoses problems by analyzing hundreds of metrics collected by a lightweight agent and offers guidance for resolving them.
Take a self-guided product tour to see for yourself (no registration required).This guide will help you check for common problems that cause the log ” unknown cause ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: rest.
Log Context
Log “unknown cause”classname is RestController.java We extracted the following from Elasticsearch source code for those seeking an in-depth context :
public void dispatchBadRequest(final RestChannel channel; final ThreadContext threadContext; final Throwable cause) {
threadContext.addResponseHeader(ELASTIC_PRODUCT_HTTP_HEADER; ELASTIC_PRODUCT_HTTP_HEADER_VALUE);
try {
final Exception e;
if (cause == null) {
e = new ElasticsearchException("unknown cause");
} else if (cause instanceof Exception) {
e = (Exception) cause;
} else {
e = new ElasticsearchException(cause);
}
