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 ” connection already closed ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: .
Log Context
Log “connection already closed”classname is TcpTransport.java We extracted the following from Elasticsearch source code for those seeking an in-depth context :
@Override
public void sendRequest(long requestId; String action; TransportRequest request; TransportRequestOptions options)
throws IOException; TransportException {
if (isClosing.get()) {
throw new NodeNotConnectedException(node; "connection already closed");
}
TcpChannel channel = channel(options.type());
// In this is a proxy request; determine whether we want to compress based on the wrapped request
final TransportRequest wrapped;
Find & fix Elasticsearch problems
