Connection already closed – How to solve this Elasticsearch exception

Opster Team

August-23, Version: 6.8-8.9

Briefly, this error occurs when Elasticsearch tries to use a network connection that has already been closed. This could be due to network issues, a timeout, or the node being shut down. To resolve this issue, you can try to increase the timeout settings, ensure the network connection is stable, or check if the node is running properly. If the problem persists, consider checking the Elasticsearch logs for more detailed information about the error.

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” class name is We extracted the following from Elasticsearch source code for those seeking an in-depth context :

 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;