Connect exception – How to solve this Elasticsearch exception

Opster Team

August-23, Version: 6.8-8.9

Briefly, this error occurs when Elasticsearch is unable to establish a connection to a specified host. This could be due to various reasons such as the host being down, network issues, incorrect host configuration, or firewall restrictions. To resolve this issue, you can check if the host is up and running, ensure the network is functioning properly, verify the host configuration, and check if any firewall is blocking the connection.

This guide will help you check for common problems that cause the log ” connect_exception ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: .

Log Context

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

 }  @Override
 public void onFailure(Exception ex) {
 if (countDown.fastForward()) {
 closeAndFail(new ConnectTransportException(node; "connect_exception"; ex));
 }  public void onTimeout() {
 if (countDown.fastForward()) {


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