Can t connect to a null node – How to solve this Elasticsearch exception

Opster Team

August-23, Version: 6.8-8.9

Briefly, this error occurs when Elasticsearch tries to connect to a node that is either not defined or has a null value. This could be due to incorrect configuration settings or network issues. To resolve this, ensure that the node is correctly defined in the configuration file and that the network connection is stable. Also, check if the node is up and running. If the problem persists, consider restarting the Elasticsearch cluster or the specific node that is causing the issue.

This guide will help you check for common problems that cause the log ” can’t connect to a null node ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: node.

Log Context

Log “can’t connect to a null node” class name is We extracted the following from Elasticsearch source code for those seeking an in-depth context :

 ActionListener listener
 ) throws ConnectTransportException {  ConnectionProfile resolvedProfile = ConnectionProfile.resolveConnectionProfile(connectionProfile; defaultProfile);
 if (node == null) {
 listener.onFailure(new ConnectTransportException(null; "can't connect to a null node"));
 }  if (acquireConnectingRef() == false) {
 listener.onFailure(new ConnectTransportException(node; "connection manager is closed"));