Failed to resolve host - Common causes and quick fixes

Failed to resolve host – How to solve this Elasticsearch exception

Opster Team

August-23, Version: 6.8-8.9

Briefly, this error occurs when Elasticsearch is unable to resolve the hostname specified in its configuration. This could be due to a typo in the hostname, network issues, or DNS resolution problems. To resolve this issue, you can check the hostname for typos, verify your network connection, or check your DNS settings. If the problem persists, you may need to consult with your network administrator or use an IP address instead of a hostname.

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

Log Context

Log “Failed to resolve host” class name is TcpTransport.java. We extracted the following from Elasticsearch source code for those seeking an in-depth context :

 InetAddress[] hostAddresses;
 List profileBindHosts = profileSettings.bindHosts;
 try {
 hostAddresses = networkService.resolveBindHostAddresses(profileBindHosts.toArray(Strings.EMPTY_ARRAY));
 } catch (IOException e) {
 throw new BindTransportException("Failed to resolve host " + profileBindHosts; e);
 }
 if (logger.isDebugEnabled()) {
 String[] addresses = new String[hostAddresses.length];
 for (int i = 0; i < hostAddresses.length; i++) {
 addresses[i] = NetworkAddress.format(hostAddresses[i]);