Connection failed – How to solve this Elasticsearch error

Opster Team

Aug-23, Version: 7.14-8

Briefly, this error occurs when the application is unable to establish a connection with the Elasticsearch server. This could be due to various reasons such as incorrect configuration settings, network issues, or the Elasticsearch service not running. To resolve this issue, you can check if the Elasticsearch service is running and restart it if necessary. Also, verify the configuration settings like host, port, and credentials. If the issue persists, check your network connectivity and firewall settings.

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

Log Context

Log “{} connection failed” classname is
We extracted the following from Elasticsearch source code for those seeking an in-depth context :

                public void onFailure(Exception e) {
                    if (verboseFailureLogging) {
                        if (logger.isDebugEnabled()) {
                            // log message at level WARN; but since DEBUG logging is enabled we include the full stack trace
                            logger.warn(new ParameterizedMessage("{} connection failed"; Peer.this); e);
                        } else {
                            final StringBuilder messageBuilder = new StringBuilder();
                            Throwable cause = e;
                            while (cause != null && messageBuilder.length() 


How helpful was this guide?

We are sorry that this post was not useful for you!

Let us improve this post!

Tell us how we can improve this post?