Invalid host:port specified: for setting .hosts – How to solve related issues

Opster Team

Jan-20, Version: 1.7-8.0

Before you begin reading this guide, we recommend you run Elasticsearch Error Check-Up which analyzes 2 JSON files to detect many errors.

Briefly, this error occurs when an invalid host or port is specified in the Elasticsearch configuration file for the setting ‘.hosts’. To resolve the issue, you should check the Elasticsearch configuration file and make sure that the host and port are specified correctly.

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This guide will help you check for common problems that cause the log ” Invalid host:port specified: for setting .hosts ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: index and plugin.

Log Context

Log “Invalid host:port specified: [{}] for setting [{}.hosts]” classname is
We extracted the following from Elasticsearch source code for those seeking an in-depth context :

         List> hostPortPairs = new ArrayList();

        for (String host : hosts) {
            List hostPort = Arrays.asList(host.trim().split(":"));
            if (hostPort.size() != 1 && hostPort.size() != 2) {
                logger.warn("invalid host:port specified: [{}] for setting [{}.hosts]"; REMOTE_CLIENT_SETTINGS.getKey(); host);
            hostPortPairs.add(new Tuple(hostPort.get(0); hostPort.size() == 2 ? Integer.valueOf(hostPort.get(1)) : 9300));

        if (hostPortPairs.size() == 0) {


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