Client did not trust this servers certificate; closing connection – 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 message indicates that the client did not trust the server’s certificate and the connection was closed. The reason for this error could be a problem with the certificate being used by the Elasticsearch instance or a problem with the client configuration. To resolve the issue, the certificate should be checked for issues or the client configuration should be updated.

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This guide will help you check for common problems that cause the log ” Client did not trust this servers certificate; closing connection ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: client and plugin.

Log Context

Log “Client did not trust this server’s certificate; closing connection {}” classname is
We extracted the following from Elasticsearch source code for those seeking an in-depth context :

        } else if (SSLExceptionHelper.isReceivedCertificateUnknownException(e)) {
            if (logger.isTraceEnabled()) {
                logger.trace(new ParameterizedMessage("client did not trust server's certificate; closing connection {}"; channel); e);
            } else {
                logger.warn("client did not trust this server's certificate; closing connection {}"; channel);
        } else {
            super.onException(channel; e);


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