Exception while closing channels – How to solve related issues

Opster Team

Feb-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.

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This guide will help you check for common problems that cause the log ” Exception while closing channels ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: handler.

Log Context

Log “exception while closing channels” classname is AbstractHttpServerTransport.java.
We extracted the following from Elasticsearch source code for those seeking an in-depth context :

         synchronized (httpServerChannels) {
            if (httpServerChannels.isEmpty() == false) {
                try {
                    CloseableChannel.closeChannels(new ArrayList(httpServerChannels); true);
                } catch (Exception e) {
                    logger.warn("exception while closing channels"; e);
                } finally {


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