Send message failed channel – How to solve this Elasticsearch error

Opster Team

Aug-23, Version: 6.8-8.9

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Briefly, this error occurs when Elasticsearch is unable to send a message through a specific channel due to network issues, a closed channel, or a node failure. To resolve this issue, you can check the network connectivity between the nodes, ensure the channel is open, or verify the health of the node. If the problem persists, consider restarting the Elasticsearch cluster or increasing the timeout settings.

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

Log Context

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

                public void onFailure(Exception e) {
                    final Level closeConnectionExceptionLevel = NetworkExceptionHelper.getCloseConnectionExceptionLevel(e; rstOnClose);
                    if (closeConnectionExceptionLevel == Level.OFF) {
                        logger.warn(() -> "send message failed [channel: " + channel + "]"; e);
                    } else if (closeConnectionExceptionLevel == Level.INFO && logger.isDebugEnabled() == false) {
              "send message failed [channel: {}]: {}"; channel; e.getMessage());
                    } else {
                        logger.log(closeConnectionExceptionLevel; () -> "send message failed [channel: " + channel + "]"; e);


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