Send message failed channel channel – How to solve this Elasticsearch error

Opster Team

Aug-23, Version: 8.3-8.9

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, you can check the network connectivity between nodes, ensure the channel is open, or verify the health of the node. If the issue persists, consider increasing the timeout settings or checking the cluster’s health and capacity to handle the load.

This guide will help you check for common problems that cause the log ” send message failed [channel: ” + 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: ” + 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);


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?