Failed to serialize outbound message - Common causes and quick fixes

Failed to serialize outbound message – How to solve this Elasticsearch error

Opster Team

Aug-23, Version: 7.14-8.2

Briefly, this error occurs when Elasticsearch is unable to convert an outbound message into a format that can be transmitted over the network. This could be due to a variety of reasons such as incompatible data types, large size of the message, or issues with the serialization process. To resolve this issue, you can try reducing the size of the message, ensuring that the data types are compatible, or checking for any issues with the serialization process. If the problem persists, consider debugging the serialization process to identify and fix the underlying issue.

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

Log Context

Log “failed to serialize outbound message [{}]” classname is OutboundHandler.java.
We extracted the following from Elasticsearch source code for those seeking an in-depth context :

        final ActionListener wrappedListener = ActionListener.runBefore(listener; byteStreamOutput::close);
        final BytesReference message;
        try {
            message = networkMessage.serialize(byteStreamOutput);
        } catch (Exception e) {
            logger.warn(() -> new ParameterizedMessage("failed to serialize outbound message [{}]"; networkMessage); e);
            wrappedListener.onFailure(e);
            throw e;
        }
        internalSend(channel; message; networkMessage; wrappedListener);
    }