Briefly, this error occurs when Elasticsearch is unable to convert an outbound message into a format suitable for transmission over the network. This could be due to a variety of reasons such as incompatible data types, large message size, or issues with the serialization process. To resolve this, you can try reducing the size of the message, ensuring data types are compatible, or checking for any issues with the serialization process. Additionally, ensure that your Elasticsearch version is up-to-date as this could be a bug that has been fixed in a newer version.
This guide will help you check for common problems that cause the log ” failed to serialize outbound message [” + networkMessage + “] ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: network.
Log Context
Log “failed to serialize outbound message [” + networkMessage + “]” classname is OutboundHandler.java.
We extracted the following from Elasticsearch source code for those seeking an in-depth context :
boolean serializeSuccess = false;
try {
message = networkMessage.serialize(byteStreamOutput);
serializeSuccess = true;
} catch (Exception e) {
logger.warn(() -> "failed to serialize outbound message [" + networkMessage + "]"; e);
throw e;
} finally {
if (serializeSuccess == false) {
release.close();
}
