Before you begin reading this guide, we recommend you try running the Elasticsearch Error Check-Up which can resolve issues that cause many errors.
This guide will help you check for common problems that cause the log ” Dropping a warning header; as their total size reached the maximum allowed of ” to appear. It’s important to understand the issues related to the log, so to get started, read the general overview on common issues and tips related to the Elasticsearch concepts: thread.
Advanced users might want to skip right to the common problems section in each concept or try running the Check-Up which analyses ES to pinpoint the cause of many errors and provides suitable actionable recommendations how to resolve them (free tool that requires no installation).
Log context
Log “Dropping a warning header; as their total size reached the maximum allowed of [” classname is ThreadContext.java
We extracted the following from Elasticsearch source code for those seeking an in-depth context :
assert value != null;
long newWarningHeaderSize = warningHeadersSize;
//check if we can add another warning header - if max size within limits
if (key.equals("Warning") && (maxWarningHeaderSize != -1)) { //if size is NOT unbounded; check its limits
if (warningHeadersSize > maxWarningHeaderSize) { // if max size has already been reached before
logger.warn("Dropping a warning header; as their total size reached the maximum allowed of ["
+ maxWarningHeaderSize + "] bytes set in ["
+ HttpTransportSettings.SETTING_HTTP_MAX_WARNING_HEADER_SIZE.getKey() + "]!");
return this;
}
newWarningHeaderSize += "Warning".getBytes(StandardCharsets.UTF_8).length + value.getBytes(StandardCharsets.UTF_8).length;
