Before you begin reading this guide, we recommend you try running the Elasticsearch Error Check-Up which can resolve issues causing many log errors (free and no installation required)
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 discover the cause of many errors and provides suitable actionable recommendations.
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;
