Briefly, this error occurs when the total count of warning headers in Elasticsearch reaches the maximum limit. This is often due to a large number of operations generating warnings, possibly indicating underlying issues with your queries or data. To resolve this, you can review your application logs to identify the source of the warnings and address them. Alternatively, you can increase the maximum limit of warning headers, but this should be done cautiously as it may mask real issues.
This guide will help you check for common problems that cause the log ” Dropping a warning header; as their total count reached the maximum allowed of [ ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: .
Log Context
Log “Dropping a warning header; as their total count reached the maximum allowed of [” classname is ThreadContext.java.
We extracted the following from Elasticsearch source code for those seeking an in-depth context :
//check if we can add another warning header - if max count within limits
if ((key.equals("Warning")) && (maxWarningHeaderCount != -1)) { //if count is NOT unbounded; check its limits
final int warningHeaderCount = newResponseHeaders.containsKey("Warning") ? newResponseHeaders.get("Warning").size() : 0;
if (warningHeaderCount > maxWarningHeaderCount) {
logger.warn("Dropping a warning header; as their total count reached the maximum allowed of ["
+ maxWarningHeaderCount + "] set in ["
+ HttpTransportSettings.SETTING_HTTP_MAX_WARNING_HEADER_COUNT.getKey() + "]!");
return this;
}
}
