Opster Team
Before you begin reading this guide, we recommend you run Elasticsearch Error Check-Up which analyzes 2 JSON files to detect many errors.
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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: thread.

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; } }
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CTO at Omnidots