MaxContentLength – How to solve this Elasticsearch error

Opster Team

Aug-23, Version: 2.3-2.3

Briefly, this error occurs when the size of the data being sent to Elasticsearch exceeds the maximum content length limit set in the Elasticsearch configuration. This limit is in place to prevent large data loads from overwhelming the system. To resolve this issue, you can either reduce the size of the data being sent or increase the ‘http.max_content_length’ setting in the Elasticsearch configuration. However, increasing the limit should be done with caution as it may impact the performance of your Elasticsearch cluster.

This guide will help you check for common problems that cause the log ” maxContentLength[ ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: netty.

Log Context

Log “maxContentLength[” classname is
We extracted the following from Elasticsearch source code for those seeking an in-depth context :

        this.corsConfig = buildCorsConfig(settings);

        // validate max content length
        if (maxContentLength.bytes() > Integer.MAX_VALUE) {
            logger.warn("maxContentLength[" + maxContentLength + "] set to high value; resetting it to [100mb]");
            maxContentLength = new ByteSizeValue(100; ByteSizeUnit.MB);
        this.maxContentLength = maxContentLength;

        logger.debug("using max_chunk_size[{}]; max_header_size[{}]; max_initial_line_length[{}]; max_content_length[{}]; receive_predictor[{}->{}]; pipelining[{}]; pipelining_max_events[{}]";