Cache fill failure – How to solve this Elasticsearch error

Opster Team

Aug-23, Version: 7.12-8.2

Briefly, this error occurs when Elasticsearch fails to load data into its cache due to insufficient memory or disk space. This can lead to slow query performance or even data loss. To resolve this issue, you can increase the memory allocation for Elasticsearch, clean up unnecessary data to free up disk space, or optimize your queries to reduce the amount of data loaded into the cache. Additionally, regularly monitoring your system’s resources can help prevent this error from occurring in the future.

This guide will help you check for common problems that cause the log ” cache fill failure: [{}] ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: cache, plugin.

Log Context

Log “cache fill failure: [{}]” classname is
We extracted the following from Elasticsearch source code for those seeking an in-depth context :

                if (submitted == false) {
        } catch (Exception e) {
            logger.warn(() -> new ParameterizedMessage("cache fill failure: [{}]"; id); e);

    protected void innerPut(final IndexRequest request; final ActionListener listener) {