PreIndex listener listener failed – How to solve this Elasticsearch error

Opster Team

Aug-23, Version: 8.3-8.9

Briefly, this error occurs when a pre-index operation listener fails to execute properly. This could be due to a variety of reasons such as incorrect configuration, network issues, or a bug in the listener code. To resolve this issue, you can try the following: 1) Check the listener’s configuration and ensure it’s correct. 2) Investigate network connectivity if the listener is remote. 3) Review the listener’s code for any potential bugs or issues. 4) Check the Elasticsearch logs for more detailed error messages that can help pinpoint the problem.

This guide will help you check for common problems that cause the log ” preIndex listener [” + listener + “] failed ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: index, shard.

Log Context

Log “preIndex listener [” + listener + “] failed” classname is
We extracted the following from Elasticsearch source code for those seeking an in-depth context :

            assert operation != null;
            for (IndexingOperationListener listener : listeners) {
                try {
                    listener.preIndex(shardId; operation);
                } catch (Exception e) {
                    logger.warn(() -> "preIndex listener [" + listener + "] failed"; e);
            return operation;