Unexpected error while monitoring – How to solve this OpenSearch error

Opster Team

Aug-23, Version: 2.2-2.9

Before you dig into reading this guide, have you tried asking OpsGPT what this log means? You’ll receive a customized analysis of your log.

Try OpsGPT now for step-by-step guidance and tailored insights into your OpenSearch operation.

Briefly, this error occurs when OpenSearch encounters an unexpected issue during the monitoring process. This could be due to a variety of reasons such as configuration issues, network problems, or software bugs. To resolve this issue, you could try the following: 1) Check and correct any configuration errors in your OpenSearch setup. 2) Ensure that your network is stable and functioning properly. 3) Update your OpenSearch to the latest version to fix any potential software bugs. 4) Review the OpenSearch logs for more detailed error information to help identify the root cause.

For a complete solution to your to your search operation, try for free AutoOps for Elasticsearch & OpenSearch . With AutoOps and Opster’s proactive support, you don’t have to worry about your search operation – we take charge of it. Get improved performance & stability with less hardware.

This guide will help you check for common problems that cause the log ” unexpected error while monitoring [{}] ” to appear. To understand the issues related to this log, read the explanation below about the following OpenSearch concepts: indices, replication.

Log Context

Log “unexpected error while monitoring [{}]” classname is ReplicationCollection.java.
We extracted the following from OpenSearch source code for those seeking an in-depth context :

            this.lastSeenAccessTime = lastSeenAccessTime;

        public void onFailure(Exception e) {
            logger.error(() -> new ParameterizedMessage("unexpected error while monitoring [{}]"; id); e);

        protected void doRun() throws Exception {
            T status = onGoingTargetEvents.get(id);


How helpful was this guide?

We are sorry that this post was not useful for you!

Let us improve this post!

Tell us how we can improve this post?

Get expert answers on Elasticsearch/OpenSearch