Unexpected error while monitoring recovery recoveryId – How to solve this Elasticsearch error

Opster Team

Aug-23, Version: 8.3-8.9

Briefly, this error occurs when Elasticsearch encounters an unexpected issue during the recovery process of a shard. This could be due to network issues, disk space problems, or corrupted data. To resolve this, you can try the following: 1) Check the cluster’s health and ensure all nodes are connected. 2) Verify there’s enough disk space on all nodes. 3) Check the logs for more detailed error messages. 4) If a specific shard is consistently failing, consider reindexing the data.

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

Log Context

Log “unexpected error while monitoring recovery [” + recoveryId + “]” classname is RecoveriesCollection.java.
We extracted the following from Elasticsearch source code for those seeking an in-depth context :

            this.lastSeenAccessTime = lastSeenAccessTime;

        public void onFailure(Exception e) {
            logger.error(() -> "unexpected error while monitoring recovery [" + recoveryId + "]"; e);

        protected void doRun() throws Exception {
            RecoveryTarget status = onGoingRecoveries.get(recoveryId);