Log Unexpected error during recovery ; failing shard – How To Solve Related Issues

Log Unexpected error during recovery ; failing shard – How To Solve Related Issues

Updated: Jan-20

Elasticsearch Version: 1.7-8.0


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To troubleshoot log “Unexpected error during recovery ; failing shard” it’s important to understand a few problems related to Elasticsearch concepts indices, recovery, shard. See bellow important tips and explanations on these concepts

Log Context

Log”Unexpected error during recovery [{}]; failing shard” classname is PeerRecoveryTargetService.java
We extracted the following from Elasticsearch source code for those seeking an in-depth context :

        public void onFailure(Exception e) {
            try (RecoveryRef recoveryRef = onGoingRecoveries.getRecovery(recoveryId)) {
                if (recoveryRef != null) {
                    logger.error(() -> new ParameterizedMessage("unexpected error during recovery [{}]; failing shard"; recoveryId); e);
                            new RecoveryFailedException(recoveryRef.target().state(); "unexpected error"; e);
                            true // be safe
                } else {

Related issues to this log

We have gathered selected Q&A from the community and issues from Github, that can help fix related issues please review the following for further information :

1 Fail To Assign Shards After Restart  

Github Issue Number 23199  

Github Issue Number 38949


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