OpenSearch An operation was attempted on a shard that is not recovering.

What is OpenSearch An operation was attempted on a shard that is not recovering.

Understanding OpenSearch

OpenSearch is a powerful, open-source search and analytics suite derived from Elasticsearch. It is designed to provide fast, scalable, and reliable search capabilities for a variety of applications, from log analytics to full-text search. OpenSearch is widely used for its robust features and flexibility, making it a popular choice for developers and businesses alike.

Identifying the Symptom

When working with OpenSearch, you might encounter the IndexShardNotRecoveringException. This error typically manifests when an operation is attempted on a shard that is not in the recovering state. The error message might look something like this:

{ "error": "IndexShardNotRecoveringException", "reason": "An operation was attempted on a shard that is not recovering."}

Understanding the Issue

The IndexShardNotRecoveringException is an indication that a specific shard within your OpenSearch index is not in the expected state for the operation you are trying to perform. Shards are the basic building blocks of an OpenSearch index, and they need to be in the correct state to handle operations like indexing or searching. If a shard is not recovering, it means it is not in the process of being restored or initialized, which can prevent certain operations from being executed.

Common Causes

Network issues causing delays in shard recovery. Insufficient resources, such as memory or CPU, leading to stalled recovery processes. Configuration errors that prevent shards from entering the recovering state.

Steps to Fix the Issue

To resolve the IndexShardNotRecoveringException, you need to ensure that the shard is in a recovering state before performing any operations. Here are the steps you can follow:

Step 1: Check Shard Status

Use the following command to check the status of your shards:

GET /_cat/shards?v

This command will provide a list of all shards and their current states. Look for shards that are not in the STARTED or INITIALIZING states.

Step 2: Investigate Logs

Check the OpenSearch logs for any errors or warnings related to shard recovery. Logs can provide insights into why a shard is not recovering. The logs are typically located in the logs directory of your OpenSearch installation.

Step 3: Allocate Resources

If resource constraints are causing the issue, consider allocating more memory or CPU to your OpenSearch nodes. You can adjust these settings in the opensearch.yml configuration file.

Step 4: Restart Nodes

In some cases, restarting the OpenSearch nodes can help resolve recovery issues. Use the following command to restart a node:

systemctl restart opensearch

Ensure that you restart nodes one at a time to avoid cluster downtime.

Additional Resources

For more information on managing shards and troubleshooting OpenSearch, consider visiting the following resources:

OpenSearch Documentation OpenSearch Community Forum OpenSearch GitHub Issues